Analysis method, brain activity activation method, method of changing sense, cosmetic evaluation method, and cosmetic design method

Abstract

To provide a novel technique related to a relation between activity of a part related to a reward system of a brain and sense stimulation.SOLUTION: An analysis method of sense stimulation of activating brain activity of an anterior part of prefrontal cortex includes: an acquisition step of acquiring a measurement result of brain activity of a part regarding secondary reward in a brain of a subject when the subject receives sense stimulation; and an analysis step of performing the acquisition step on a plurality of subjects for each of a plurality of types of sense stimulation and analyzing a relation between activation of the anterior part of prefrontal cortex and sense stimulation.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for analyzing sensory stimuli that activate brain activity in specific brain regions, a method for activating brain activity through sensory stimuli, a method for evaluating cosmetics, and a method for designing cosmetics. [Background technology]

[0002] It is known that the brain responds to various stimuli and activates different areas depending on the stimulus. For example, Patent Document 1 discloses a technique for inducing brain activity through stimulation and estimating the site of brain activity by performing positioning using predefined reference points. Furthermore, Patent Document 2 discloses a technology for increasing cerebral blood flow by applying vibration to a living body.

[0003] Furthermore, Non-Patent Document 1 discloses that viewing an attractive face induces activation of the medial orbitofrontal cortex (OFC). Non-Patent Document 2 also discloses that, when brain activation in newborns was examined in response to tactile stimulation, such as gentle skin stroking, which resembles emotional or social contact, women showed greater blood oxygen level-dependent (BOLD) responses (brushing vs. resting) in the bilateral orbitofrontal cortex (OFC), right ventral striatum, bilateral inferior striatum, cerebral cortex, and cerebellum compared to men.

[0004] Furthermore, as a result of their research, the inventors discovered that different areas of the brain of subjects who viewed face images were activated depending on the image resolution, and published this finding in Non-Patent Document 3. Non-Patent Document 3 discloses that significant differences in activity were observed between resolution conditions, particularly in the orbitofrontal cortex (mOFC) and the anterior prefrontal cortex (aPFC), which are known to be involved in secondary reward. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2019-162278

Patent document 2

Non-licensed literature

[0006] [Non-licensed document 1] J O'Doherty, J Winston, H Critchley, D Perrett, DM Burt, RJ Dolan, "Beauty in a smile: the role of medial orbitofrontal cortex in facial attractiveness", Neuropsychologia, Volume 41, Issue 2, 2003, p.147-155 (URL https: / / pure.mpg.de / rest / items / item_2614428 / component / file_2623264 / content) [Non-licensed document 2] Isabella LC Mariani Wigley, Malin Bjornsdotter, Noora M Scheinin, Harri Merisaari, Jani Saunavaara, Riitta Parkkola, Sabrina Bonichini, Rosario Montirosso, Linnea Karlsson, Hasse Karlsson, Jetro J Tuulari, "Infants' sex affects neural responses to affective touch in early infancy", Developmental Psychobiol, 2023 Nov;65(7):e22419(URL https: / / onlinelibrary.wiley.com / doi / pdfdirect / 10.1002 / dev.22419) [Non-licensed document 3] Takaya Oishi, Iori Okabe, Yoshihiro Hamanaka, Xiaoguang Yang, Koji Mizukoshi, Hiroyuki Tsuda, Hideaki Kawabata, "Exploring Human Attractiveness Recognition by EEG Using High-Resolution Facial Images Mimicking Actual Visual Environments 2," Abstracts of the 18th Spring Conference of the Japan Society of Kansei Engineering (2023), published November 1, 2023. Summary of the Invention [Problem to be solved by the invention]

[0007] The above techniques do not provide specific methods for activating the activity of specific brain regions. As a result of intensive research, the present inventors have found that there is a certain relationship between activation of brain regions and sensory stimulation.

[0008] Based on the above findings, the present invention aims to provide a novel technique relating to the relationship between sensory stimulation and activity in areas related to the brain's reward system. [Means for solving the problem]

[0009] [1] A method for analyzing sensory stimuli that activate brain activity in areas related to secondary rewards in a subject's brain when the subject receives a sensory stimulus, the method comprising: an acquisition step of acquiring measurement results of brain activity in areas related to secondary rewards in the subject's brain when the subject receives a sensory stimulus; and an analysis step of performing the acquisition step for multiple subjects, each for multiple types of sensory stimuli, and analyzing the relationship between the activation of the areas and the sensory stimulus through statistical analysis.

[0010] This configuration allows for objective analysis of the relationship between the activity of the brain's secondary reward-related areas and sensory stimuli, which can be useful in research to identify sensory stimuli that activate the brain's secondary reward-related areas, in other words, sensory stimuli that have the potential to induce attraction or pleasure.

[0011] [2] The analysis method described in [1], wherein the area is the anterior prefrontal cortex.

[0012] [3] The analytical method according to [1] or [2], wherein the sensory stimulus includes a tactile stimulus.

[0013] [4] The analytical method according to [3], wherein the tactile stimulus is given to the subject by bringing the subject into contact with an object.

[0014] [5] The analytical method described in [4], wherein the object is a cosmetic, and the tactile stimulus is given to the subject by the subject applying the cosmetic to their own skin.

[0015] This configuration makes it possible to objectively analyze the relationship between the activity of the brain's secondary reward-related areas and the tactile stimulation caused by the use of cosmetics, thereby supporting the evaluation and design of cosmetics from the perspective of tactile stimulation during actual use.

[0016] [6] The analysis method described in [4] or [5], wherein the plurality of sensory stimuli are given to the subject by bringing the subject into contact with a plurality of objects having different physical properties, and the analysis step includes a step of performing a correlation analysis between the brain activity and the physical properties and identifying the physical properties that are correlated with the brain activity.

[0017] This configuration makes it possible to analyze the activity of the brain regions involved in secondary rewards caused by contact with an object from the perspective of physical properties, which can be useful for evaluating and designing objects using their physical properties as indicators, for example, from the perspective of the attractiveness and pleasure felt when using them.

[0018] [7] The analytical method according to any one of [1] to [6], wherein the sensory stimulus includes an olfactory stimulus.

[0019] [8] The analytical method described in [7], wherein the plurality of sensory stimuli are given to the subject by having the subject smell the scents of a plurality of objects each containing different components, and the analysis step includes a step of identifying the components contained in common by the objects that had the effect of activating the brain activity.

[0020] This configuration allows for an objective analysis of the relationship between the activity of the brain's secondary reward-related areas and the components contained in the scent, which can be useful for evaluating and designing products from the perspective of the attractiveness and pleasure evoked by the scent.

[0021] [9] The analytical method according to any one of [1] to [8], wherein the sensory stimulus includes a visual stimulus.

[0022]

[10] The analysis method described in [9], wherein the plurality of sensory stimuli are given to the subject by presenting the subject with a plurality of images each comprising different design elements, and the analysis step includes a step of identifying design elements that are common to the images that had the effect of activating the brain activity.

[0023] This configuration makes it possible to analyze the activity of the brain regions related to secondary rewards evoked by viewing from the perspective of design elements, which can be useful for evaluating and designing designs from the perspective of, for example, the attractiveness and pleasure evoked by viewing them.

[0024]

[11] The analysis method according to any one of [1] to

[10] , wherein the analysis step includes a step of performing the statistical analysis for each age group of the subjects.

[0025]

[12] A method for evaluating a cosmetic, which evaluates the cosmetic using the physical properties determined by the analytical method described in [6] as indicators.

[0026] By adopting such a configuration, it is possible to evaluate cosmetics using their physical properties as indicators from the perspective of the attractiveness and pleasant sensation felt when used.

[0027]

[13] A method for evaluating cosmetics, which evaluates cosmetics using the components identified by the analytical method described in [8] as indicators.

[0028] By configuring in this way, cosmetics can be evaluated using ingredients as indicators from the perspective of the appeal and pleasure felt when used.

[0029]

[14] A cosmetic design method comprising: an evaluation step of evaluating a cosmetic using the physical properties identified by the analysis method described in [6] as indicators; and a design step of adjusting the physical properties of the cosmetic based on the evaluation.

[0030] By adopting such a configuration, it is possible to design cosmetics using physical properties as indicators from the perspective of the appeal and pleasant sensation felt when used.

[0031]

[15] A cosmetic design method comprising: an evaluation step of evaluating a cosmetic using the components identified by the analysis method described in [8] as indicators; and a design step of adjusting the amounts of the components based on the evaluation.

[0032] By using such a composition, it is possible to design cosmetics using ingredients as indicators from the perspective of the appeal and pleasure felt when using them.

[0033]

[16] A method of activating brain activity (excluding medical procedures) in which a subject applies a cosmetic to their skin, thereby activating brain activity in the area of the subject's brain related to secondary rewards.

[0034] By configuring it in this way, it is expected that the use of the cosmetic will activate brain activity in specific areas, resulting in attractiveness and a sense of pleasure.

[0035]

[17] A method of activating brain activity (excluding medical procedures) in which the subject is exposed to an object that has physical properties that make the subject feel comfortable when touched, thereby activating brain activity in the area of the subject's brain related to secondary rewards.

[0036] With this configuration, it is expected that contact with an object having specific physical properties will activate brain activity in a specific area, resulting in an attractive or pleasurable sensation.

[0037]

[18] A method for activating brain activity according to

[17] (excluding medical procedures), wherein the physical property is a property relating to the deformation of the object when a test specimen comes into contact with the object.

[0038]

[19] A method for activating brain activity (excluding medical procedures) in which olfactory stimulation is given to a subject, thereby activating brain activity in the area of the subject's brain related to secondary reward.

[0039] This configuration is expected to activate brain activity in specific areas through the scent, creating an appealing and pleasurable sensation.

[0040]

[20] A method of activating brain activity (excluding medical procedures) in which brain activity in the area of the subject's brain related to secondary reward is activated by providing the subject with visual stimuli.

[0041]

[21] The sensation change method described in

[20] , wherein the visual stimulus includes a stimulus expressed in multiple colors.

[0042]

[22] The method for changing sensations described in

[20] , wherein the visual stimulus includes a stimulus showing a three-dimensional shape.

[0043]

[23] A method of activating brain activity (excluding medical procedures) in which sensory stimuli are determined based on the age of the subject and are given to the subject, thereby activating brain activity in the area of the subject's brain related to secondary rewards.

[0044]

[24] A method for activating brain activity according to any one of

[16] to

[23] , wherein the area is the anterior prefrontal cortex.

[0045]

[25] A method for changing sensations by applying a sensory stimulus to a subject to change the way the subject feels about another sensory stimulus.

[0046]

[26] The method for changing sensations described in

[25] , wherein the sensory stimulation includes a tactile stimulation, and the tactile stimulation is given by bringing the subject into contact with an object having physical properties that make the subject feel comfortable when touched.

[0047]

[27] A method for changing sensations described in

[25] or

[26] , in which the sensory stimulation to be given to the subject is determined based on the age of the subject.

[0048]

[28] The sensation change method described in any of

[25] to

[27] , wherein the sensory stimulation includes an olfactory stimulation.

[0049]

[29] The method for changing sensations described in any of

[25] to

[28] , wherein the sensory stimulus includes a visual stimulus.

[0050]

[30] The method for changing sensations described in

[29] , wherein the visual stimulus includes a stimulus expressed in multiple colors.

[0051]

[31] The method for changing sensations described in

[29] or

[30] , wherein the visual stimulus includes a stimulus showing a three-dimensional shape. [Effects of the Invention]

[0052] According to the present invention, a novel technique can be provided regarding the relationship between activity in areas related to the brain's reward system and sensory stimulation. [Brief explanation of the drawings]

[0053] [Figure 1] FIG. 2 is a block diagram showing the functional configuration of the analysis device of the present embodiment. [Figure 2] FIG. 2 is a hardware configuration diagram of an information processing apparatus (analysis apparatus) according to the present embodiment. [Figure 3] 1 is a flowchart showing an outline of an analysis method according to the present embodiment. [Figure 4] 1 is a flowchart showing an overview of an analysis method for tactile stimulation according to the present embodiment. [Figure 5] 1 is a flowchart showing an overview of an analysis method of an olfactory stimulus according to the present embodiment. [Figure 6] 1 is a flowchart showing an overview of an analysis method for visual stimuli according to the present embodiment. [Figure 7] FIG. 10 shows the analysis results of Example 2 regarding tactile stimulation. [Figure 8] FIG. 10 shows the analysis results of Example 2 regarding tactile stimulation. [Figure 9] FIG. 10 shows the analysis results of Example 3 regarding visual stimulation. [Figure 10] FIG. 10 shows the analysis results of Example 4 regarding tactile stimulation. [Figure 11] FIG. 10 shows the analysis results of Example 5 regarding visual stimulation. [Figure 12] FIG. 10 shows the analysis results of Example 6 regarding visual stimulation. DETAILED DESCRIPTION OF THE INVENTION

[0054] The present invention relates to a technique for analyzing the relationship between activation of brain activity in specific brain regions, particularly regions related to secondary reward, and sensory stimulation, and a technique for activating brain activity in regions related to secondary reward through sensory stimulation. The present invention will be described in more detail below with reference to the accompanying drawings. While the drawings show preferred embodiments, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

[0055] For example, in this embodiment, the analysis method will be mainly described, and the configuration, operation, etc. of an analysis device that executes the method will also be described, but similar effects can be achieved by a computer program that causes a computer device to execute the method, etc. The program may be provided as a non-transitory computer-readable recording medium, or may be provided so as to be downloadable from an external server.

[0056] <1.Definition> In the present invention, the term "sensory stimulus" refers to a stimulus that can be recognized by a human sensory organ. Specifically, a sensory stimulus refers to a stimulus perceived by the five human senses, namely, sight, hearing, touch, taste, and smell. In the following, the sensory stimulus refers to a sensory stimulus within the range experienced in daily life, and does not include invasive stimuli. In this embodiment, an analysis of tactile and olfactory stimuli will be described in particular, but instead, the relationship between other sensory stimuli and brain activation may also be analyzed. It is preferable that the analysis be performed for each type of sensory stimulus.

[0057] In the present invention, "brain areas related to secondary rewards" refer to areas related to secondary rewards that satisfy higher-level needs, and in this embodiment, particularly refers to areas that are activated when a secondary reward is obtained (or when a secondary reward is felt). In this embodiment, "brain areas related to secondary rewards" refers to all brain areas that are activated in relation to secondary rewards. It is known that the areas activated in the brain vary depending on the type and content of the secondary reward. In the present invention, "brain areas related to secondary rewards" includes all areas that are activated in relation to any secondary reward.

[0058] As described above, the "area in the brain related to secondary reward" of the present invention is not limited to a specific area, but may include, for example, the medial orbitofrontal cortex and the anterior prefrontal cortex, as shown in Non-Patent Documents 1 to 3. In the following embodiment, the relationship between activation of brain activity and sensory stimulation will be analyzed, particularly for the anterior prefrontal cortex, which is a region of the brain related to secondary reward.

[0059] <2. Functional configuration> Fig. 1 is a block diagram showing the functional configuration of an analysis device that executes the analysis method of this embodiment. As shown in Fig. 1, the analysis device 1 includes a stimulation information acquisition means 11, a brain activity information acquisition means 12, and an analysis means 13. This is a specific implementation of information processing by software using hardware.

[0060] The stimulus information acquisition means 11 acquires stimulus information related to sensory stimuli. The stimulus information may be acquired by any method, for example, by having a person input numerical values or options, or by receiving information from a device that outputs sensory stimuli. The stimulus information is information related to the sensory stimuli to be given to the subject. The stimulus information preferably includes information related to the intensity and content of the stimulus according to the type of sensory stimulus (visual, auditory, tactile, taste, or olfactory).

[0061] For example, for visual stimuli, it is expected that the optical characteristics of images, light, objects, etc. shown to the subject will be acquired as stimulus information. For auditory stimuli, it is expected that the amplitude and frequency of sound, the properties of language and music, etc. will be acquired as stimulus information. For tactile stimulation, it is expected that the stimulus information to be obtained will include contact conditions such as the strength and duration of contact, whether the subject actively touched the object themselves or was passively touched, and information about the object itself, such as its mechanical properties (physical properties) such as hardness and surface characteristics, and temperature. Regarding taste stimulation, it is expected that information such as ingredients and balance of sweetness, saltiness, sourness, bitterness, and umami will be acquired as stimulation information. Regarding olfactory stimulation, it is expected that information such as chemical properties and components of the object that the subject is made to smell will be acquired as stimulation information.

[0062] The brain activity information acquisition means 12 acquires brain activity information for each of a plurality of subjects when a sensory stimulus is applied. The brain activity information is any information that indicates activity in a specific region of the brain. For example, information on brain activity acquired by any method such as fMRI, cerebral blood flow, or optical imaging is included in the brain activity information. In the present invention, the degree of activity of each region of the brain indicated by the brain activity information is referred to as the activity of that region, and an increase in activity is referred to as activation. In this embodiment, fMRI information showing brain activity in the anterior prefrontal cortex, which is a region of the brain related to secondary reward, is used as brain activity information.

[0063] The analysis means 13 analyzes the relationship between the activation of the area in the brain related to secondary reward and the sensory stimulation based on the stimulation information and the brain activity information. For example, when a tactile stimulus is given as a sensory stimulus, the analysis means 13 can perform a correlation analysis between brain activity information indicating the degree of brain activity and the physical properties of an object that is brought into contact with the subject. It is preferable that the analysis means 13 performs a correlation analysis between a plurality of physical properties and the brain activity information, and identifies physical properties that have a correlation with the brain activity information. Furthermore, for example, when an olfactory stimulus is given as a sensory stimulus, the analysis means 13 can analyze brain activity information indicating the degree of brain activity and the components contained in the object that the subject is made to smell. Specifically, for example, it is expected that the analysis means 13 will identify, through analysis, the components contained in a plurality of objects that significantly increased brain activity when the subject was made to smell the odor. Furthermore, for example, when a visual stimulus is given as a sensory stimulus, the analysis means 13 can analyze the relationship between brain activity information indicating the degree of brain activity and the characteristics of the image shown to the subject. Examples of image characteristics include characteristics related to the color, shape, etc. that make up the image.

[0064] <3. Hardware configuration> One or more information processing devices 10 (computer devices), such as a general-purpose server or a personal computer, can be used as the analysis device 1. In this embodiment, the analysis device 1 is an information processing device 10 in which a computer program (analysis program) that executes an analysis method is installed.

[0065] Fig. 2 is a hardware configuration diagram of the information processing device 10. As shown in Fig. 2, the information processing device 10 has a control unit 101, a storage unit 102, and a communication unit 103, which are used to perform the functions of each unit and each process.

[0066] The control unit 101 has a processor such as a CPU that can execute an instruction set, and executes an OS and programs. The storage unit 102 includes a volatile memory such as a RAM capable of storing an instruction set, and a non-volatile recording medium such as an HDD or SSD capable of recording an OS, an XX program, a DBMS (database server), and the like. The communication unit 103 has an interface for physically connecting to a network, and controls communication with the network NW to input and output information. The communication unit 103 also has an interface for physically connecting to any other input / output device, and controls communication with the input / output device to input and output information.

[0067] <4. Analysis method> The analytical method of the present invention will now be described in detail with reference to an example embodiment. First, an overview of the analytical procedure for analyzing the relationship between sensory stimuli and brain activity information will be provided using FIG. 3. The procedure shown here is merely an example, and the order can be changed without departing from the spirit of the method. Furthermore, the analytical method of the present invention aims to analyze the relationship between sensory stimuli and activation of brain regions related to secondary rewards and to discover patterns therein, but is not intended as a medical procedure, including treatment or diagnosis. Furthermore, in this analytical method, the sensory stimuli refer to those experienced in daily life, and do not include invasive stimuli.

[0068] First, in step S11, the stimulus information acquisition means 11 acquires stimulus information regarding a sensory stimulus to be given to a subject. Then, in step S12, the brain activity information acquisition means 12 acquires brain activity information from multiple subjects when the sensory stimulus is given. The brain activity information is obtained by measuring brain activity in areas of the brain related to secondary reward in response to the sensory stimulus. The timing of the sensory stimulus and measurement of the brain activity information may be simultaneous with the sensory stimulus, or the measurement of the brain activity information may be performed within a certain period of time after the sensory stimulus. Here, "within a certain period of time" means within a period of time during which changes in brain activity due to the sensory stimulus can be observed. The order of steps S11 and S12 may be reversed.

[0069] Steps S11 and S12 are then repeated for each subject for multiple sensory stimuli (step S13). The multiple sensory stimuli are of the same type (visual, auditory, tactile, taste, or olfactory), but each has different stimulus information indicating its specific content. This makes it possible to analyze the relationship between sensory stimuli and brain activity according to the type of sense.

[0070] When acquisition of stimulation information and brain activity information from all subjects for all sensory stimuli is completed, the process proceeds to step S14 (Y in step S13), where the analysis means 13 analyzes the relationship between the stimulation information and the brain activity information. Then, in step S15, the analysis means 13 identifies, based on the analysis result of step S14, sensory stimuli related to activation of brain activity in areas of the brain related to secondary reward as sensory stimuli that activate brain activity in those areas.

[0071] Specifically, for example, in step S12, a sensory stimulus that significantly increases the activity of a region of the brain related to secondary reward in subjects who meet or exceed a standard may be identified as a sensory stimulus that activates the brain activity of that region. Note that the standard here may be determined from any viewpoint, such as the number or percentage of subjects. Another possible method is to express multiple types of stimulation information and brain activity information as numerical values, perform a correlation analysis between them, and identify stimulation information that has a correlation with brain activity information. Alternatively, a method can be considered in which, when sensory stimulation is performed, multiple sensory stimuli that significantly increase the activity of areas of the brain related to secondary rewards in a certain number of subjects are identified, and the common elements are identified as sensory stimuli that activate the brain activity of those areas.

[0072] The analysis in step S14 may be performed for each classification of subjects based on attributes such as age group, gender, etc. For example, it is conceivable to perform the above analysis by dividing the subjects into age groups, and analyze the differences in the relationship between stimulation and brain activity depending on the age group.

[0073] In this way, by acquiring and analyzing stimulation information related to sensory stimulation and brain activity information related to brain activity when the sensory stimulation is given using any method, it is possible to clarify the relationship between the sensory stimulation and brain activity in the area of the brain related to secondary reward. Here, brain activity information is acquired from multiple subjects. In the analysis, the average or median of the multiple subjects may be used, or individual data may be considered using other methods. Note that while an example in which each step is performed by the analysis device 1 has been shown here, the present invention is not limited to this, and similar procedures may also be performed by a human, for example.

[0074] <5.Physical property analysis> Next, an example of the analysis method of the present invention will be described in detail, in which a subject is given tactile stimulation by having the subject touch a plurality of objects with different physical properties, a plurality of physical property values are obtained as stimulation information for each object the subject touches, and the relationship between the physical properties and brain activity information indicating activity in areas of the brain related to secondary reward is analyzed. Figure 4 is a flowchart showing the steps of the method for analyzing physical properties and brain activity in this embodiment. Steps S21 to S25 are an example of the steps corresponding to steps S11 to S15 in Figure 3, respectively.

[0075] In the example of Fig. 4, the physical property values of an object that is to come into contact with the subject are used as stimulus information. In step S21, the stimulus information acquisition means 11 acquires multiple types of physical property values for each of the multiple objects. Objects to be analyzed in this embodiment are objects that come into contact with a person during use, such as cosmetics, towels, clothing, and masks. Typical examples of objects to be analyzed include, but are not limited to, multiple cosmetics with different physical properties, such as creams, lotions, and oils.

[0076] The physical property to be measured can be any property measurable by a known measuring device. For example, physical property values related to friction, surface characteristics, temperature, deformation, etc. are expected. More specifically, physical property values include the static friction coefficient, the dynamic friction coefficient, the average and variance of roughness related to surface irregularities, characteristics related to the average gap, maximum height, and minimum height, a value indicating the degree of heat absorption, the temperature of the material itself, the maximum heat flux value (q-max), thermal conductivity, surface energy, temperature-related indicators such as enthalpy, Young's modulus, water content, viscoelasticity, hardness, etc.

[0077] In this embodiment, the physical properties are measured using a special test specimen, with the aim of specifically measuring contact between people and objects. As a measuring device, for example, SynTouch's Toccare tactile sensation quantification and evaluation system (hereinafter referred to as the "Toccare system") can be used (see "Technology - Quantify haptics consistently with SynTouch", URL: https: / / syntouchinc.com / technology / ).

[0078] The Toccare system uses a finger-type tactile sensor that mimics the fingers of a human hand to measure shape, movement, softness, etc., specifically the tactile sensations perceived by human fingertips. Based on the data acquired by the finger-type tactile sensor, the Toccare system acquires 15 types of physical property values for the object being measured, classified into five categories: friction, texture, adhesive, thermal, and compliance.

[0079] An example of a physical property value relating to the deformation of an object is a value indicating the degree to which the finger-type tactile sensor deforms when the finger-type tactile sensor touches the object to be measured, and the accompanying deformation of the object envelops the surface of the finger-type tactile sensor. Here, the finger-type tactile sensor is an example of a "test object" in the present invention. The test object may have any shape, but is preferably an object that deforms upon contact with the object. In particular, it is preferable to measure using a rod-shaped test object whose hardness, thickness, elasticity, and other physical properties are equivalent to those of a human finger. Other physical properties relating to the deformation of an object include values relating to the ease of deformation when pressure is applied, the speed of return after deformation, the strength of the push-back after deformation, and the maintenance of the surface shape after pressure is applied. Another example of a physical property value relating to temperature is a value relating to heat absorption. When targeting an object to be applied to human skin, etc., values relating to heat absorption during application can be used as physical properties.

[0080] In step S22, the objects whose physical properties were measured in step S21 are brought into contact with the subjects, respectively, and brain activity information at that time is acquired by brain activity information acquisition means 12. For example, with the subject in contact with the objects, brain activity of the anterior prefrontal cortex, which is the part of the brain related to secondary reward, can be acquired as brain activity information by fMRI.

[0081] Here, it is preferable that the conditions for contact between the subject and the object be consistent for all objects and subjects. Examples of contact conditions include conditions indicating whether a person actively touches an object or passively touches (is touched by) an object. Note that active contact by a person with an object is called active contact, and passive contact (being touched by an object or having another person touch an object) is called passive contact.

[0082] In addition, the contact conditions also include the intensity of contact, the duration of contact, the area of contact, and the part of the person's body that comes into contact with the object. The intensity of contact is the strength of any force related to the contact between the person and the object, such as the pressure of the contact or the magnitude of any force received from other objects, and the magnitude of the force acting between the object and a support that tries to bring the object into contact with the person. In particular, when targeting an object that is applied to human skin, specific conditions include the pressure of application, the duration of application, the amount applied, the part of the person's body to which the object is applied, and the speed at which the object is spread.

[0083] Once all data has been acquired in this manner, the process proceeds to step S24. In step S24, the analysis means 13 analyzes the relationship between each physical property value and brain activity information. For example, a correlation analysis may be performed between the physical property value and the brain activity information expressed by a numerical value. In this case, in step S25, the analysis means 13 determines that a physical property correlated with the brain activity information affects activation of brain activity in a region of the brain related to secondary reward, and that contact with an object having the physical property is a tactile stimulus that activates brain activity in a region of the brain related to secondary reward.

[0084] Alternatively, for example, for a certain physical property, multiple objects may be divided into a group with high physical property values and a group with low physical property values, and the tendency of brain activity information may be analyzed for each group. If there is a significant difference in activity represented by brain activity information between the group with high physical property values and the group with low physical property values, the analysis means 13 determines in step S25 that the physical property affects the activation of brain activity in areas related to secondary rewards.

[0085] <6.Component analysis> Next, an example of the analytical method of the present invention will be described in detail. The method involves having a subject smell a plurality of objects containing different components, thereby providing olfactory stimulation to the subject. Information about the components contained in each object is acquired as stimulation information, and the relationship between the components and brain activity information indicating activity in areas of the brain related to secondary reward is analyzed. Volatility, etc., may also be considered as stimulation information. Figure 5 is a flowchart showing the steps of the method for analyzing components and brain activity according to this embodiment. Steps S31 to S23 correspond to steps S11 to S13 in Figure 3, respectively, and step S34 corresponds to steps S14 and S15 in Figure 3.

[0086] In the example of Figure 5, the components of the object that the subject is made to smell are used as stimulus information. In step S31, the stimulus information acquisition means 11 acquires multiple types of components for each of the multiple objects. For example, a method is envisioned in which components contained in a certain amount or more for each object are identified and information on that component is acquired. Note that instead of components, scents may be classified and analyzed for each classification. The classification may be carried out by any method, but may be based on scent classifications commonly used in cosmetics, such as citrus, oakwood, vanilla, etc.

[0087] The object to be analyzed in this embodiment is an object that gives off an odor to a person when used, such as cosmetics. A plurality of cosmetics with different physical properties, such as creams, lotions, and oils, are typically considered to be objects to be analyzed, but the present invention is not limited to this.

[0088] In step S32, a plurality of subjects are made to smell each of the plurality of objects whose components have been identified in step S31, and brain activity information at that time is acquired by brain activity information acquisition means 12. For example, while the subjects are made to smell the objects, brain activity of the anterior prefrontal cortex, which is the part of the brain related to secondary reward, can be acquired as brain activity information by fMRI.

[0089] Once the contained components and brain activity information of the multiple subjects have been obtained for all the objects in this way, the process proceeds to step S34. In step S34, the analysis means 13 identifies a common contained component among the multiple objects in which brain activity in the areas related to secondary reward was observed. The analysis means 13 then determines that this common component affects the activation of brain activity in the areas related to secondary reward.

[0090] When analyzing by odor classification instead of by component, for example, trends in brain activity information may be analyzed for each odor classification. Then, an odor that significantly increases brain activity in the area related to secondary rewards compared to normal times or when smelling other odors can be identified as an olfactory stimulus that activates brain activity in that area.

[0091] <7. Design Analysis> Next, we will explain in detail an example of the analysis method of the present invention, in which visual stimulation is provided to a subject by showing the subject a number of different images, and information on the design elements that make up each image shown to the subject is obtained as stimulation information, and the relationship between brain activity information that indicates activity in areas of the brain related to secondary rewards and the design elements is analyzed.

[0092] In this embodiment, design elements that represent the characteristics of an image are used as stimulus information. Design elements are elements that represent design properties such as color and shape. Examples of design elements include shape elements such as straight / curved, monotonous / complex, flat / solid, and color elements such as cool / warm color, brightness, and saturation.

[0093] 6 is a flowchart showing the steps of the method for analyzing contained components and brain activity in this embodiment. Steps S41 to S43 correspond to steps S11 to S13 in FIG. 3, respectively, and step S44 is an example of the steps corresponding to steps S14 and S15 in FIG. 3.

[0094] In step S41, the design elements that make up the image are acquired for each of the multiple images by the stimulus information acquisition means 11. For example, a method is envisaged in which each image is evaluated from various viewpoints and an evaluation or classification for each viewpoint is acquired.

[0095] In step S42, the images for which design elements were identified in step S41 are shown to the subjects, respectively, and brain activity information at that time is acquired by brain activity information acquisition means 12. For example, while the images are shown to the subjects, brain activity of the anterior prefrontal cortex, which is the part of the brain related to secondary reward, can be acquired as brain activity information by fMRI.

[0096] Once the design elements and brain activity information of the subjects have been acquired for all images in this way, the process proceeds to step S44, where the analysis means 13 identifies components common to the images in which brain activity in areas related to secondary rewards was observed. The analysis means 13 then determines that this common component influences the activation of brain activity in areas related to secondary rewards.

[0097] It is also possible to define paired design elements in advance and compare each element. For example, one possible method would be to prepare corresponding images for the paired design elements of straight lines and curved lines, and then compare which of the straight and curved designs activates more brain activity in the areas related to secondary rewards based on brain activity information when the images are shown.

[0098] <8. Evaluation Method> As described above, it is possible to identify the physical properties and components of an object, as well as design elements that constitute visual stimuli, that activate brain activity in the area of the brain related to secondary reward. Then, by evaluating the physical properties and components, it becomes possible to appropriately evaluate the object from the perspective of the attractiveness and pleasure felt when using it. That is, another aspect of the present invention is a method for evaluating an object, and this evaluation method will be described here. The present invention can be applied, typically, to the evaluation of cosmetics, but is not limited thereto.

[0099] First, we will explain how to evaluate objects that come into contact with people during use. First, using the procedure described in <5. Physical Property Analysis>, we identify physical properties that affect brain activity in the areas of the brain related to secondary rewards (for example, physical properties that have been found to be correlated with brain activity information). For example, if there is a positive correlation between the physical property value and brain activity information (the higher the physical property value, the greater the effect of activating brain activity), the higher the physical property value, the higher the evaluation.

[0100] Next, we will explain how to evaluate products that cause people to sense a certain scent when they are used. First, we will identify the components that affect brain activity in the areas related to secondary rewards using the procedure described in <6. Component Analysis>. For example, if there is a positive correlation between the amount of a component and brain activity information (the greater the amount of a component, the greater the effect of activating brain activity), the greater the amount of the component, the higher the evaluation.

[0101] <9.Design method> The above-described evaluation method can also be used to design a product. That is, another aspect of the present invention is a method for designing a product, and the design method will be described here. The present invention can be typically applied to the design of cosmetics, but is not limited thereto.

[0102] First, we will explain how to design an object that comes into contact with a person during use. First, using the procedure described in <5. Physical Property Analysis>, identify the physical properties that affect the activity of brain activity in the area of the brain related to secondary reward (for example, physical properties that have been found to correlate with brain activity information), and then use the procedure described in <8. Evaluation Method> to evaluate the object using the physical properties as indicators. Then, based on this evaluation, the object is designed. Specifically, standard values for the physical properties are set, and the physical properties are adjusted to meet the standard values, and the object is designed.

[0103] Next, we will explain how to design products that make people smell the scent when they are used. First, using the procedure described in <6. Component Analysis>, we identify the components that affect the activity of the brain's secondary reward-related areas, and then, using the procedure described in <8. Evaluation Method>, we evaluate the product using these components as indicators. The product is then designed based on this evaluation. Specifically, standard values for the component amounts are set, and the component amounts are adjusted to meet the standard values, and the product is then designed.

[0104] Next, we will explain the design method. First, using the procedure described in <7. Design Analysis>, we identify the design elements that affect the activation of brain activity in the areas related to secondary rewards. Then, using the procedure described in <9. Evaluation Method>, we evaluate the design using the design elements as indicators. Then, we develop the design based on that evaluation.

[0105] <10. How to activate brain activity> Due to the relationship between sensory stimulation and brain activity in the areas of the brain related to secondary rewards, it is possible to activate brain activity in these areas through sensory stimulation. Below, a method for activating brain activity in the areas of the brain related to secondary rewards will be described.

[0106] The above-described analysis can identify a sensory stimulus that affects brain activity in the area of the brain related to secondary reward. Thus, another aspect of the present invention is a method for activating brain activity in the area of the brain related to secondary reward by providing the subject with the sensory stimulus (the sensory stimulus identified by the above-described analysis method).

[0107] The present invention aims to change the way a subject feels at a given time, for example, in the fields of entertainment or beauty, but does not aim at medical procedures including treatment or diagnosis. That is, the present invention is a method for enhancing the attractiveness and pleasure felt by a subject by temporarily activating brain activity in the area of the brain related to secondary reward. However, the present invention does not include acts of providing sensory stimulation to a subject for the purpose of treating or diagnosing a pathological condition. Furthermore, in the method for activating brain activity according to the present invention, the sensory stimulation refers to sensory stimulation experienced in daily life and does not include invasive stimulation.

[0108] Specifically, one aspect of the present invention is a method for activating brain activity in a region of a subject's brain related to secondary rewards by having the subject apply a cosmetic to their own skin. Here, the cosmetic is applied by the subject to provide a tactile stimulus to the subject. The tactile stimulus is a sensory stimulus that activates brain activity in a region of the brain related to secondary rewards, as identified by the above-described analysis method. That is, the cosmetic is, for example, designed by the method described in <9. Design Method> or evaluated as meeting the criteria by the method described in <8. Evaluation Method>. The present invention is not limited to cosmetics, and may also be a method for activating brain activity in a region of the brain related to secondary rewards by having the subject come into contact with such an object.

[0109] Another aspect of the present invention is a method for activating brain activity, which activates brain activity in a region of the brain related to secondary rewards by having the subject come into contact with an object having physical properties that make the subject feel comfortable when touched, wherein the object provides a tactile stimulus to the subject upon contact with the subject.

[0110] Another aspect of the present invention is a method for activating brain activity in a region of a subject's brain related to secondary reward by providing the subject with an olfactory stimulus. Here, the olfactory stimulus is provided by having the subject smell an object. The olfactory stimulus is a sensory stimulus that activates brain activity in a region of the brain related to secondary reward, as identified by the above-described analysis method. That is, the object is, for example, designed by the method described in <8. Design Method> or evaluated as meeting the criteria by the method described in <7. Evaluation Method>. For example, a cosmetic product can be used as such an object.

[0111] Another aspect of the present invention is a method for activating brain activity in a region of the brain associated with secondary reward by providing a visual stimulus to the subject. The visual stimulus is provided, for example, by showing the subject an image. The visual stimulus is a sensory stimulus that activates brain activity in the region of the brain associated with secondary reward, as identified by the above-described analysis method. For example, the visual stimulus may be a multicolored visual stimulus or a visual stimulus showing a three-dimensional shape, such as showing the subject an image containing design elements showing a multicolored or three-dimensional shape.

[0112] As described above, according to the present invention, it is possible to analyze sensory stimuli that affect brain activity in the brain region related to secondary rewards. Furthermore, based on the results of this analysis, it is possible to evaluate and design products. Furthermore, it is possible to activate brain activity in the brain region related to secondary rewards using the sensory stimuli. By activating brain activity in the brain region related to secondary rewards, it is possible to change how a subject feels about a sensory stimulus. This allows for the analysis, evaluation, design, etc. of products from a perspective not previously available, in which, for example, sensory stimuli received during use of an item can change the impression or feeling toward the item.

[0113] <11. How to change sensation> Furthermore, through extensive research, the present inventors have discovered that there is a relationship between activation of brain activity in areas of the brain related to secondary reward and how one feels in response to sensory stimuli. Based on the above findings, a further objective of the present invention is to change how people feel about sensory stimuli by activating brain activity related to secondary rewards.

[0114] That is, one aspect of the present invention is a method for changing a subject's perception of sensory stimuli by activating brain activity in the area of the subject's brain related to secondary rewards using the procedure described above in <9. Method for activating brain activity>.

[0115] Because of the relationship between activation of brain activity in the area of the brain related to secondary rewards and how one feels about sensory stimuli, activating brain activity in that area can change how one feels about them. Also, as mentioned above, because sensory stimulation can activate brain activity in that area, performing sensory stimulation can change how one feels about other sensory stimuli.

[0116] The present invention aims to change the way a subject feels at a given time, for example, in the fields of entertainment or beauty, but does not aim at medical procedures including treatment or diagnosis. That is, the present invention is a method for enhancing the attractiveness and pleasure felt by a subject by temporarily activating brain activity in the area of the brain related to secondary reward. However, the present invention does not include acts of providing sensory stimulation to a subject for the purpose of treating or diagnosing a pathological condition. Furthermore, in the method for activating brain activity according to the present invention, the sensory stimulation refers to sensory stimulation experienced in daily life and does not include invasive stimulation.

[0117] Specifically, one aspect of the present invention is a method for changing a subject's perception of other sensory stimuli (other than tactile stimuli caused by application of the cosmetic) by having the subject apply a cosmetic to their own skin. Here, the cosmetic is applied to the subject's own skin by the subject, thereby providing the subject with a tactile stimulus. The tactile stimulus is a sensory stimulus that activates brain activity in the area of the brain related to secondary reward, as identified by the above-described analysis method. That is, the cosmetic is, for example, designed by the method described in <9. Design Method> or evaluated as meeting the criteria by the method described in <8. Evaluation Method>. The present invention is not limited to cosmetics, and may also be a method for activating brain activity in the area of the brain related to secondary reward by having the subject come into contact with such an object.

[0118] Another aspect of the present invention is a method for changing a subject's perception of other sensory stimuli (other than the tactile stimulus produced by contact with the object) by bringing the subject into contact with an object having physical properties that make the subject feel comfortable when touched, where the object produces a tactile stimulus to the subject when it comes into contact with the subject.

[0119] Another aspect of the present invention is a method for changing a subject's perception of other sensory stimuli (other than the olfactory stimulus) by providing the subject with an olfactory stimulus. Here, the olfactory stimulus is provided by having the subject smell the scent of an object. The olfactory stimulus is a sensory stimulus that activates brain activity in the area of the brain related to secondary reward, as identified by the above-described analysis method. That is, the object is, for example, designed by the method described in <8. Design Method> or evaluated as meeting the criteria by the method described in <7. Evaluation Method>. For example, a cosmetic product can be used as such an object.

[0120] Another aspect of the present invention is a method for changing a subject's perception of other sensory stimuli (other than the visual stimulus) by providing the subject with a visual stimulus. The visual stimulus is provided by showing an image or an object. The visual stimulus is a sensory stimulus that activates brain activity in the brain region related to secondary reward, as identified by the above-described analysis method. That is, the visual stimulus is an object or image that includes design elements that activate brain activity in the brain region related to secondary reward. Examples of such design elements include multicolored or three-dimensional shapes. [Example]

[0121] The present inventors have conducted experiments to examine the relationship between sensory stimulation and activation of brain activity. The following examples are merely examples, and it goes without saying that the present invention is not limited to the following examples. In this example, activation of the brain region related to secondary reward by sensory stimulation was confirmed in multiple subjects.

[0122] (1) Experimental procedure In this example, tactile stimulation was used as the sensory stimulation. Specifically, the skin care product was dropped onto the outer side of the subject's left forearm, and the subject spread the product on the subject, providing the subject with tactile stimulation. The subject's application speed was set to 3 cm / sec, as in previous studies, and the subject was trained in advance to apply a pressure of 0.5 to 1.0 N before the test.

[0123] Brain imaging was also performed to show brain activity while each subject was applying the skincare product. After applying the skincare product, each subject rated their impressions of the entire tactile vocabulary. The order of presentation of the skincare products and tactile vocabulary was randomized and counterbalanced across subjects.

[0124] (2) Analysis results Under the above conditions, brain images were taken for several skin care products with different physical properties, and brain activity in the anterior prefrontal cortex was compared. The results showed that for certain physical properties, significant differences were found in the activation of brain activity in the anterior prefrontal cortex depending on the physical property value. More specifically, skin care products with low values of the physical property related to deformation, particularly cDP, which indicates the speed at which an object returns to its original shape after deformation, were found to have a greater activation effect on brain activity in the anterior prefrontal cortex than skin care products with high values of the physical property cDP.

[0125] These results indicate that sensory stimulation activates brain activity in the anterior prefrontal cortex. [Example]

[0126] Next, an example of an experiment conducted by the present inventors to examine the relationship between brain activity and how sensory stimuli are perceived will be described. In this example, the relationship between activation of brain activity in the anterior prefrontal cortex of the brain related to secondary rewards and attractiveness ratings of tactile stimuli was investigated.

[0127] (1) Activation of brain activity through brain stimulation In this study, brain stimulation was performed to compare the tactile impression evaluations of subjects with and without activation of the anterior prefrontal cortex. Transcranial magnetic stimulation (TMS) was used. A transcranial magnetic stimulator (DuoMAG XT 100, DEYMED Diagnostic sro, Czechia) and a liquid-cooled coil (DM 70 BF LQC, DEYMED Diagnostic sro, Czechia) were used for brain stimulation.

[0128] During brain stimulation, the subject's head was fixed and the target brain area was precisely positioned. A magnetic stimulation navigation system (Brainsight Rogue Research, Inc., Canada) was used to fix the subject's head and align the target brain area.

[0129] The brain stimulation conditions were the intermittent theta burst stimulation (iTBS) protocol described by Huang et al., which consisted of 2-second theta burst stimulation followed by an 8-second pause, delivering a total of 600 pulses. Specifically, a figure-of-eight coil was placed tangentially to the head, with its center positioned over the left anterior prefrontal cortex, while a sham stimulation control was performed with a figure-of-eight coil positioned perpendicular to the head, tilted 90 degrees, and part of the coil positioned over the left anterior prefrontal cortex. The iTBS condition (activating stimulation) and the Sham condition (sham stimulation) were applied in random order and counterbalanced between subjects.

[0130] The interval between each condition was set to 60 minutes, based on reports that the excitatory effects of iTBS last up to 60 minutes after stimulation (Huang, YZ, Edwards, MJ, Rounis, E., Bhatia, KP, & Rothwell, JC (2005), Theta Burst Stimulation of the Human Motor Cortex. Neuron, 45(2), 201-206). After magnetic stimulation of the left anterior prefrontal cortex, a tactile evaluation test was conducted within the duration of the stimulation effect.

[0131] (2) Texture evaluation Each subject underwent brain stimulation of the left anterior prefrontal cortex under either iTBS (activating stimulation) or sham (sham stimulation) conditions. After each stimulation, the subject touched several skin care products within the duration of the stimulation effect, and the subject evaluated their subjective tactile sensation. For the tactile sensation evaluation, 0.2 g of each skin care product was placed in the center of an artificial leather bag placed in a black box. Subjects were asked to touch the product with the pad of their index finger without being able to see their hands, and then evaluate their impressions. A 19-word tactile vocabulary was used to describe the tactile sensation, and these tactile vocabulary words were used to evaluate the sensation using a visual analogue scale (VAS). Each response was converted to a numerical value from 0 to 100 and used for analysis.

[0132] Based on the tactile evaluations by multiple subjects, attractiveness ratings for each skin care product were calculated under both the iTBS condition (activating stimulation) and the Sham condition (sham stimulation). For skin care products with high attractiveness ratings to begin with, the improvement in attractiveness due to stimulation is unlikely to be evident. Therefore, the following analysis focused on skin care products with attractiveness ratings below a predetermined standard under the Sham condition (sham stimulation).

[0133] (3) Overall analysis The attractiveness ratings of the target skin care products were compared under the iTBS condition (activating stimulus) and the sham condition (fake stimulus). Figure 7 shows the analysis results. The attractiveness ratings were significantly higher under the iTBS condition than under the sham condition. (**: P<0.01, n=73, Mann-Whitney U test, means±SE)

[0134] These results suggest that activating the areas of the subject's brain related to secondary reward can change (increase) the level of attraction the subject feels for the same tactile stimulus.

[0135] (4) Age group comparison Next, the subjects were divided into young and elderly groups based on age, and changes in attractiveness ratings were compared. Specifically, the differences in attractiveness ratings between the iTBS condition (activating stimulus) and the Sham condition (sham stimulus) for the same subjects were analyzed for the young and elderly groups for the multiple skin care products in question.

[0136] Figure 8 shows the analysis results showing the difference in attractiveness ratings between the young and elderly groups under the iTBS condition (activating stimuli) and the Sham condition (false stimuli). As shown above, under the same stimulation conditions, the elderly group showed a greater effect of improving attractiveness ratings for tactile stimuli than the young group. These results suggest that the relationship between activation of the anterior prefrontal cortex and attractiveness ratings for sensory stimuli may differ depending on age. [Example]

[0137] Next, we will explain an example of an experiment that investigated the relationship between activation of brain activity in the anterior prefrontal cortex related to secondary rewards and attractiveness ratings of visual stimuli. The method of brain activation by brain stimulation is the same as in Example 2, so we will not explain it here.

[0138] (1) Visual evaluation For each subject, brain stimulation was administered to the left anterior prefrontal cortex under either iTBS (activating stimulation) or Sham (sham stimulation) conditions. Afterwards, multiple images were presented to the subject within the duration of the stimulation effect, and the subject rated each image for its subjective attractiveness. In this example, a plurality of images of two types, human face images and landscape images, were prepared, and each was evaluated by subjects.

[0139] In the evaluation of the images, the distance between the display and the subject was adjusted, and the fixation point was displayed for 1000 msec, after which the image was displayed on the display for 1000 msec. Each subject was asked to rate the attractiveness of the faces or landscapes shown in the images on a 6-point scale ranging from "1" (not attractive) to "6" (attractive). Each subject was asked to perform 80 trials after each brain stimulation, for a total of 160 trials.

[0140] The facial images were presented in a random order, taking into account the age of the model. The landscape images were presented in a random order, taking into account the season depicted in the landscape images.

[0141] Based on the evaluations by multiple subjects, attractiveness ratings for each image were calculated under both the iTBS condition (activating stimulus) and the Sham condition (sham stimulus).

[0142] (2) Facial image analysis results We compared the attractiveness ratings of multiple face images under the iTBS condition (activating stimulus) and the Sham condition (sham stimulus). Figure 9(a) shows the analysis results for face images with relatively high average attractiveness ratings. As shown, attractiveness ratings were significantly higher under the iTBS condition than under the Sham condition (*: P<0.05, n=40, paired t test, means ± SE). The mean attractiveness rating was the average of the attractiveness ratings in the iTBS stimulation condition (activating stimulation) and the Sham condition (sham stimulation).

[0143] (3) Landscape image analysis results We compared the attractiveness ratings of multiple landscape images under the iTBS condition (activating stimulus) and the Sham condition (sham stimulus). Figure 9(b) shows the analysis results. As shown, for landscape images overall, attractiveness ratings were significantly higher under the iTBS condition than under the Sham condition. (**: P<0.01, n=80, paired t test, means±SE)

[0144] These results suggest that activating the areas of the subject's brain related to secondary rewards can change (increase) the degree of attraction that the subject feels toward the same visual stimulus. [Example]

[0145] Next, an example of an experiment conducted by the present inventors to examine the relationship between tactile stimuli and visual impression evaluation will be described. In this example, the relationship between tactile stimuli and attractiveness ratings for visual stimuli (images) was examined.

[0146] (1) Subjects The subjects were 16 Japanese women aged 20 to 59, with the age groups evenly distributed.

[0147] (2) Tactile stimulation Of the skin care products used in Example 1, two types were used, one with a high cDP value and one with a low cDP value. The method of applying stimulation was the same as in Example 1.

[0148] (3) Evaluation target image As the subjects of impression evaluation, human face images and landscape images were used. The facial images were taken from 80 Japanese women aged 20 to 69, photographed from the front under a constant lighting environment. The display size of the facial images was set to the width of the entire face, which could be judged in central vision at a viewing distance of 1015 mm on an 8K 32-inch display used in the experiment, within an 8° visual angle. The facial images were positioned in the center of the screen.

[0149] The landscape images consisted of 80 images of Japanese landscapes, with an equal distribution of urban and natural landscapes. For the natural landscapes, images of spring, summer, autumn, and winter were distributed equally. The display size of the landscape images had a standard angle of view of 16:9 (7680 x 4320 pixels), and the resolution of all images was made uniform by adjusting the horizontal and vertical widths to match the standard angle of view. The landscape images were then positioned in the center of the screen.

[0150] (4) Impression evaluation First, for the impression evaluation of the facial images, a fixation point was displayed for 1000 msec, followed by a facial image of the created model on the display for 1000 msec. Each subject was presented with the facial image of each model and asked to rate the attractiveness of the face on a 6-point scale ranging from "1: Not attractive" to "6: Attractive." Each subject was given 80 trials before the tactile stimulation and 80 trials after each tactile stimulation (application of skin care products), for a total of 240 trials. The order of the presented facial images was randomized.

[0151] The impression evaluation of the landscape images was conducted under the same test conditions as the impression evaluation of the model face images, except for the stimulus presentation conditions. The order of the landscape images presented was random. The viewing distance between the subject and the display presenting the model face images and landscape images was set to 1015 mm. The display presenting the model face images and landscape images was an 8K 32-inch display.

[0152] (5) Analysis results The difference in impression evaluation scores between the two conditions of tactile stimulation with a low-cDP skin care product and that with a high-cDP skin care product was calculated compared to the condition without tactile stimulation, and the impression evaluation scores for facial images and landscape images were compared. Figure 10 shows the results of an analysis of impression evaluation scores by multiple subjects for facial images and landscape images. As shown, for both facial images and landscape images, the impression evaluation scores were higher under the condition of stimulation with a low-cDP skin care product than under the condition of stimulation with a high-cDP skin care product (*: p<0.05, N=80, Mann-Whitney U-test, means±SE).

[0153] As described in Example 1, tactile stimulation with a skin care product with a low cDP significantly increased brain activity in the anterior prefrontal cortex compared to stimulation with a skin care product with a high cDP. Therefore, the results shown in Figure 10 suggest that visual impression evaluation of facial images was significantly improved by exposure to a skin care product that more effectively induces activation of the anterior prefrontal cortex. [Example]

[0154] Next, an example of an experiment investigating the relationship between visual stimulation and activation of brain activity in the anterior prefrontal cortex will be described. The subjects were subjected to the same conditions as in Example 4.

[0155] (1) Visual stimulation The stimulus images were square images with a uniform background color. The stimulus images had different characteristics in terms of color and three-dimensionality, and included 20 monochromatic and 20 multicolored images, as well as 20 images with three-dimensional designs and 20 images with flat designs. The distance between the subject's eyes and the display was 1130 mm. The image size was adjusted so that it would fit within the central field at that viewing distance.

[0156] (2) Experimental Procedure Stimulus images with different image features were divided into monochromatic and multicolored, and three-dimensional and two-dimensional. Each group was randomly presented to the subjects in order. Subjects were asked to rate each image as "aesthetic" or "unaesthetic" while brain activity was measured using fMRI. As a control, each group also underwent 10 trials of judging the direction of an arrow (lower-order thinking) without the visual stimulus. Therefore, each group underwent 40 trials of rating the images and 10 trials of the control, for a total of 50 trials, randomly assigned.

[0157] Each trial began with a fixation point displayed in the center of the screen for 3,500–6,500 ms. This variation in the duration of the fixation point before the stimulus image was presented is called jittering, and is used to increase the efficiency of separating brain responses to each image. Next, the task (either "aesthetic judgment" or "arrow direction judgment") was displayed for 1,500 ms. A design image was then displayed for 2,500 ms, and participants were asked to respond to the task while the image was displayed. Responses to the task were evaluated using a button-type response pad (consisting of two buttons for one hand) placed under the subject's right hand. The subjects practiced the "aesthetic judgment" and "arrow direction judgment" tasks using the buttons until they became familiar with them before the actual test.

[0158] (3) Analysis results We compared the differences in brain activity in the anterior prefrontal cortex when visual stimuli of each design image were presented. Significance tests were performed using the small volume correction (SVC) test, with no correction for multiple comparisons, and a significance level of p<0.005.

[0159] The analysis results are shown in Figure 11. Figure 11(a) is an image showing the difference in brain activity between when subjects were shown a monochromatic image and when they were shown a multicolored image. In the area marked with a triangle (corresponding to the anterior prefrontal cortex), brain activity was greater when subjects were shown a multicolored image than when they were shown a monochromatic image.

[0160] Figure 11(b) shows the difference in brain activity between when subjects were shown images containing a three-dimensional design and when they were shown images containing a flat design. In the area marked with a triangle (corresponding to the anterior prefrontal cortex), brain activity was greater when subjects were shown images containing a three-dimensional design compared to when they were shown images containing a flat design. [Example]

[0161] Next, an example of an experiment conducted by the present inventors to examine the relationship between visual stimulation and impression evaluation of arousal level will be described. The subjects were subjected to the same conditions as in Examples 4 and 5. The visual stimulation (stimulating images) was also subjected to the same conditions as in Example 5.

[0162] (1) Experimental procedure The stimulus images, which had different image features, were divided into single-color and multi-color, and three-dimensional and two-dimensional, and each group was randomly presented to the subjects in order. Each design condition contained 20 images, so the subjects were asked to evaluate 40 images in each group.

[0163] In each trial, a fixation point was first displayed in the center of the screen for 1000 ms to draw attention to the location of the next design image. Next, a stimulus image was displayed for 2500 ms. The subjects were then asked to evaluate the image that was displayed. The question was, "On the emotional state axis of calm-arousal, what emotional state did you experience?" There was no time limit for answering the question. Next, a blank screen was displayed for 500 ms, and subjects were asked to press the space bar to proceed to the evaluation of the next image. Note that practice evaluation using a keyboard was conducted before the actual test until the subjects became accustomed to it.

[0164] (2) Analysis results When visual stimuli of the spatial design were presented, each subject was asked to provide an impression rating of their level of arousal, and the impression ratings were compared between each stimulus condition. Significance tests were performed using the Wilcoxon signed rank sum test, with a significance level of p<0.05.

[0165] Figure 12 shows the results of an analysis comparing the changes in impression evaluation values of arousal level under stimulation conditions based on pairs of design elements (monochrome vs. multicolor, flat vs. three-dimensional). These results show that multicolor increases arousal level more than monochrome, and three-dimensionality increases arousal level more than flatness. [Explanation of symbols]

[0166] 1:Analyzer 11: Stimulus information acquisition means 12:Means for acquiring brain activity information 13: Analysis means 10: Information processing device 101: Control unit 102: Storage section 103: Communications Department

Claims

1. an acquisition step of acquiring measurement results of brain activity of a region of the brain of the subject related to secondary reward when the subject receives a sensory stimulus; an analysis step of performing the acquisition step for each of a plurality of types of sensory stimuli on a plurality of subjects and analyzing the relationship between the activation of the region and the sensory stimuli through statistical analysis; A method for analyzing sensory stimuli that activate brain activity in the area, comprising:

2. The analysis method according to claim 1 , wherein the region is the anterior prefrontal cortex.

3. The analysis method according to claim 1 or 2, wherein the sensory stimulus includes a tactile stimulus.

4. The analysis method according to claim 3 , wherein the tactile stimulus is given to the subject by bringing the subject into contact with an object.

5. The product is a cosmetic, The analysis method according to claim 4 , wherein the tactile stimulus is given to the subject by the subject applying the cosmetic to his or her own skin.

6. the plurality of sensory stimuli are given to the subject by bringing the subject into contact with a plurality of objects having different physical properties, respectively; The analysis method according to claim 4 , wherein the analyzing step includes a step of performing a correlation analysis between the brain activity and the physical property, and identifying the physical property that has a correlation with the brain activity.

7. The analysis method according to claim 1 or 2, wherein the sensory stimulus includes an olfactory stimulus.

8. the plurality of sensory stimuli are given to the subject by having the subject smell a plurality of odors of substances each containing a different component; The analysis method according to claim 7 , wherein the analyzing step includes a step of identifying a component commonly contained in the substances that have the effect of activating the brain activity.

9. The analysis method according to claim 1 or 2, wherein the sensory stimulus includes a visual stimulus.

10. The plurality of sensory stimuli are given to the subject by presenting a plurality of images each having a different design element to the subject, The analysis method according to claim 9 , wherein the analyzing step includes a step of identifying design elements that are commonly contained in the images that have the effect of activating the brain activity.

11. The analysis method according to claim 1 , wherein the analyzing step includes a step of performing the statistical analysis for each age group of the subjects.

12. A method for evaluating cosmetics, comprising evaluating the cosmetics using the physical property determined by the analytical method according to claim 6 as an index.

13. A method for evaluating cosmetics, comprising evaluating the cosmetics using the components identified by the analytical method according to claim 8 as indicators.

14. an evaluation step of evaluating a cosmetic product using the physical property identified by the analysis method according to claim 6 as an index; and a design step of adjusting the physical properties of the cosmetic based on the evaluation.

15. an evaluation step of evaluating a cosmetic product using the component identified by the analysis method according to claim 8 as an index; and a design step of adjusting the amounts of the ingredients based on the evaluation.

16. A method for activating brain activity (excluding medical procedures), in which a subject applies a cosmetic to their skin, thereby activating brain activity in the area of the subject's brain related to secondary rewards.

17. A method of activating brain activity (excluding medical procedures) in which brain activity in the area of a subject's brain related to secondary rewards is activated by having the subject come into contact with an object that has physical properties that make the subject feel comfortable when touched.

18. 18. The method for activating brain activity according to claim 17 (excluding medical procedures), wherein the physical property is a property relating to deformation of the object when a test specimen comes into contact with the object.

19. A method for activating brain activity (excluding medical procedures), which activates brain activity in areas of the subject's brain related to secondary reward by providing the subject with olfactory stimulation.

20. A method for activating brain activity (excluding medical procedures), which activates brain activity in areas of the subject's brain related to secondary reward by providing the subject with visual stimuli.

21. The method for changing sensations according to claim 20 , wherein the visual stimulus includes a stimulus expressed in multiple colors.

22. The method for changing sensations according to claim 20 , wherein the visual stimulus includes a stimulus showing a three-dimensional shape.

23. A method for activating brain activity (excluding medical procedures) in which sensory stimuli are determined based on the age of the subject, and the sensory stimuli are given to the subject, thereby activating brain activity in the area of the subject's brain related to secondary rewards.

24. 24. The method for activating brain activity according to claim 16, wherein the region is the anterior prefrontal cortex.

25. A method for changing sensations in which a subject is given a sensory stimulus to change the way the subject feels about other sensory stimuli.

26. the sensory stimulus comprises a tactile stimulus; The sensation changing method according to claim 25, wherein the tactile stimulus is given by bringing the subject into contact with an object having physical properties that make the subject feel comfortable when touched.

27. The method for changing sensations according to claim 25, wherein the sensory stimulation to be given to the subject is determined based on the age of the subject.

28. 26. The method of claim 25, wherein the sensory stimulus comprises an olfactory stimulus.

29. 26. The method of claim 25, wherein the sensory stimulus comprises a visual stimulus.

30. 30. The method of claim 29, wherein the visual stimulus includes a stimulus expressed in multiple colors.

31. 30. The method for changing sensations according to claim 29, wherein the visual stimulus includes a stimulus showing a three-dimensional shape.

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