Method and device for evaluating psychological state during work, and method and device for evaluating the enjoyment of work itself

Abstract

To provide a new device capable of objectively evaluating a psychological state of a person doing work according to a work task with a relatively high degree of reliability.SOLUTION: The present invention includes a step for imparting a work task, a step for acquiring data on a cerebral blood flow, and a step for evaluation. In a work task imparting step S100, a work task is imparted to a subject. In a cerebral blood flow data acquisition step S200, a cerebral blood flow of the frontal pole of the brain of the subject is continuously measured by NIRS from a rest state before work to a rest state after work through the work, and cerebral blood flow measurement data is acquired. In an evaluation step S300, a first blood flow change rate indicating a proportion of a cerebral blood flow when working to a cerebral blood flow in the rest state before work, and a second blood flow change rate indicating a proportion of a cerebral blood flow in the rest state after work to the cerebral blood flow in the rest state before work are calculated from the measurement data. Then, on the basis of the first and second blood flow change rates, it is evaluated whether the subject is in a positive psychological state when working.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a method and device for evaluating a psychological state during work, and a method and device for evaluating the enjoyment of the work itself. [Background technology]

[0002] NIRS (near-infrared spectroscopy) has been known as a method for evaluating the state of oxygenation in blood and changes in cerebral blood flow by measuring changes in the concentration of hemoglobin in the blood of the brain using near-infrared light. This method is superior to other methods for evaluating brain function, such as fMRI (functional magnetic resonance imaging), PET, and electroencephalography, in that it is possible to evaluate brain function relatively easily while performing a task. Therefore, by measuring brain function using NIRS (hereinafter also simply referred to as "brain NIRS"), it is possible to non-invasively confirm changes in the brain when performing some action. For this reason, in recent years, it has been proposed to use brain NIRS to, for example, (A) the cognitive load in conversation (see Patent Document 1), (B) evaluate cognitive function when subjects perform tasks of different difficulty (see Patent Document 2), (C) investigate the comfort of riding in a train and the impression of advertisements on the train, and (D) investigate taste. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-151217 A [Patent Document 2] JP 2020-130630 A Summary of the Invention [Problem to be solved by the invention]

[0004] By the way, for example, there are cases where we want to evaluate the psychological state (whether or not a worker feels enjoyment or motivation, etc.) of a worker who has been given some kind of task while performing the task. However, it is very difficult to evaluate the psychological state while performing the task, and currently, we ask the worker for his / her impressions after completing the task or conduct questionnaire surveys. These methods only provide subjective evaluations, and there is no effective method yet for objectively evaluating the psychological state while performing the task. In addition, questionnaire surveys and the like can only evaluate the subjective psychological state of the worker, and it is very difficult to objectively evaluate the enjoyment of the task itself.

[0005] It may be possible to use brain NIRS to evaluate the psychological state during work or the enjoyment of the work itself, but no specific methods have been proposed to date. Even if it were possible to grasp the state of brain activation using brain NIRS while the work is actually being performed, there is currently no effective knowledge about the correlation between the psychological state during work or the enjoyment of the work itself and the state of brain activation. Therefore, even if it is estimated that "the worker will feel enjoyment or motivation" when the brain is in an activated state during work, and that "the work itself will be enjoyable," the reliability and objectivity of the estimation results will naturally be low.

[0006] The present invention has been made in view of the above technical problems, and an object of the present invention is to provide a novel method and device capable of objectively evaluating with a relatively high degree of reliability the psychological state of a person performing a task according to a given task. Another object of the present invention is to provide a novel method and device capable of objectively evaluating with a relatively high degree of reliability the enjoyment of the task itself when a task is given and the person is made to perform the task according to the given task. [Means for solving the problem]

[0007] Through research using brain NIRS, the inventors have confirmed that imagining a situation accompanied by a change in emotion increases activation of the frontal pole of the brain. Therefore, they hypothesized that creative work is accompanied by a change in emotion, such as fun or interest, compared with simple work, and as a result, "a difference occurs in the change in cerebral blood flow during creative work and simple work." To verify this, they used NIRS using time-resolved spectroscopy (TRS) to compare the change in cerebral blood flow in the frontal pole of the brain when performing creative work in response to a creative work task with the change in cerebral blood flow in the frontal pole of the brain when performing simple work in response to a simple work task. As a result, it was found that 1) the increase in cerebral blood flow during creative work and in a resting state after the work was significantly greater than the increase in cerebral blood flow during simple work and in a resting state after the work (first finding). In other words, it was found that when performing creative work, the brain activation state continues not only during the work but also surprisingly in a resting state after the work (a delay is observed in the convergence of the brain activation state). In addition, 2) contrary to expectations, it was found that the increase in cerebral blood flow in the resting state after creative work was greater than the increase in cerebral blood flow during creative work (second finding). Furthermore, 3) the results of the subjective survey (Visual Analogue Scale (VAS) value) showed that the VAS value, which indicates feelings of motivation and enjoyment, was significantly higher during creative work (third finding). Therefore, from these findings, the hypothesis that "there is a difference in changes in cerebral blood flow during creative work and simple work" was correct, and it was confirmed that activity in the frontal pole of the brain is increased during work accompanied by positive feelings such as enjoyment. Therefore, the inventors further conducted intensive research based on the above findings, and ultimately completed the following invention.

[0008] Means for solving the above technical problems are listed below in [1] to

[21] . [1] A method for evaluating a psychological state when performing work in accordance with a given work task, comprising: a task assignment step of assigning the task to a subject; a cerebral blood flow data acquisition step of continuously measuring cerebral blood flow in the frontal pole of the brain of the subject by near-infrared spectroscopy from a pre-task resting state through the work to a post-task resting state, and acquiring measurement data relating to the cerebral blood flow; and an evaluation step of calculating, from the acquired measurement data, a first blood flow change rate indicating the ratio of cerebral blood flow during work to the cerebral blood flow in the pre-task resting state, and a second blood flow change rate indicating the ratio of cerebral blood flow in the post-task resting state to the cerebral blood flow in the pre-task resting state, and evaluating whether the subject was in a positive psychological state while working based on the first blood flow change rate and the second blood flow change rate. [2] The evaluation method described in 1 above, wherein in the cerebral blood flow data acquisition step, the oxygenated hemoglobin concentration is measured by the near-infrared spectroscopy, and in the evaluation step, the first blood flow change rate indicating the ratio of the oxygenated hemoglobin concentration during work to the oxygenated hemoglobin concentration in a resting state before work and the second blood flow change rate indicating the ratio of the oxygenated hemoglobin concentration in a resting state after work to the oxygenated hemoglobin concentration in a resting state before work are calculated, and when the first blood flow change rate and the second blood flow change rate are both values ​​exceeding 100% and the second blood flow change rate is greater than the first blood flow change rate, it is determined that the subject was in a positive psychological state while working. [3] The evaluation method described in 1 above, wherein in the cerebral blood flow data acquisition step, oxygenated hemoglobin concentration is measured by the near-infrared spectroscopy, and in the evaluation step, the first blood flow change rate indicating the ratio of the oxygenated hemoglobin concentration during work to the oxygenated hemoglobin concentration in a resting state before work and the second blood flow change rate indicating the ratio of the oxygenated hemoglobin concentration in a resting state after work to the oxygenated hemoglobin concentration in a resting state before work are calculated, and the first blood flow change rate and the second blood flow change rate are compared with a reference first blood flow change rate and a reference second blood flow change rate that are pre-stored as reference value data, respectively, to perform the evaluation. [4] In the task assignment step, two types of task are assigned to the subject, a creative task and a control simple task, and in the cerebral blood flow data acquisition step, the oxygenated hemoglobin concentration is measured by the near-infrared spectroscopy during a period from a pre-task resting state at the time of assignment of the creative task to a post-task resting state through the work and during a period from a pre-task resting state at the time of assignment of the simple task to a post-task resting state through the work. In the evaluation step, the first blood flow change rate and the second blood flow change rate at the time of assignment of the creative task are measured. the first blood flow change rate when the creative task is assigned is greater than the second blood flow change rate when the creative task is assigned, and the second blood flow change rate when the creative task is assigned is greater than the second blood flow change rate when the creative task is assigned. [5] The evaluation method described in any one of 1 to 4 above, wherein in the evaluation step, the positive psychological state is a psychological state accompanied by at least one emotion or state selected from enjoyment, motivation, concentration, alertness, and favorability. [6] A device for evaluating the psychological state when performing a task according to a given task, which uses near-infrared spectroscopy to measure the psychological state from a pre-task resting state through the task to a post-task resting state. Covered A psychological state evaluation device during work, comprising: a cerebral blood flow data acquisition device that continuously measures cerebral blood flow in the frontal pole of the examiner's brain and acquires measurement data regarding cerebral blood flow; and an evaluation means that calculates from the acquired measurement data a first blood flow change rate indicating the ratio of cerebral blood flow during work to the cerebral blood flow in the resting state before work, and a second blood flow change rate indicating the ratio of cerebral blood flow in the resting state after work to the cerebral blood flow in the resting state before work, and evaluates whether the subject was in a positive psychological state while working based on the first blood flow change rate and the second blood flow change rate. [7] The evaluation device described in 6 above, wherein the evaluation means calculates the first blood flow change rate indicating the ratio of the oxygenated hemoglobin concentration during work to the oxygenated hemoglobin concentration in the resting state before work, and the second blood flow change rate indicating the ratio of the oxygenated hemoglobin concentration in the resting state after work to the oxygenated hemoglobin concentration in the resting state before work, and determines that the subject was in a positive psychological state while working when the first blood flow change rate and the second blood flow change rate are both values ​​exceeding 100% and the second blood flow change rate is greater than the first blood flow change rate. [8] The evaluation device described in claim 6, further comprising a storage means for storing a reference first blood flow change rate and a reference second blood flow change rate in advance as reference value data, wherein the evaluation means calculates the first blood flow change rate indicating a ratio of the oxygenated hemoglobin concentration during work to the oxygenated hemoglobin concentration in the pre-work resting state, and the second blood flow change rate indicating a ratio of the oxygenated hemoglobin concentration in the post-work resting state to the oxygenated hemoglobin concentration in the pre-work resting state, and performs the evaluation by comparing the first blood flow change rate and the second blood flow change rate with the reference first blood flow change rate and the reference second blood flow change rate, respectively. [9] When a creative task and a control simple task are given to the subject as the two types of task, the cerebral blood flow data acquisition device measures the oxygenated hemoglobin concentration by the near-infrared spectroscopy during a period from a pre-task resting state at the time of giving the creative task to a post-task resting state through the work and during a period from a pre-task resting state at the time of giving the simple task to a post-task resting state through the work, and the evaluation means calculates the first blood flow change rate and the second blood flow change rate at the time of giving the creative task. The evaluation device described in claim 6, further comprising: a first blood flow change rate and a second blood flow change rate calculated when the simple task is assigned; and, when the first blood flow change rate when the creative task is assigned is greater than the first blood flow change rate when the simple task is assigned, and when the second blood flow change rate when the creative task is assigned is greater than the second blood flow change rate when the simple task is assigned, the device determines that the subject was in a positive psychological state when performing the task corresponding to the creative task.

[10] covered 10. The evaluation device according to any one of claims 6 to 9, further comprising a task assignment means for assigning the task to an examiner.

[11] The evaluation device according to any one of claims 6 to 10, further comprising a display device for displaying an evaluation result by the evaluation means.

[12] A method for evaluating the enjoyment of a task itself when a task is assigned to a subject and the subject is made to perform the task, comprising: a task assignment step of assigning the task to a subject; a cerebral blood flow data acquisition step of continuously measuring cerebral blood flow in the frontal pole of the subject's brain by near-infrared spectroscopy from a pre-task resting state, through the work, to a post-task resting state, and acquiring measurement data relating to the cerebral blood flow; and an evaluation step of calculating, from the acquired measurement data, a first blood flow change rate indicating the ratio of cerebral blood flow during work to the cerebral blood flow in the post-task resting state to the cerebral blood flow in the pre-task resting state, and a second blood flow change rate indicating the ratio of cerebral blood flow in the post-task resting state to the cerebral blood flow in the pre-task resting state, and evaluating whether the task itself is enjoyable based on the first blood flow change rate and the second blood flow change rate.

[13] The evaluation method described in 12 above, wherein in the cerebral blood flow data acquisition step, the oxygenated hemoglobin concentration is measured by the near-infrared spectroscopy, and in the evaluation step, the first blood flow change rate indicating the ratio of the oxygenated hemoglobin concentration during work to the oxygenated hemoglobin concentration in a resting state before work and the second blood flow change rate indicating the ratio of the oxygenated hemoglobin concentration in a resting state after work to the oxygenated hemoglobin concentration in a resting state before work are calculated, and when the first blood flow change rate and the second blood flow change rate are both values ​​exceeding 100% and the second blood flow change rate is greater than the first blood flow change rate, the work itself is judged to be enjoyable.

[14] The evaluation method described in 12 above, wherein in the cerebral blood flow data acquisition step, oxygenated hemoglobin concentration is measured by the near-infrared spectroscopy, and in the evaluation step, the first blood flow change rate indicating the ratio of the oxygenated hemoglobin concentration during work to the oxygenated hemoglobin concentration in a resting state before work and the second blood flow change rate indicating the ratio of the oxygenated hemoglobin concentration in a resting state after work to the oxygenated hemoglobin concentration in a resting state before work are calculated, and the first blood flow change rate and the second blood flow change rate are compared with a reference first blood flow change rate and a reference second blood flow change rate that are pre-stored as reference value data, respectively, to perform the evaluation.

[15] In the task assignment step, two types of task are assigned to the subject, a creative task and a control simple task, and in the cerebral blood flow data acquisition step, the oxygenated hemoglobin concentration is measured by the near-infrared spectroscopy during a period from a pre-task resting state at the time of assignment of the creative task to a post-task resting state through the work and during a period from a pre-task resting state at the time of assignment of the simple task to a post-task resting state through the work. In the evaluation step, the first blood flow change at the time of assignment of the creative task is measured. the first blood flow change rate and the second blood flow change rate are calculated, and the first blood flow change rate and the second blood flow change rate are calculated when the creative task is assigned, and if the first blood flow change rate when the creative task is assigned is greater than the first blood flow change rate when the simple task is assigned, and if the second blood flow change rate when the creative task is assigned is greater than the second blood flow change rate when the creative task is assigned, the creative task itself is judged to be enjoyable.

[16] A device for evaluating the enjoyment of a task itself when a task is given and a subject is made to perform the task, the device being used to measure the enjoyment of the task itself by near-infrared spectroscopy from a pre-task resting state through the task to a post-task resting state. Covered A device for evaluating the enjoyment of a task itself, comprising: a cerebral blood flow data acquisition device that continuously measures cerebral blood flow in the frontal pole of the examiner's brain and acquires measurement data regarding cerebral blood flow; and an evaluation means that calculates from the acquired measurement data a first blood flow change rate indicating the ratio of cerebral blood flow during work to the cerebral blood flow in the resting state before work, and a second blood flow change rate indicating the ratio of cerebral blood flow in the resting state after work to the cerebral blood flow in the resting state before work, and evaluates whether the task itself is enjoyable based on the first blood flow change rate and the second blood flow change rate.

[17] The evaluation device described in claim 16, wherein the evaluation means calculates the first blood flow change rate indicating the ratio of the oxygenated hemoglobin concentration during work to the oxygenated hemoglobin concentration in the resting state before work, and the second blood flow change rate indicating the ratio of the oxygenated hemoglobin concentration in the resting state after work to the oxygenated hemoglobin concentration in the resting state before work, and determines that the work itself is enjoyable when the first blood flow change rate and the second blood flow change rate are both values ​​exceeding 100% and the second blood flow change rate is greater than the first blood flow change rate.

[18] The evaluation device described in claim 16, further comprising a memory means for storing a reference first blood flow change rate and a reference second blood flow change rate in advance as reference value data, wherein the evaluation means calculates the first blood flow change rate indicating a ratio of the oxygenated hemoglobin concentration during work to the oxygenated hemoglobin concentration in the pre-work resting state, and the second blood flow change rate indicating a ratio of the oxygenated hemoglobin concentration in the post-work resting state to the oxygenated hemoglobin concentration in the pre-work resting state, and performs the evaluation by comparing the first blood flow change rate and the second blood flow change rate with the reference first blood flow change rate and the reference second blood flow change rate, respectively.

[19] In a case where a creative task and a control simple task are given to a subject as two types of the task, the cerebral blood flow data acquisition device measures the oxygenated hemoglobin concentration by the near-infrared spectroscopy during a period from a pre-task resting state at the time of giving the creative task to a post-task resting state through the work and during a period from a pre-task resting state at the time of giving the simple task to a post-task resting state through the work, and the evaluation means measures the first blood flow change rate and the second blood flow change rate at the time of giving the creative task. The evaluation device described in 16 above, which calculates the blood flow change rate, and calculates the first blood flow change rate and the second blood flow change rate when the simple task is assigned, and when the first blood flow change rate when the creative task is assigned is compared with the first blood flow change rate when the simple task is assigned and the second blood flow change rate when the creative task is assigned is compared with the second blood flow change rate when the simple task is assigned, the creative task itself is judged to be enjoyable.

[20] covered 20. The evaluation device according to any one of claims 16 to 19, further comprising a task assignment means for assigning the task to an examiner.

[21] The apparatus for evaluating the enjoyment of a task itself described in any one of claims 16 to 20, further comprising a display device for displaying the evaluation result by the evaluation means. Effect of the Invention

[0009] As described above in detail, the inventions described in claims 1 to 11 can provide a novel method and device capable of objectively evaluating with a relatively high degree of reliability the psychological state of a person performing a task according to a given task. Also, the inventions described in claims 12 to 21 can provide a novel method and device capable of objectively evaluating with a relatively high degree of reliability the enjoyment of the task itself when a task is given and the person is made to perform the task according to the task. [Brief description of the drawings]

[0010] [Figure 1] FIG. 4 is an explanatory diagram for explaining a procedure of a verification test according to the first embodiment. [Diagram 2] FIG. 1 is a schematic diagram for explaining the position of the probe in the brain NIRS performed in the above-mentioned verification test. [Diagram 3] 13 is a graph showing the results of a subjective survey in the above verification test. [Figure 4] 4 is a graph showing changes in hemoglobin concentration when performing simple tasks in the above verification test. [Diagram 5] 11 is a graph showing the change in hemoglobin concentration when creative work was performed in the above verification test. [Figure 6] Graph showing the average rate of change in oxy-Hb for each section and condition when performing tasks according to the task in the above verification test. [Figure 7] 1 is a graph showing the average rate of change in deoxy-Hb for each section and condition when performing tasks according to the task in the above verification test. [Figure 8] FIG. 11 is a block diagram for explaining an operation psychological state assessment device according to a second embodiment. [Figure 9] 4 is a flowchart for explaining a series of steps for evaluating a psychological state during work using the device. [Figure 10] 4 is a flowchart for explaining details of a psychological state evaluation step during work by the device. [Figure 11] 10 is another flowchart for explaining details of the psychological state evaluation step during work by the device. [Figure 12] 11 is a flowchart for explaining a series of steps for evaluating the enjoyment of an activity itself using the activity enjoyment evaluation device of the third embodiment. [Figure 13] 10 is a flowchart for explaining details of a step of evaluating the enjoyment of the task itself using the device. [Figure 14] 10 is another flowchart for explaining details of the step of evaluating the enjoyment of the task itself by the device. [Figure 15]13 is a flowchart for explaining details of an at-work psychological state evaluation step performed by the at-work psychological state evaluation device of the fourth embodiment. [Figure 16] 13 is a flowchart for explaining details of the enjoyment of an activity itself evaluation step performed by the enjoyment of an activity itself evaluation device of the fifth embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [First embodiment] In this embodiment, in order to verify the hypothesis that creative work is accompanied by changes in emotions such as fun and interesting compared to simple work, and as a result, "a difference occurs in the change in cerebral blood flow between creative work and simple work," the following verification test was performed. In this verification test, the change in cerebral blood flow in the frontal pole of the brain when performing creative work according to a creative work task and the change in cerebral blood flow in the frontal pole of the brain when performing simple work according to a simple work task were measured by NIRS using time-resolved spectroscopy (TRS), and the two were compared. In addition, a subjective survey was also conducted in which the results were scored. Note that the "task" referred to here is preferably a task that requires a certain amount of time to perform, for example, a time in minutes (i.e., not a task that can be performed in a few seconds). However, this time is not particularly limited and is arbitrary, and the time required for the task does not necessarily have to be in minutes, as long as it can be measured and evaluated by NIRS, including repeating a task for a few seconds to a dozen seconds multiple times. In this embodiment, the task that requires a time in minutes is set, because it is generally considered that a creation often requires a time in minutes at least, and by setting the time required for the task to be longer, it is easier to obtain sufficient measurement data, which is considered to lead to an increase in the reliability of the evaluation results. In this case, the task may be set to require a time of, for example, 1 minute or more, preferably 3 minutes or more, and more preferably 5 minutes or more.

[0012] Figure 1 is an explanatory diagram for explaining the procedure of this verification test. In this verification test, two types of work tasks (creative work task and simple work task) were set as work tasks to observe the brain activation state, in which participants actually moved their hands to handle parts. In this case, "Screw Blocks (registered trademark of Hashimoto Screw Co., Ltd.)" were used to perform these work tasks. "Screw Blocks" are toys that use screws, and various objects such as various animals and robots can be created by assembling blocks by connecting them with screws. In this verification test, the "creative work task" was set to create a specific dog using the "Screw Blocks." On the other hand, the "simple work task" was set to repeatedly fasten and remove hexagonal screws to hexagonal bolt screws (length 5 cm) included in the "Screw Blocks."

[0013] In this verification test, a time-resolved spectroscopy system (manufactured by Hamamatsu Photonics, product name "TRS-41") was used to measure the brain activation state during work by NIRS. Figure 2 is a schematic diagram for explaining the position of the probe in brain NIRS. Here, the international electroencephalogram 10-20 method Fpz was used as a reference, and a probe unit 1 was attached to the left and right foreheads. The left and right probe units 1 each have an irradiation probe 2, a first detection probe 3, and a second detection probe 4. The irradiation probe 2 is located at the farthest position from the center of the forehead, the first detection probe 3 is located 1.5 cm away from the irradiation probe 2, and the second detection probe 4 is located 3 cm away from the irradiation probe 2. The right probe unit 1 was designated "Ch1" and the left probe unit 1 was designated "Ch2".

[0014] Then, in each of the creative task and simple task tasks described above, the brain activation state was measured by NIRS in the pre-task resting state, during the task, and the post-task resting state. More specifically, in this verification test, NIRS measurements were performed twice. In the first measurement, the creative task or simple task was given in advance, and the subject was first asked to rest for 3 minutes before the task, then to perform a task using screws (creative task or simple task) for 7 minutes, and then to rest again for 3 minutes after the task. At this time, NIRS cerebral blood flow measurements were performed continuously (at a sampling rate of 0.33 Hz) from the 3-minute pre-task resting state through the 7-minute task to the 3-minute post-task resting state. After the first measurement was completed and before the second measurement was performed, the subject was asked to take a break (about 5 minutes) while filling out the results on a subjective survey form for the first task. In the second measurement, the subjects were given a creative task or a simple task beforehand, and then they were asked to rest for 3 minutes before the task, then to perform a task using screws (creative task or simple task) for 7 minutes, and then to rest for 3 minutes after the task. In this case, NIRS was used to measure cerebral blood flow continuously from the 3-minute pre-task resting state to the 7-minute task and the 3-minute post-task resting state. However, for subjects who were given a creative task and performed creative tasks in the first measurement, a simple task task was given in the second measurement. For subjects who were given a simple task and performed simple tasks in the first measurement, a creative task task was given in the second measurement. After the second measurement, the subjects were asked to fill in the results of the subjective survey on the second task. Incidentally, in this verification test, 24 healthy adult male and female volunteers were used as subjects, and the analysis was performed using data from 23 subjects, excluding one case in which data analysis was not possible due to body movement. In this verification test, as described above, it is preferable that the time for the pre-work rest state and the post-work rest state is shorter than the time during work and is at least one minute. If the time for the pre-work rest state and the post-work rest state is too short, it may be difficult to obtain sufficient measurement data, which may affect the reliability of the evaluation results.Also, if the time for the pre-work resting state and the post-work resting state is too long, while it becomes easier to obtain sufficient measurement data, it takes a long time to obtain the evaluation results.

[0015] A subjective survey was conducted using a Visual Analogue Scale (VAS), which consisted of the following seven questions about the psychological state during work, with participants being asked to rate each question numerically, with 0 being the minimum and 100 being the maximum. Q1: "Fun" → The higher the number, the more "fun" it was Q2: "Level of concentration" → The higher the number, the more "concentrated" you were. Q3: "Difficulty" → The higher the number, the "it was more difficult" Q4: "Motivation" → The higher the number, the more "motivated" Q5: "Level of alertness" → The higher the number, the more "awake" you felt (the lower the number, the more "drowsy" you felt). Q6: "Fatigue level" → The higher the number, the more "I feel less tired" (the lower the number, the more "tired") Q7: "Do you like or dislike (favor)?" → The higher the number, the more likely it is that you "like (favor)"

[0016] The cerebral blood flow data obtained by NIRS was analyzed, the "average rate of change" of hemoglobin concentration for 23 subjects was calculated, and the significant difference between creative work and simple work was examined. The analysis was performed using a conventional method. There are three types of hemoglobin concentration that can be measured by NIRS: oxygenated hemoglobin concentration, reduced hemoglobin concentration, and total hemoglobin concentration.

[0017] The method of analyzing the cerebral blood flow data will be specifically described below. First, the oxygenated hemoglobin concentration, the deoxygenated hemoglobin concentration, and the total hemoglobin concentration were added and averaged for all subjects analyzed (23 subjects), and the average value for each was calculated. For convenience, the average oxygenated hemoglobin concentration thus obtained will be referred to as "oxy-Hb", the average deoxygenated hemoglobin concentration as "deoxy-Hb", and the average total hemoglobin concentration as "total-Hb".

[0018] For oxy-Hb, deoxy-Hb, and total-Hb, the average value of the 10 data points (approximately 33 seconds) before the pre-task resting state (Rest pre) was used as the reference value, and the value of each data point was divided by the reference value to calculate the rate of change (%). In addition, the average rate of change (%) was calculated for each condition ("creative work" and "simple work") and for each section ("rest pre1", "rest pre2", "rest pre3", "task1", ​​"task2", "task3", "task4", "task5", "task6", "task7", "rest post1", "rest post2", and "rest post3" (total of 13 sections). In addition, in the group analysis, the average rate of change for each section of the 23 individuals was calculated, and a two-way analysis of variance [task condition (2; simple task vs. creative task) × section (13; rest pre1 to rest post3)] and paired t-tests were used to compare the conditions between the creative task and simple task for each section.

[0019] Next, the results of the verification test will be explained. Figure 3 is a graph showing the results of the subjective survey. As shown in Figure 3, the subjective survey showed that the VAS values ​​of the creative work were significantly higher than the VAS values ​​of the simple work in six categories: "enjoyment," "concentration," "difficulty," "motivation," "alertness," and "like or dislike (favorability)" (p<0.001). On the other hand, no significant difference was observed between the creative work and simple work in terms of "fatigue level." From the above, it was confirmed that the subjects engaged in the creative work "with positive feelings such as motivation and enjoyment."

[0020] Figure 4 is a graph showing the waveform of hemoglobin concentration change when subjects performed simple tasks. As is clear from the graph, when subjects performed simple tasks, the average rate of change in oxy-Hb, deoxy-Hb, and total-Hb tended to gradually decrease during the tasks and when they were at rest after the tasks. In addition, the rate of decrease in the rate of change tended to increase over time.

[0021] On the other hand, Figure 5 is a graph showing the waveform of hemoglobin concentration changes when subjects performed creative work. As is clear from the graph in this figure, the average rate of change in oxy-Hb when the subjects performed creative work increased while working, and tended to increase further when they were at rest after working. Similarly, the average rate of change in deoxy-Hb tended to gradually decrease while working and when they were at rest after working. Similarly, the average rate of change in total-Hb did not show much fluctuation throughout the study.

[0022] Figure 6 is a graph showing the average rate of change in oxy-Hb for each section and condition when performing tasks according to the task. As is clear from the graph in this figure, there was no significant difference in the average rate of change in oxy-Hb in the resting state before the task when comparing creative tasks and simple tasks. In contrast, the average rate of change in oxy-Hb during the task and in the resting state after the task was significantly higher in the creative task than in the simple task. This tendency was observed in both the left and right frontal poles, but was particularly noticeable in the right frontal pole. Specifically, for example, there was a significant difference in the average rate of change in oxy-Hb during the task and in the resting state after the task in simple tasks in a total of six sections: "task2", "task3", "task6", "task7", "rest post1", "rest post2", and "rest post3". On the other hand, regarding the average rate of change in oxy-Hb during creative work and in the resting state after work, there were significant differences in a total of 13 sections, namely, all sections, including "task1", ​​"task2", "task3", "task4", "task5", "task6", "task7", "rest post1", "rest post2", and "rest post3". Moreover, 12 of those sections showed extremely high significant differences (p<0.001).

[0023] Figure 7 is a graph showing the average rate of change in deoxy-Hb for each section and condition when performing tasks according to the task. As is clear from the graph, no significant difference was observed in the average rate of change in deoxy-Hb in the resting state before the task when comparing creative work and simple work. In contrast, the average rate of change in deoxy-Hb during the task and in the resting state after the task in the left frontal pole was significantly lower in the creative task than in the simple task. Furthermore, the average rate of change in deoxy-Hb during the task in the right frontal pole was significantly lower in the creative task than in the simple task.

[0024] From the results of the above verification test, it was proven that creative work is accompanied by changes in emotions such as fun and interesting compared to simple work, and as a result, the hypothesis that "there is a difference in changes in cerebral blood flow during creative work and simple work" is correct. Specifically, it was found that the activity of the frontal pole of the brain was higher during creative work accompanied by fun and motivation and in the resting state after the work, and the cerebral blood flow (oxygenated hemoglobin concentration) increased significantly. At that time, it was also found that the increase in cerebral blood flow (oxygenated hemoglobin concentration) was greater in the resting state after the work than during the work. In addition, a subjective survey conducted at the same time showed that the VAS value, which indicates the emotions of motivation and fun, was significantly higher during creative work. Therefore, considering these results in relation to each other, it was concluded that it is possible to objectively evaluate the psychological state of the subject with a relatively high degree of reliability by measuring cerebral blood flow using NIRS and investigating whether the increase in cerebral blood flow (oxygenated hemoglobin concentration) during work and in the resting state after the work shows the above-mentioned characteristic pattern. Similarly, we concluded that if we investigate whether the increase in cerebral blood flow (oxygenated hemoglobin concentration) during work and while at rest after work shows the characteristic pattern described above, it would be possible to objectively evaluate the enjoyment of the work itself with a relatively high degree of reliability.

[0025] [Second embodiment]

[0026] A second embodiment of an apparatus and method for assessing a psychological state during work according to the present invention will now be described in detail with reference to FIGS.

[0027] The working psychological state evaluation device 11 of this embodiment is a device for evaluating the psychological state of a subject when performing a task according to a given task, and is basically completed based on the conclusion obtained in the above-mentioned first embodiment. As shown in Fig. 8, this device 11 is composed of a cerebral blood flow data acquisition device 21, a personal computer (PC) 31, and a task assignment means 41.

[0028] The cerebral blood flow data acquisition device 21 of this embodiment is a device that continuously measures the cerebral blood flow in the frontal pole of the brain of the subject by near-infrared spectroscopy (NIRS) and acquires measurement data related to the cerebral blood flow. This cerebral blood flow data acquisition device 21 is configured to include a probe holding band 22. The probe holding band 22 holds a pair of probe units 1 that irradiate and receive measurement light in the near-infrared wavelength region to the left and right frontal poles of the brain of the subject. Each probe unit 1 has an irradiation probe 2, a first detection probe 3, and a second detection probe 4. The measurement light irradiated by the irradiation probe 2 is reflected inside the head and then enters the first detection probe 3 and the second detection probe 4. As a result, measurement data related to the intensity (amount of received light) of the measurement light is acquired. Here, in order to measure the amount of change in oxygenated hemoglobin as an index of the change in cerebral blood flow, measurement light of a wavelength that matches the absorption characteristics of oxygenated hemoglobin is irradiated.

[0029] The personal computer (PC) 31 includes an I / F circuit 32, an input device 33, a display device 34, a CPU 35, a storage device 36, and a memory 37, and these devices are connected to each other via a bus so as to be able to communicate with each other. The I / F circuit 32 is an input / output circuit interposed between the PC 31 and an external device, and is electrically connected to the cerebral blood flow data acquisition device 21 and the task assignment means 41. The measurement data acquired by the cerebral blood flow data acquisition device 21 is input into the PC 31 via the I / F circuit 32. In addition, the display data generated by the PC 31 is output to the task assignment means 41 via the I / F circuit 32. The CPU 35 executes various controls based on a control program. The storage device 36 is a hard disk drive (HDD) such as a magnetic disk device or an optical disk device, or a solid state drive (SSD), and stores various control programs. In the storage device 36, for example, a task assignment program, a cerebral blood flow data acquisition / measurement program, a task psychological state evaluation program, an evaluation result display program, and the like are stored as the various control programs. The memory 37 includes a RAM (random access memory) and a ROM (read only memory), and temporarily stores various data, for example. The CPU 31 transfers programs and data from the storage device 36 to the memory 37 in accordance with a predetermined instruction, and executes them sequentially.

[0030] The input device 33 is a device for inputting various parameters, requests and instructions from the user, and may be, for example, a keyboard, a touch panel, a mouse, a pointing device, etc. The display device 34 is a device for visually displaying the results of the evaluation of the psychological state during work, and may be, for example, a monitor device such as an LCD display, a plasma display, an organic EL display, etc. The task assignment means 41 is a device for assigning task to the subject visually and aurally, and may be, for example, a device such as a tablet PC, etc.

[0031] In this embodiment, the CPU 35 functions as an evaluation means for evaluating whether the subject was in a positive psychological state while working based on the cerebral blood flow measurement data. The CPU 35 as an evaluation means calculates a first blood flow change rate (%) and a second blood flow change rate (%) based on the oxygenated hemoglobin concentration calculated from the acquired cerebral blood flow measurement data. Here, the "first blood flow change rate" is defined as the ratio of the oxygenated hemoglobin concentration during work to the oxygenated hemoglobin concentration in the resting state before work. The "second blood flow change rate" is defined as the ratio of the oxygenated hemoglobin concentration in the resting state after work to the oxygenated hemoglobin concentration in the resting state before work. More specifically, the ratio of the average value of the oxygenated hemoglobin concentration in the right frontal pole during work (seven intervals from "task1" to "task7" in the first embodiment) to the oxygenated hemoglobin concentration in the right frontal pole during pre-work resting state (the "rest pre1" interval in the first embodiment) was defined as "first blood flow change rate". Also, the ratio of the average value of the oxygenated hemoglobin concentration in the right frontal pole during post-work resting state (three intervals from "rest post1" to "rest post3") to the oxygenated hemoglobin concentration in the right frontal pole during pre-work resting state (the "rest pre1" interval in the first embodiment) was defined as "second blood flow change rate". Incidentally, the "first blood flow change rate" and the "second blood flow change rate" are defined as above in the present embodiment, but they are merely examples and are not limited thereto.

[0032] The RAM 37 as a storage means stores the reference first blood flow change rate and the reference second blood flow change rate as reference value data in advance. The "reference first blood flow change rate" is a value that is determined by first calculating the first blood flow change rate using the measurement data of 23 subjects obtained in the verification test of the first embodiment and referring to this. The "reference first blood flow change rate" in this embodiment is set to, for example, 100.5(%). The "reference second blood flow change rate" is a value that is determined by first calculating the second blood flow change rate using the measurement data of 23 subjects obtained in the verification test of the first embodiment and referring to this. The "reference second blood flow change rate" in this embodiment is set to, for example, 101.5(%). Incidentally, the reference second blood flow change rate is somewhat higher than the reference first blood flow change rate.

[0033] The CPU 35 compares the first and second blood flow change rates obtained by the measurement with predetermined reference values ​​(e.g., a reference first blood flow change rate and a reference second blood flow change rate), respectively, to evaluate whether the subject was in a positive psychological state while working. More specifically, based on the first and second blood flow change rates obtained by the measurement, when the first and second blood flow change rates are both values ​​exceeding 100% and the second blood flow change rate is greater than the first blood flow change rate, it is determined that the subject was in a positive psychological state while working. In addition, based on the results of the subjective survey obtained in the verification test of the first embodiment, the "positive psychological state" is defined as a psychological state accompanied by at least one emotion or state selected from enjoyment, motivation, concentration, awakening, and favor.

[0034] Next, a series of steps for evaluating psychological state during work using the device 11 will be described based on the flow chart of FIG. 9. Here, a person other than the 23 subjects in the first embodiment is selected as the subject. The number of subjects may be one or more. First, the probe holding band 22 of the cerebral blood flow data acquisition device 21 is attached to the frontal area of ​​the subject. In this state, information about the subject is inputted by the input device 33 and information instructing the start of measurement is inputted. Then, the CPU 35 moves to a task assignment step and executes a predetermined process (step S100). That is, the CPU 35 drives the tablet PC, which is the task assignment means 41, and assigns a predetermined task to the subject. Here, the same creative task as in the first embodiment, that is, the task of making a predetermined dog using "screw blocks" is assigned. Specifically, an image of a dog assembled using screw blocks is displayed, and text and voice are outputted to instruct the subject to assemble the dog using screw blocks within a certain time. At this time, text may be displayed or audio may be output to explain that the work time is 7 minutes, and that the person should rest for 3 minutes before and after the work. In this embodiment, the work task is assigned using a tablet PC, but the work task may be assigned using a device other than a tablet PC (such as an interactive robot). Alternatively, the work task may be assigned by a human being without relying on such devices.

[0035] Next, the CPU 35 proceeds to a cerebral blood flow data acquisition step and executes a predetermined process (step S200). That is, the CPU 35 takes in the output signal (measurement data) from the cerebral blood flow data acquisition device 21 and sequentially stores it in the memory 37. In this embodiment, the acquisition of cerebral blood flow data is performed continuously throughout the pre-task resting state (3 minutes), the work (7 minutes), and the post-task resting state (3 minutes) when the above creative task is given.

[0036] Next, the CPU 35 proceeds to an evaluation step for evaluating the psychological state during work and executes a predetermined process (step S300). FIG. 10 is a flowchart for explaining the details (subroutine) of the evaluation step. In the evaluation step, the CPU 35 calculates a first blood flow change rate from the acquired cerebral blood flow measurement data (step S302) and calculates a second blood flow change rate (step S304). Next, the CPU 35 judges whether the calculated first blood flow change rate is a value exceeding 100, that is, whether the oxygenated hemoglobin concentration during work has increased compared to the resting state before work (step S306). If the first blood flow change rate is a value exceeding 100 (step S306: Y), the CPU 35 proceeds to the next step S308. If the first blood flow change rate is a value of 100 or less (step S306: N), the CPU 35 judges that "the subject was not in a positive psychological state during work" (step S314) and ends the evaluation step.

[0037] Next, the CPU 35 judges whether the calculated second blood flow change rate is a value exceeding 100%, i.e., whether the oxygenated hemoglobin concentration in the post-work resting state has increased compared to the pre-work resting state (step S308). If the second blood flow change rate is a value exceeding 100 (step S308: Y), the CPU 35 proceeds to the next step S310. If the second blood flow change rate is a value of 100 or less (step S308: N), the CPU 35 judges that "the subject was not in a positive psychological state while working" (step S314) and ends the evaluation step. In other words, when the CPU 35 reaches step S314, it is specifically judged that the subject did not have the feelings of "having fun," "being able to concentrate," "being motivated," "feeling awakened," or "liking (having a favorable attitude)" while working.

[0038] Next, the CPU 35 judges whether the second blood flow change rate is greater than the first blood flow change rate, that is, whether the oxygenated hemoglobin concentration in the resting state after the work has further increased compared to when the work was performed (step S310). If the second blood flow change rate is greater than the first blood flow change rate (step S310: Y), the CPU 35 judges that "the subject was in a positive psychological state when the work was performed" (step S312) and ends the evaluation step. If the second blood flow change rate is equal to or less than the first blood flow change rate (step S310: N), the CPU 35 judges that "the subject was in a positive psychological state similar to that at the time of the work, although not as positive as at the time of the work in step S312" (step S316) and ends the evaluation step. If the result is NO at step S310, specifically, it is judged that the subject had feelings of "enjoyment," "concentration," "motivation," "feeling awakened," and "liking (having a favorable attitude)" when the work was performed. Furthermore, if the answer is YES in step S310, it is determined that the subject had the following feelings while working: "It was very fun," "I was very concentrated," "I was very motivated," "I felt very awakened," and "I really liked it (had a favorable impression)." That is, in the evaluation step subroutine of FIG. 10, the above three-stage evaluation results are obtained.

[0039] Instead of the evaluation step subroutine of FIG. 10, for example, the evaluation step subroutine of FIG. 11 may be adopted. In the evaluation step subroutine of FIG. 11, steps S302 to S308 are common to FIG. 10, and therefore will not be described. After executing step S308, the CPU 35 proceeds to step S322, and compares the first blood flow change rate obtained by measurement with the reference first blood flow change rate (100.5%). If the first blood flow change rate is greater than the reference first blood flow change rate (step S322: Y), the CPU 35 proceeds to the next step S324. In step S324, the CPU 35 compares the second blood flow change rate obtained by measurement with the reference second blood flow change rate (101.5%). If the second blood flow change rate is greater than the reference second blood flow change rate (step S324: Y), the CPU 35 determines that "the subject was in a positive psychological state during the work" (step S312), and ends the evaluation step. When the first blood flow change rate is equal to or lower than the reference first blood flow change rate (step S322: N) and when the second blood flow change rate is equal to or lower than the reference second blood flow change rate (step S324: N), the CPU 35 judges that "the subject was in a positive psychological state equivalent to that in step S312 while working, though not to the same extent as in step S312" (step S316) and ends the evaluation step. When the judgment is No in steps S306 and S308, the CPU 35 judges that "the subject was not in a positive psychological state while working" (step S314) and ends the evaluation step. That is, the evaluation step subroutine of FIG. 11 also provides the above three-stage evaluation result.

[0040] After the evaluation step is completed, the CPU 35 proceeds to an evaluation result display step and executes a predetermined process (step S400). Specifically, the CPU 35 generates image display data including the evaluation result, and outputs the image display data to the display device 34. As a result, the display device 34 visualizes the evaluation result and displays it on the monitor screen.

[0041] Therefore, according to this embodiment, the following effects can be obtained.

[0042] (1) The working psychological state evaluation device 11 of this embodiment includes the above-mentioned cerebral blood flow data acquisition device 21, a PC 31 including a CPU 35 functioning as an evaluation means, and the like. The cerebral blood flow data acquisition device 21 continuously measures the cerebral blood flow in the frontal pole of the brain of the subject by NIRS from the pre-work resting state through the working state to the post-work resting state, and acquires measurement data related to the cerebral blood flow. The evaluation means calculates, from the acquired measurement data, a first blood flow change rate, which is the change rate of the cerebral blood flow during working based on the cerebral blood flow in the pre-work resting state, and a second blood flow change rate, which is the change rate of the cerebral blood flow in the post-work resting state based on the cerebral blood flow in the pre-work resting state. The evaluation means also evaluates whether the subject was in a positive psychological state during working based on the first blood flow change rate and the second blood flow change rate. In other words, this device 11 is novel in that it does not evaluate the working psychological state based only on the cerebral blood flow data during working, but evaluates the working psychological state based on the cerebral blood flow data during working and the post-work resting state. As mentioned above, the latter has a higher correlation between cerebral blood flow data and the psychological state during work. This is based on the fact that when creative work is performed, the brain continues to be activated not only during work but also during rest after work, and the increase in cerebral blood flow during rest after work is greater than the increase in cerebral blood flow during work. Therefore, according to this device 11 and the evaluation method using it, the psychological state of a person performing work according to a given task can be objectively and non-invasively evaluated with a relatively high degree of reliability.

[0043] (2) In particular, in the device 11 of this embodiment, the psychological state during work is determined using the processing procedure shown in Figure 10 or the processing procedure shown in Figure 11, so that it is possible to evaluate the psychological state during work in stages, for example, according to the degree of enjoyment, etc., or the reliability of the evaluation.

[0044] (3) The device 11 of this embodiment is equipped with a task assignment means 41 that assigns a task to the subject. The task assignment means 41 is not essential to the device 11 of the present invention and is an optional component, but by using such a task assignment means 41, the task can be presented without relying on human hands. This makes it possible to improve efficiency and reduce labor.

[0045] (4) The device 11 of the present embodiment includes a display device 34 that displays the evaluation results by the evaluation means. The display device 34 is not essential for the device 11 of the present invention but is an optional component. However, by using such a display device 34, it is possible to visualize the evaluation results and show them to the user in an easy-to-understand manner.

[0046] [Third embodiment]

[0047] Hereinafter, a third embodiment of the present invention, namely, an "apparatus and method for evaluating the enjoyment of an activity itself," will be described in detail with reference to Figs. 12 to 14. Note that the configuration of the apparatus 11 of this embodiment is basically the same as that of the second embodiment, so a detailed description thereof will be omitted and differences will be mainly described.

[0048] The CPU 35 as the evaluation means in this embodiment also evaluates whether the work given to the subject as a task is enjoyable or not by comparing the first blood flow change rate and the second blood flow change rate obtained by measurement with predetermined reference values ​​(e.g., a reference first blood flow change rate and a reference second blood flow change rate). More specifically, based on the first blood flow change rate and the second blood flow change rate obtained by measurement, when the first blood flow change rate and the second blood flow change rate are both values ​​exceeding 100% and the second blood flow change rate is larger than the first blood flow change rate, the CPU 35 judges that the work itself is enjoyable.

[0049] Next, a series of steps for evaluating the enjoyment of the work itself using the device 11 will be described based on the flowchart of FIG. 12. Here, a person other than the 23 subjects in the first embodiment is selected as the subject. The number of subjects may be one or more. Then, a task is given to the subject with the probe holding band 22 of the cerebral blood flow data acquisition device 21 attached to the forehead of the subject (step S100). At this time, a task that is already known to be enjoyable (for example, a task of making a specific dog using a "screw block") is not set as the task, but a task that is not yet known to be enjoyable or not is set as the task, and it is given to the subject. That is, a task that is not yet known to be a creative task is set as the task, rather than a task that is already known to be a creative task.

[0050] Specific examples of task tasks to be assigned include using "screw blocks" to make "other living creatures other than dogs (e.g., horses, elephants, birds, fish, insects, etc.)" and using "screw blocks" to make "non-living objects (e.g., robots, cars, airplanes, etc.)". Of course, tasks using toys other than "screw blocks" (e.g., building blocks, plastic models, puzzle rings, board games, card games, video games, etc.) and tasks using objects and tools that are not toys (e.g., hand tools such as scissors, knives, razors, forks, tweezers, screwdrivers, and hexagonal wrenches) may be the task. Furthermore, the task may be assembly work, processing work, inspection work, transportation work, etc., when actually manufacturing products at a manufacturing site such as a factory. Note that the task is not necessarily limited to tasks that involve hand movement, and may be tasks that involve moving parts of the body other than the hands (e.g., feet, face, etc.), or tasks that involve moving the whole body rather than a part of the body. Furthermore, the task is not limited to tasks that involve physical movement, and may be tasks that involve no or almost no physical movement (intellectual tasks such as calculations, writing compositions, and quizzes).

[0051] Next, the CPU 35 executes a process to acquire cerebral blood flow data (step S200), and then proceeds to a step of evaluating the enjoyment of the task itself (step S350). FIG. 13 is a flowchart for explaining a subroutine of the evaluation step. The evaluation step of the device 11 of this embodiment is common to steps S302 to S310 of the flowchart in FIG. 11. That is, the CPU 35 sequentially executes calculation of a first blood flow change rate, calculation of a second blood flow change rate, determination of whether the first blood flow change rate is a value exceeding 100%, determination of whether the second blood flow change rate is a value exceeding 100%, and determination of whether the second blood flow change rate is greater than the first blood flow change rate (steps S302 to S310).

[0052] Then, when the first blood flow change rate is 100% or less (step S306: N) or when the second blood flow change rate is 100% or less (step S308: N), the CPU 35 judges that "the task given as the task itself was not enjoyable" (step S354) and ends the evaluation step. When the second blood flow change rate is greater than the first blood flow change rate (step S310: Y), the CPU 35 judges that "the task given as the task itself was enjoyable" (step S352) and ends the evaluation step. When the second blood flow change rate is equal to or less than the first blood flow change rate (step S310: N), the CPU 35 judges that "the task given as the task itself was enjoyable, although not as enjoyable as in step S352" (step S356) and ends the evaluation step. That is, in the evaluation step subroutine of FIG. 13, the above three-stage evaluation result is obtained.

[0053] Note that, instead of the evaluation step subroutine of FIG. 13, for example, the evaluation step subroutine of FIG. 14 may be adopted. In the evaluation step subroutine of FIG. 14, steps S302 to S308 are common to FIG. 13, and therefore the description will be omitted. After executing step S308, the CPU 35 proceeds to step S322, and compares the first blood flow change rate obtained by measurement with the reference first blood flow change rate (100.5%). If the first blood flow change rate is greater than the reference first blood flow change rate (step S322: Y), the CPU 35 proceeds to the next step S324. In step S324, the CPU 35 compares the second blood flow change rate obtained by measurement with the reference second blood flow change rate (101.5%). If the second blood flow change rate is greater than the reference second blood flow change rate (step S324: Y), the CPU 35 determines that "the task given as the task itself was enjoyable" (step S352), and ends the evaluation step. When the first blood flow change rate is equal to or lower than the reference first blood flow change rate (step S322: N) and when the second blood flow change rate is equal to or lower than the reference second blood flow change rate (step S324: N), the CPU 35 judges that "the task given as the task itself was enjoyable, though not as enjoyable as in step S352" (step S356) and ends the evaluation step. When the judgment is No in steps S306 and S308, the CPU 35 judges that "the task given as the task itself was not enjoyable" (step S354) and ends the evaluation step. That is, the evaluation step subroutine of FIG. 14 also provides the above three-stage evaluation result.

[0054] After the evaluation step is completed, the CPU 35 proceeds to an evaluation result display step and executes a predetermined process (step S400). Specifically, the CPU 35 generates image display data including the evaluation result, and outputs the image display data to the display device 34. As a result, the display device 34 visualizes the evaluation result and displays it on the monitor screen.

[0055] The device 11 of the present embodiment configured as described above is novel in that it evaluates the enjoyment of the task itself not only based on the cerebral blood flow data during the task, but also based on the cerebral blood flow data during the task and in the resting state after the task. As described above, the latter has a higher correlation between the cerebral blood flow data and the enjoyment of the task itself. This is based on the fact that when creative work is performed, the brain is activated not only during the task but also in the resting state after the task, and the increase in the cerebral blood flow in the resting state after the task is greater than the increase in the cerebral blood flow during the task, which is a characteristic pattern of increase in the cerebral blood flow. Therefore, according to the device 11 and the evaluation method using the device, the enjoyment of the task itself can be objectively and non-invasively evaluated with a relatively high degree of reliability when a task is given and the corresponding task is performed. If the enjoyment of the task itself can be evaluated objectively using the device 11, it is expected that productivity will be improved through improvements in the task content, and therefore it is considered to be useful in industry.

[0056] (2) In particular, in the device 11 of this embodiment, the enjoyment of the task itself is judged by the processing procedure shown in FIG. 13 or the processing procedure shown in FIG. 14, so that it is possible to evaluate the task in stages according to, for example, the degree of enjoyment or the reliability of the evaluation.

[0057] (3) Furthermore, the device 11 of this embodiment is equipped with a task assignment means 41 and a display device 34. The task assignment means 41 can be configured as desired, but by using this, task assignments can be presented without relying on human intervention. This makes it possible to improve efficiency and reduce labor. The display device 34 can also be configured as desired, but by using this, it is possible to visualize the evaluation results and show them to the user in an easy-to-understand manner.

[0058] [Fourth embodiment]

[0059] A fourth embodiment of the present invention, namely, an "apparatus and method for assessing mental states during work," will be described in detail below with reference to Fig. 15. Note that the configuration of the apparatus 11 of this embodiment is basically the same as that of the second embodiment, so detailed description thereof will be omitted and differences will be mainly described.

[0060] This embodiment differs from the second and third embodiments in that, in addition to assigning the subject only the creative task to be evaluated and measuring brain NIRS, the subject is also assigned a simple task as a control and measuring brain NIRS. That is, two types of task are set as in the verification test in the first embodiment (see FIG. 1). The creative task to be evaluated may be a task that is already known to be a creative task, or a task that is not known to be a creative task but is expected to be a creative task.

[0061] The cerebral blood flow data acquisition device 21 of this embodiment continuously measures the oxygenated hemoglobin concentration using NIRS during the period from the pre-work resting state when a creative work task is assigned, through the work period, to the post-work resting state, and during the period from the pre-work resting state when a simple work task is assigned, through the work period, to the post-work resting state.

[0062] The CPU 35 as an evaluation means in this embodiment calculates the first blood flow change rate (%) and the second blood flow change rate (%) for each task based on the oxygenated hemoglobin concentration calculated from the acquired cerebral blood flow measurement data. Specifically, the CPU 35 calculates the first blood flow change rate (%) and the second blood flow change rate (%) when a creative task is assigned, and calculates the first blood flow change rate (%) and the second blood flow change rate (%) when a simple task is assigned. The CPU 35 further determines whether or not the subject was in a positive psychological state based on a comparison result between the first blood flow change rate when a creative task is assigned and the first blood flow change rate when a simple task is assigned, and a comparison result between the second blood flow change rate when a creative task is assigned and the second blood flow change rate when a simple task is assigned.

[0063] Next, a series of steps for evaluating the psychological state during work using the device 11 will be described. Here, a different subject unrelated to the subject in the first embodiment is selected. Then, as shown in the flowchart of FIG. 9, the following steps are performed in sequence: a work task is assigned (step S100), data on cerebral blood flow is acquired (step S200), the psychological state during work is evaluated (step S300), and the evaluation result is displayed (step S400). Specifically, for the first measurement, a simple work task is assigned, and the subject is asked to perform a three-minute pre-work rest, a seven-minute simple work, and a three-minute post-work rest, and then, for the second measurement, a creative work task is assigned, and the subject is asked to perform a three-minute pre-work rest, a seven-minute creative work, and a three-minute post-work rest. Here, the rest time and the work time are set to three minutes and seven minutes, respectively, but these times may be changed arbitrarily. In step S200, the oxygenated hemoglobin concentration is measured by brain NIRS from the pre-work rest state when the creative work task is assigned, through the work, to the post-work rest state (first measurement). Similarly, when a simple task is assigned, oxygenated hemoglobin concentration is measured using brain NIRS from the pre-task resting state through the task to the post-task resting state (second measurement).

[0064] FIG. 15 shows a subroutine for evaluating the psychological state during work in step S300. The CPU 35 first calculates the first blood flow change rate (%) for each work task. That is, the CPU 35 calculates the first blood flow change rate (%) when a creative work task is assigned and the first blood flow change rate (%) when a simple work task is assigned (step S332). Next, the CPU 35 calculates the second blood flow change rate (%) when a creative work task is assigned and the second blood flow change rate (%) when a simple work task is assigned (step S334). The CPU 35 then proceeds to step S336, where it compares the first blood flow change rate (%) when a creative work task is assigned and the first blood flow change rate (%) when a simple work task is assigned. If the comparison result shows that the first blood flow change rate (%) when a creative work task is assigned is greater than the first blood flow change rate (%) when a simple work task is assigned (step S336: Y), the CPU 35 proceeds to the next step S338. If not (step S336: N), the CPU 35 proceeds to another step S342, determines that "the subject was not in a positive psychological state when working," and ends the evaluation step. In step S338, the CPU 35 compares the second blood flow change rate (%) when the creative task is assigned with the second blood flow change rate (%) when the simple task is assigned. If the comparison result shows that the second blood flow change rate (%) when the creative task is assigned is greater than the second blood flow change rate (%) when the simple task is assigned (step S338: Y), the CPU 35 proceeds to the next step S340, determines that "the subject was in a positive psychological state when working," and ends the evaluation step. If not (step S338: N), the CPU 35 proceeds to another step S342, determines that "the subject was not in a positive psychological state when working," and ends the evaluation step.

[0065] The working psychological state evaluation device 11 and the evaluation method using the device according to the present embodiment described above can objectively and non-invasively evaluate the psychological state of a person performing a task according to a given task with a relatively high degree of reliability. In particular, the device 11 employing the processing procedure of FIG. 15 judges the working psychological state through a comparison between two types of task performed by the same subject. Therefore, for example, the influence of variation in cerebral blood flow measurement data caused by different subjects can be minimized.

[0066] [Fifth embodiment]

[0067] Hereinafter, a fifth embodiment of the present invention, "apparatus and method for evaluating the enjoyment of an activity itself," will be described in detail with reference to Fig. 16. Note that the apparatus 11 and the evaluation method using the apparatus of this embodiment are basically the same as those of the fourth embodiment, so detailed description thereof will be omitted and differences will be mainly described.

[0068] A series of steps for evaluating the enjoyment of the work itself using the device 11 of this embodiment is as shown in the flowchart of FIG. 12, and the following steps are performed in sequence: assigning a work task, acquiring data on cerebral blood flow, evaluating the enjoyment of the work itself, and displaying the evaluation results (steps S100 to S400). Here, as in the fourth embodiment, two measurements are performed with different types of work tasks. Specifically, for the first measurement, a simple work task is assigned, and the subject is asked to perform a three-minute pre-work rest, a seven-minute simple work, and a three-minute post-work rest, and then for the second measurement, a creative work task is assigned, and the subject is asked to perform a three-minute pre-work rest, a seven-minute creative work, and a three-minute post-work rest. In step S200, the oxygenated hemoglobin concentration is measured by brain NIRS from the pre-work rest state when the creative work task is assigned, through the work, to the post-work rest state (first measurement). Similarly, when a simple task is assigned, oxygenated hemoglobin concentration is measured using brain NIRS from the pre-task resting state through the task to the post-task resting state (second measurement).

[0069] FIG. 16 shows a subroutine for evaluating the enjoyment of the task itself in step S300. The processes in steps S332 to S338 are the same as those in the fourth embodiment shown in FIG. 15, and therefore will not be described. If the first blood flow change rate (%) when the creative task is assigned is equal to or less than the first blood flow change rate (%) when the simple task is assigned (step S336: N), the CPU 35 proceeds to another step S364, determines that "the task itself given as the task was not enjoyable," and ends the evaluation step. Also, if the second blood flow change rate (%) when the creative task is assigned is equal to or less than the second blood flow change rate (%) when the simple task is assigned (step S338: N), the CPU 35 proceeds to another step S364, determines that "the task itself given as the task was not enjoyable," and ends the evaluation step. On the other hand, if the first blood flow change rate (%) when the creative task is assigned is greater than the first blood flow change rate (%) when the simple task is assigned (step S336: Y), and the second blood flow change rate (%) when the creative task is assigned is greater than the second blood flow change rate (%) when the simple task is assigned (step S338: Y), the CPU 35 proceeds to the next step S362. Then, the CPU 35 determines that "the task itself given as the task was enjoyable" and ends the evaluation step.

[0070] The above-described device 11 for evaluating the enjoyment of the task itself and the evaluation method using the same according to the present embodiment can objectively and non-invasively evaluate the enjoyment of the task itself when a task is given and the subject performs the task with a relatively high degree of reliability. In particular, the device 11 employing the processing procedure of FIG. 16 judges the enjoyment of the creative task itself, which is the subject of evaluation, through a comparison between two types of task tasks performed by the same subject. Therefore, for example, the influence of the variation in the cerebral blood flow measurement data due to different subjects can be minimized. In addition, according to the device 11 and the evaluation method, the control simple task can be regarded as a kind of standard, and it can be understood whether the creative task to be evaluated is more enjoyable than the control simple task.

[0071] The embodiment of the present invention is merely an example, and may be modified as appropriate without departing from the spirit of the invention.

[0072] In the above embodiment, one device 11 is provided with one cerebral blood flow data acquisition device 21, but it may be provided with multiple cerebral blood flow data acquisition devices 21. With this configuration, it is possible to acquire cerebral blood flow measurement data for multiple subjects individually and simultaneously, and obtain evaluation results for multiple subjects in a short period of time. This makes it possible to further improve efficiency.

[0073] In the above embodiment, the predetermined evaluation was performed based on the cerebral blood flow measurement data of the right frontal pole, but this is not limiting. That is, the evaluation may be based on the cerebral blood flow measurement data of the left frontal pole, or on the cerebral blood flow measurement data of both the left and right frontal poles.

[0074] In the above embodiment, the predetermined evaluation is performed by focusing on the average value oxy-Hb of the oxygenated hemoglobin concentration among the cerebral blood flow measurement data, but the present invention is not limited to this. For example, the predetermined evaluation may be performed by using the average value deoxy-Hb of the reduced hemoglobin concentration, and in particular, the predetermined evaluation may be performed by using the average value deoxy-Hb of the reduced hemoglobin concentration in the left frontal pole. Specifically, in the evaluation step, a first blood flow change rate indicating the ratio of the reduced hemoglobin concentration during work to the reduced hemoglobin concentration in the resting state before work is calculated. Next, a second blood flow change rate indicating the ratio of the reduced hemoglobin concentration in the resting state after work to the reduced hemoglobin concentration in the resting state before work is calculated. Furthermore, the first blood flow change rate and the second blood flow change rate are compared with the reference first blood flow change rate and the reference second blood flow change rate, which are stored in advance as reference value data, respectively, to perform the evaluation. In the case where the verification result of the first embodiment is used as the basis, the reference first blood flow change rate and the reference second blood flow change rate may be set to, for example, "97.0%" and used as the reference data. It is also possible to perform a predetermined evaluation using both the average oxygenated hemoglobin concentration and the average reduced hemoglobin concentration, and in this case, it is possible to further increase the reliability of the evaluation.

[0075] In the second and third embodiments, the cerebral blood flow rate was measured by NIRS for one task, but it may be measured for two tasks. Also, in the second and third embodiments, the subjective survey after the task was omitted, but it may be used in combination.

[0076] A device such as a tablet PC used as the task assignment means 41 may be used as an information input device that may be operated by the subject himself. Specifically, for example, when a subjective survey is conducted on the subject in the cerebral blood flow data acquisition step, the subjective survey items are displayed on the screen of the tablet PC, which is the information input device, and the subject is asked to input a VAS value on the screen. In this way, the subjective survey can be conducted without relying on human labor, which makes it possible to achieve further efficiency and labor savings. In addition, the results of the subjective survey can be immediately imported into the PC 31 and stored in the memory 37 in association with the cerebral blood flow measurement data, etc. [Explanation of symbols]

[0077] 11: Psychological state evaluation device during work, evaluation device for the enjoyment of the work itself 13: CPU as an evaluation tool 21: Cerebral blood flow data acquisition device 34:Display device 37: Memory as a storage means 41: Work assignment assignment means

Claims

1. A method for evaluating a psychological state when performing a task according to a given task, comprising: a task assignment step of assigning the task to the subject; a cerebral blood flow data acquisition step of continuously measuring the cerebral blood flow in the frontal pole of the brain of the subject by near-infrared spectroscopy from a pre-task resting state through the work period to a post-task resting state, and acquiring measurement data relating to the cerebral blood flow; an evaluation step of calculating a first blood flow change rate indicating a ratio of cerebral blood flow during work to cerebral blood flow in a resting state before work from the acquired measurement data, and a second blood flow change rate indicating a ratio of cerebral blood flow in a resting state after work to cerebral blood flow in a resting state before work, and evaluating whether or not the subject was in a positive psychological state during work based on the first blood flow change rate and the second blood flow change rate; A method for evaluating a psychological state during work, comprising:

2. In the cerebral blood flow data acquisition step, an oxygenated hemoglobin concentration is measured by the near-infrared spectroscopy; In the evaluation step, Calculating the first blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration during work to an oxygenated hemoglobin concentration in a resting state before work, and the second blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration in a resting state after work to an oxygenated hemoglobin concentration in a resting state before work, When the first blood flow change rate and the second blood flow change rate are both values ​​exceeding 100% and the second blood flow change rate is greater than the first blood flow change rate, it is determined that the subject was in a positive psychological state during the work.

2. The method for evaluating a psychological state during work according to claim 1 .

3. In the cerebral blood flow data acquisition step, an oxygenated hemoglobin concentration is measured by the near-infrared spectroscopy; In the evaluation step, Calculating the first blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration during work to an oxygenated hemoglobin concentration in a resting state before work, and the second blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration in a resting state after work to an oxygenated hemoglobin concentration in a resting state before work, The evaluation is performed by comparing the first blood flow change rate and the second blood flow change rate with a reference first blood flow change rate and a reference second blood flow change rate that are stored in advance as reference value data.

2. The method for evaluating a psychological state during work according to claim 1 .

4. In the task assignment step, a creative task and a simple task as a control are assigned to the subject as two types of tasks; In the cerebral blood flow data acquisition step, an oxygenated hemoglobin concentration is measured by the near-infrared spectroscopy during a period from a pre-task resting state when the creative task is assigned through the work to a post-task resting state, and during a period from a pre-task resting state when the simple task is assigned through the work to a post-task resting state, In the evaluation step, calculating the first blood flow change rate and the second blood flow change rate when the creative task is assigned, and calculating the first blood flow change rate and the second blood flow change rate when the simple task is assigned; When the first blood flow change rate when the creative task is assigned is compared with the first blood flow change rate when the simple task is assigned, the former is greater than the latter, and when the second blood flow change rate when the creative task is assigned is compared with the second blood flow change rate when the simple task is assigned, the former is greater than the latter, it is determined that the subject was in a positive psychological state when performing the task corresponding to the creative task.

2. The method for evaluating a psychological state during work according to claim 1 .

5. 5. A method for evaluating psychological states during work according to claim 1, wherein in the evaluation step, the positive psychological state is a psychological state accompanied by at least one emotion or state selected from enjoyment, motivation, concentration, alertness, and favorability.

6. An apparatus for evaluating a psychological state when performing a task according to a given task, comprising: a cerebral blood flow data acquisition device that continuously measures cerebral blood flow in the frontal pole of the subject's brain by near-infrared spectroscopy from a pre-task resting state through the work period to a post-task resting state, and acquires measurement data relating to the cerebral blood flow; an evaluation means for calculating a first blood flow change rate indicating a ratio of cerebral blood flow during work to the cerebral blood flow in the resting state before work from the acquired measurement data, and a second blood flow change rate indicating a ratio of cerebral blood flow in the resting state after work to the cerebral blood flow in the resting state before work, and evaluating whether or not the subject was in a positive psychological state during work based on the first blood flow change rate and the second blood flow change rate; A psychological state assessment device during work, comprising:

7. The evaluation means includes: Calculating the first blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration during work to an oxygenated hemoglobin concentration in a resting state before work, and the second blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration in a resting state after work to an oxygenated hemoglobin concentration in a resting state before work, When the first blood flow change rate and the second blood flow change rate are both values ​​exceeding 100% and the second blood flow change rate is greater than the first blood flow change rate, it is determined that the subject was in a positive psychological state during the work.

7. The psychological state assessment device according to claim 6,

8. Further comprising a storage means for storing the reference first blood flow change rate and the reference second blood flow change rate as reference value data in advance; The evaluation means includes: Calculating the first blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration during work to an oxygenated hemoglobin concentration in a resting state before work, and the second blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration in a resting state after work to an oxygenated hemoglobin concentration in a resting state before work, The evaluation is performed by comparing the first blood flow change rate and the second blood flow change rate with the reference first blood flow change rate and the reference second blood flow change rate, respectively.

7. The psychological state assessment device according to claim 6,

9. When subjects are given two types of tasks, a creative task and a simple task as a control, the cerebral blood flow data acquisition device measures the oxygenated hemoglobin concentration by the near-infrared spectroscopy during a period from a pre-task resting state when the creative task is assigned through the work to a post-task resting state, and during a period from a pre-task resting state when the simple task is assigned through the work to a post-task resting state, The evaluation means includes: calculating the first blood flow change rate and the second blood flow change rate when the creative task is assigned, and calculating the first blood flow change rate and the second blood flow change rate when the simple task is assigned; When the first blood flow change rate when the creative task is assigned is compared with the first blood flow change rate when the simple task is assigned, the former is greater than the latter, and when the second blood flow change rate when the creative task is assigned is compared with the second blood flow change rate when the simple task is assigned, the former is greater than the latter, it is determined that the subject was in a positive psychological state when performing the task corresponding to the creative task.

7. The psychological state assessment device according to claim 6,

10. A psychological state evaluation device during work as described in any one of claims 6 to 9, further comprising a work task assignment means for assigning the work task to the subject.

11. 11. The apparatus for evaluating psychological states during work according to claim 6, further comprising a display device for displaying an evaluation result by said evaluation means.

12. A method for evaluating the enjoyment of a task itself when a task is given and a task is performed according to the task, comprising: a task assignment step of assigning the task to the subject; a cerebral blood flow data acquisition step of continuously measuring the cerebral blood flow in the frontal pole of the brain of the subject by near-infrared spectroscopy from a pre-task resting state through the work period to a post-task resting state, and acquiring measurement data relating to the cerebral blood flow; an evaluation step of calculating a first blood flow change rate indicating a ratio of cerebral blood flow during work to cerebral blood flow in a resting state before work from the acquired measurement data, and a second blood flow change rate indicating a ratio of cerebral blood flow in a resting state after work to cerebral blood flow in a resting state before work, and evaluating whether the work itself is enjoyable based on the first blood flow change rate and the second blood flow change rate; A method for evaluating the enjoyment of a task itself, comprising:

13. In the cerebral blood flow data acquisition step, an oxygenated hemoglobin concentration is measured by the near-infrared spectroscopy; In the evaluation step, Calculating the first blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration during work to an oxygenated hemoglobin concentration in a resting state before work, and the second blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration in a resting state after work to an oxygenated hemoglobin concentration in a resting state before work, When the first blood flow change rate and the second blood flow change rate are both values ​​exceeding 100% and the second blood flow change rate is greater than the first blood flow change rate, the task itself is determined to be enjoyable.

13. The method for evaluating the enjoyment of a task itself according to claim 12.

14. In the cerebral blood flow data acquisition step, an oxygenated hemoglobin concentration is measured by the near-infrared spectroscopy; In the evaluation step, Calculating the first blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration during work to an oxygenated hemoglobin concentration in a resting state before work, and the second blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration in a resting state after work to an oxygenated hemoglobin concentration in a resting state before work, The evaluation is performed by comparing the first blood flow change rate and the second blood flow change rate with a reference first blood flow change rate and a reference second blood flow change rate that are stored in advance as reference value data.

13. The method for evaluating the enjoyment of a task itself according to claim 12.

15. In the task assignment step, a creative task and a simple task as a control are assigned to the subject as two types of tasks; In the cerebral blood flow data acquisition step, an oxygenated hemoglobin concentration is measured by the near-infrared spectroscopy during a period from a pre-task resting state when the creative task is assigned through the work to a post-task resting state, and during a period from a pre-task resting state when the simple task is assigned through the work to a post-task resting state, In the evaluation step, calculating the first blood flow change rate and the second blood flow change rate when the creative task is assigned, and calculating the first blood flow change rate and the second blood flow change rate when the simple task is assigned; When the first blood flow change rate when the creative task is assigned is compared with the first blood flow change rate when the simple task is assigned, the former is greater than the latter, and when the second blood flow change rate when the creative task is assigned is compared with the second blood flow change rate when the simple task is assigned, the former is greater than the latter, the creative task itself is determined to be enjoyable.

13. The method for evaluating the enjoyment of a task itself according to claim 12.

16. A device for evaluating the enjoyment of a task itself when a task is given and a user is made to perform the task, comprising: a cerebral blood flow data acquisition device that continuously measures cerebral blood flow in the frontal pole of the subject's brain by near-infrared spectroscopy from a pre-task resting state through the work period to a post-task resting state, and acquires measurement data relating to the cerebral blood flow; an evaluation means for calculating a first blood flow change rate indicating a ratio of cerebral blood flow during work to cerebral blood flow in a resting state before work from the acquired measurement data, and a second blood flow change rate indicating a ratio of cerebral blood flow in a resting state after work to cerebral blood flow in a resting state before work, and evaluating whether the work itself is enjoyable or not based on the first blood flow change rate and the second blood flow change rate; An apparatus for evaluating the enjoyment of a task itself, comprising:

17. The evaluation means includes: Calculating the first blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration during work to an oxygenated hemoglobin concentration in a resting state before work, and the second blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration in a resting state after work to an oxygenated hemoglobin concentration in a resting state before work, When the first blood flow change rate and the second blood flow change rate are both values ​​exceeding 100% and the second blood flow change rate is greater than the first blood flow change rate, the task itself is determined to be enjoyable.

17. The apparatus for evaluating the enjoyment of a task itself according to claim 16.

18. Further comprising a storage means for storing the reference first blood flow change rate and the reference second blood flow change rate as reference value data in advance; The evaluation means includes: Calculating the first blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration during work to an oxygenated hemoglobin concentration in a resting state before work, and the second blood flow change rate indicating a ratio of an oxygenated hemoglobin concentration in a resting state after work to an oxygenated hemoglobin concentration in a resting state before work, The evaluation is performed by comparing the first blood flow change rate and the second blood flow change rate with the reference first blood flow change rate and the reference second blood flow change rate, respectively.

17. The apparatus for evaluating the enjoyment of a task itself according to claim 16.

19. When subjects are given two types of tasks, a creative task and a simple task as a control, the cerebral blood flow data acquisition device measures the oxygenated hemoglobin concentration by the near-infrared spectroscopy during a period from a pre-task resting state when the creative task is assigned through the work to a post-task resting state, and during a period from a pre-task resting state when the simple task is assigned through the work to a post-task resting state, The evaluation means includes: calculating the first blood flow change rate and the second blood flow change rate when the creative task is assigned, and calculating the first blood flow change rate and the second blood flow change rate when the simple task is assigned; When the first blood flow change rate when the creative task is assigned is compared with the first blood flow change rate when the simple task is assigned, the former is greater than the latter, and when the second blood flow change rate when the creative task is assigned is compared with the second blood flow change rate when the simple task is assigned, the former is greater than the latter, the creative task itself is determined to be enjoyable.

17. The apparatus for evaluating the enjoyment of a task itself according to claim 16.

20. An evaluation device for evaluating the enjoyment of a task itself, as described in any one of claims 16 to 19, further comprising a task assignment means for assigning the task to a subject.

21. 21. The apparatus for evaluating the enjoyment of an activity itself according to claim 16, further comprising a display device for displaying a result of the evaluation by said evaluation means.

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