Mental imagery-based neurofeedback to improve cognitive function

Abstract

Neurofeedback training may include having a subject visualizing a mental imagery have neural signals recorded using scalp electrodes that quantify visual working memory related to the mental imagery. The subject's performance on visualization may be scored based on neural activity related to cognitive function within the neural signals during an induction period. Feedback may be provided to the subject based on the score to inform the subject of a success rate with respect to the visual working memory. A goal of the neurofeedback training may be to improve the subject's cognitive function.

Description

Detailed Description of the Invention

[0001] (Related Applications) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 220,646, entitled "MENTAL IMAGE-BASED NEUROFEEDBACK TO IMPROVE COGNITIVE FUNCTION," filed July 12, 2021, the subject matter of which is incorporated herein by reference in its entirety.

[0002] (Government support) This invention was made with government support under Grant Nos. R01EY019466 and R01EY027841 awarded by the National Institutes of Health, Grant No. BSF 2016058 awarded by the U.S.-Israel Binational Science Foundation, and Grant No. JPMJCE1311 awarded by the Science and Technology Agency of Japan. The governments of the United States, Israel, and Japan have certain rights in this invention. [Technical Field]

[0003] The present disclosure relates generally to neurofeedback, and more particularly to an improvement system and method for providing neurofeedback based on neural signals associated with mental imagery to improve at least one cognitive function. [Background technology]

[0004] Neurofeedback can be used to modify brain function and configuration through operant conditioning by measuring brain activity in real time and providing feedback to the user. Neurofeedback training has been employed to reduce symptoms of specific cognitive disorders (e.g., attention deficit hyperactivity disorder (ADHD), depression, anxiety, traumatic brain injury, stroke, epilepsy, etc.) and to improve cognitive function (e.g., visual attention, working memory, concentration, short-term memory, emotion, creativity, etc.) in patients with cognitive impairments. Neurofeedback training has recently attracted attention. In particular, gameplay has been touted as a simple way to improve cognitive abilities. However, extended training on tasks using gameplay or other simple neurofeedback techniques has been shown to only improve performance on the trained tasks, rather than reliably improving cognitive functions that generalize to basic higher-order cognitive functions. Summary of the Invention

[0005] As an alternative to behavioral training techniques (such as gameplay and other simple neurofeedback techniques) that do not improve cognitive functions that generalize to basic higher-order cognitive functions, the present disclosure provides systems and methods that employ neurofeedback techniques that reliably improve cognitive functions that generalize to basic higher-order cognitive functions. The neurofeedback techniques provided by the present invention involve the user imagining (or mentalizing) a mental image, attempting to improve a previous score based on the mental image, and providing a new score based on the mental image.

[0006] A system may be configured to have a subject participate in a neurofeedback training trial. The system includes a memory storing instructions and a processor. The processor is configured to access the memory and execute the instructions to receive neural signals from a plurality of scalp electrodes quantifying visual working memory related to mental imagery, score the subject's performance based on neural activity related to cognitive function during an induction period in the neural signals, and provide feedback to the subject based on the score to inform the subject of a success rate for the visual working memory. After the trial, the cognitive function of the subject is improved.

[0007] A method for neurofeedback training can improve a subject's cognitive function. The method includes having the subject participate in neurofeedback training for a certain period of time. During each test period of the neurofeedback training, neural signals quantifying visual working memory related to mental imagery are recorded using scalp electrodes, and the subject's performance is scored based on neural activity related to cognitive function during an induction period within the neural signals. Feedback is provided to the subject based on the score to inform the subject of the success rate of the visual working memory. After the certain period of time, the subject's cognitive function is improved.

[0008] The foregoing and other features of the present disclosure will become apparent to those skilled in the art after reading the following description in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram of an exemplary system for providing neurofeedback based on neural signals related to mental imagery to improve cognitive function. [Figure 2] 2A-2C illustrate different periods of neurofeedback training performed by the system of FIG. 1. [Figure 3] FIG. 1 is a process flow diagram of a method for conducting a single trial of neurofeedback training as described herein. [Figure 4] FIG. 4 is a process flow diagram of a method for providing a score for the test of FIG. 3. [Figure 5] Shown are scalpographies of the CDA channel and the corresponding feedback scores for each group. [Figure 6] FIG. 1 is a schematic diagram of a neurofeedback training trial. [Figure 7] 1 is a flowchart illustrating a process for calculating a workflow in real time. [Figure 8] Scalp graphs of averaged ERPs within 400-1000 ms and 1000-5000 ms after go signal onset are shown, with grey circles indicating the target channel of interest. [Figure 9] The grand average hemispheric difference ERP waveforms (left hemisphere - right hemisphere electrodes) for each group within 400-1000 ms and 1000-5000 ms are shown. [Figure 10] Grand mean hemispheric difference amplitudes for CDA channels within training sessions (days 1-5) are shown. [Figure 11] Attention efficiency scores and visual working memory scores before and after training are shown. [Figure 12] We show that working memory gains are related to the degree of left-sided CDA, whereas behavioral changes are not related to the degree of right-sided CDA. DETAILED DESCRIPTION OF THE INVENTION

[0010] I. Definition Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0011] As used herein, the singular forms "a", "an" and "said" can include the plural forms as well, unless the context clearly dictates otherwise.

[0012] As used herein, the technical terms "comprise" and / or "contain" may specify the presence of stated features, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components and / or groups.

[0013] As used herein, the term "and / or" may include any and all combinations of one or more of the associated listed items.

[0014] As used herein, terms such as "first," "second," and the like, do not limit the elements described by these terms. These terms are used only to distinguish one element from another. Thus, a "first" element described below could also be referred to as a "second" element without departing from the teachings of the present disclosure. The order of operations (or actions / steps) is not limited to the order presented in the claims or drawings unless otherwise specified.

[0015] As used herein, the technical term "neurofeedback" may refer to a form of biofeedback in which a user responds, typically in real time, to feedback of brain activity (eg, sensory feedback).

[0016] As used herein, the technical term "neurofeedback training" may refer to the use of neurofeedback to modify brain function or configuration through operant conditioning. Operant conditioning may be based on feedback (e.g., sensory feedback) that promotes self-regulation. For example, neurofeedback training has been employed to reduce symptoms of certain disorders (e.g., ADHD, depression, anxiety, traumatic brain injury, stroke, epilepsy, etc.) and improve cognitive function.

[0017] As used herein, the technical term "cognitive function" is a broad term and may refer to mental processes involved in knowledge acquisition, information manipulation, and reasoning. Cognitive function may include visual attention, working memory (also called visual working memory), concentration, short-term memory, emotion, creativity, etc.

[0018] As used herein, terms of art such as "mental imagery," "mental picture," and "mental imagination" may refer to sensory experiences that may be similar to the experience of perceiving an object, event, and / or scene, but that occur when the relevant object, event, or scene is not actually present to the senses. In other words, mental images can be "imagined," "created," "mentalized," etc., with or without effort.

[0019] As used herein, terms of art such as "user," "participant," "subject," and the like may refer to any human being who participates in or seeks to participate in neurofeedback training.

[0020] As used herein, the technical term "controller" may refer to anyone performing neurofeedback training and may include one or more computing devices and / or a human performing the neurofeedback training.

[0021] As used herein, the technical term "real-time" may refer to the time that feedback is available after an event. In some cases, feedback may be real-time if it is available within 10 seconds after an event. In other cases, feedback may be real-time if it is available within 5 seconds after an event. In many other cases, feedback may be real-time if it occurs within 1 second after an event. In many other cases, feedback may be real-time if it occurs within 50 milliseconds after an event.

[0022] II. Overview Traditionally, gameplay and other simple neurofeedback techniques have been promoted as treatments that can improve cognitive function. However, gameplay and other simple neurofeedback techniques have been shown to be unable to reliably improve cognitive function or generalize to higher-order cognitive functions. As an alternative to gameplay and other simple neurofeedback techniques, the present disclosure provides a system and method for improving cognitive function by employing a neurofeedback technique based on user-generated mental imagery. The neurofeedback technique described herein improves one or more cognitive functions by utilizing the human ability to learn and accumulate statistical experience. In particular, the neurofeedback technique includes one or more tests, recording neural signals quantifying visual working memory related to mental imagery using scalp electrodes (worn by the user undergoing neurofeedback training), scoring the user's performance based on neural activity related to cognitive function during an induction period in the neural signals, and providing feedback to the user based on the score to inform the subject of their success rate regarding visual working memory. The user aims to improve their scores across different tests. After one or more tests, cognitive function is improved.

[0023] III.System One aspect of the present disclosure may include a system 10 (FIG. 1) that can provide neurofeedback based on neural signals related to a user forming a mental image. The mental image may be created / formed by the user without being prompted as to what to imagine. For example, the mental image may be based on a memory specific to the user. The mental image may, but need not, be different for different users and / or for different neurofeedback training trials. For example, one user may form a mental image of an auditory sound (e.g., hearing their mother's voice), while another user may form a visual mental image of a sunny day at the beach. In other words, the specific mental image is not important; the fact that the user is creating a mental image is the subject of the neurofeedback. The neurofeedback provided by the system of FIG. 1 has been shown to improve one or more cognitive functions and is superior to neurofeedback provided by gameplay and other simple neurofeedback techniques, which have been shown not to reliably improve cognitive functions.

[0024] A user participates in neurofeedback training, which may include one or more trials, using the system of Figure 1. Although system 10 is described for performing a single neurofeedback training trial, it should be understood that system 10 can be used to conduct one or more neurofeedback training trials (e.g., as described in the Experimental Section below).

[0025] The system 10 may include scalp electrodes 12, a display 14, and one or more computing devices 16. The scalp electrodes 12 may be connected to one or more computing devices 16 via an input / output port (I / O1) 18, while the display 14 may be connected to one or more computing devices 16 via another input / output port (I / O2) 22. Each of the input / output ports 18, 22 may include circuitry (which may be the same or different for different ports) configured to facilitate data communication / transfer between the one or more computing devices 16 and a device (e.g., the scalp electrodes 12 or the display 14) connected to the corresponding input / output port. Additionally, each of the corresponding input / output ports may be configured for wired and / or wireless communication. It should be understood that one or more computing devices 16 may have more than two ports.

[0026] The scalp electrodes 12 may be configured to be placed or positioned at predetermined locations on the subject's scalp to record neural signals. The scalp electrodes 12 may be active and / or passive electrodes. By way of example, the scalp electrodes 12 may be EEG electrodes (e.g., traditional wet Ag / AgCl electrodes, active dry-wet single gold pin-based electrodes, hybrid dry multiple spike-based electrodes, passive dry solid gel-based electrodes, etc.). A comprehensive standard EEG analysis uses as many as 64 electrodes. The system 10 may use as many as 64 scalp electrodes 12, or alternatively, may utilize only a subset of traditionally used EEG electrodes (e.g., utilizing only posterior-parietal and / or occipital EEG electrodes). Each of the scalp electrodes 12 may be associated with a channel (e.g., the scalp electrodes may include electrodes positioned at the occipital region associated with one or more posterior-parietal channels and / or electrodes positioned near the occipital region associated with one or more occipital channels). As an example, in some cases, neural signals may be measured from at least one of one or more posterior parietal channels and / or at least one of one or more occipital channels. The scalp electrodes 12 may transmit the neural signals to one or more computing devices 16 via one or more channels connected to the input / output port (I / O1) 18. It should be understood that one or more additional components associated with the computing device 16 and / or the scalp electrodes 12 may perform pre-processing tasks on the neural signals recorded by the scalp electrodes 12.

[0027] The display 14 can provide visual, auditory, tactile, and / or other signals to the user during neurofeedback training. The display 14 can include a monitor (e.g., capable of providing visual stimuli), a speaker (e.g., capable of providing auditory stimuli), and / or different peripheral devices (e.g., capable of providing tactile stimuli). For example, the display 14 can display instructions for the user to start and / or stop a neurofeedback training test, or feedback such as a score on a neurofeedback training test. The display 14 can send and receive data to and from one or more computing devices 16 via an input / output port (I / O2) 22.

[0028] The one or more computing devices 16 may include input / output ports 18, 22 (and any additional ports) connected for data communication with one or more processors 20. Note that the one or more processors 20 may be connected for data communication with one or more non-transitory memory devices. An example includes one or more processors 20 and one or more non-transitory memory devices 24. The one or more computing devices 16 may also have additional components, not illustrated, connected for data communication with the one or more processors 20.

[0029] The one or more computing devices 16 can be programmed such that one or more processors 20 perform multiple tasks (e.g., as shown in FIGS. 1 and 2 ) based on instructions stored in one or more non-transitory memory devices 24. The one or more computing devices 16 can be implemented as a desktop computer, a portable computer (e.g., a laptop, a smartphone, a tablet, etc.), etc. The one or more computing devices 16 can function as a controller (either with human intervention or autonomously) to perform neurofeedback training. It should be noted that the one or more computing devices 16 are not limited to only the components described above, and the one or more computing devices may have additional components not illustrated.

[0030] The one or more non-transitory memory devices 24 may be configured to store machine-readable instructions and / or data. The one or more non-transitory memory devices 24 may be embodied, for example, as volatile memory (e.g., RAM), non-volatile memory (e.g., hard disk, flash memory, solid-state drive, etc.), or a combination of both. One or more processors 20 (e.g., one or more processor cores) may be configured within the system to access the one or more non-transitory memory devices 24 and execute the machine-readable instructions.

[0031] By way of example, the one or more non-transitory memory devices 24 may store various machine-readable instructions and data, including an operating system, one or more application programs, other program modules, and program data. The operating system may be any suitable operating system or combination of operating systems, which may vary from manufacturer to manufacturer and system to system. In some examples, the application programs and program modules may implement some or all of the neurofeedback training. For example, the program modules may include a baseline module 26, a score module 28, and a feedback module 30 (although the system 10 may have more program modules than those illustrated). Additionally, the non-transitory memory 24 may store parameters 32 (e.g., data, settings, etc., related to a user and / or a neurofeedback training trial) or other information related to a user and / or a neurofeedback training trial. By way of example, the parameters 32 may include adjustment parameters for a user's score.

[0032] 2, a neurofeedback training trial using system 10 may include a fixation period 44, an induction period 46, and a feedback period 48. The baseline module 26 may be executed during the fixation period 44, the score module 28 may be executed during the induction period 46, and the feedback module 30 may be executed during the feedback period 48. The program modules may also be executed partially or completely during periods different from those just described.

[0033] The fixation period may be a time when the user gazes at a fixation point 42 on the display 14. For example, the fixation point 42 may be a visual image, such as a shape on the monitor (display 14). However, the fixation point 42 does not have to be a visual image. The fixation period may be, for example, 20 seconds or less, 10 seconds or less, or 5 seconds or less. A baseline score may be determined by the baseline module 26 during the fixation period 44 (e.g., based on data recorded by the scalp electrodes 12 during the fixation period and / or based on stored data, the data may be preprocessed). Alternatively, or additionally, the baseline module 26 may adaptively determine a baseline score during at least a portion of the induction period 46. When the user is not actively creating mental images, the baseline module 26 may determine a baseline score based on the user's neural activity. In some cases, the baseline score may be set to a zero value (e.g., by the score module 28), and the score may be adjusted based on the zero value. Note that the fixation period 44 and the induction period 46 do not have to be distinct periods occurring consecutively. Alternatively, the locking period 44 may occur during the induction period 46 .

[0034] The induction period 46 can occur after the fixation period 44 (e.g., 5 seconds or less), although the fixation period 44 may alternatively occur within the induction period 46. During the induction period 46, the user can create (or mentalize) a mental image, and the scalp electrodes 12 can record the user's neural signals while creating / mentalizing the mental image. The mental image may be a mental sensory experience that may resemble the user's experience (such as perceiving an object, event, and / or scene). During a neurofeedback training trial, the mentally perceived object, event, and / or scene does not actually present to the senses. Note that an individual user's mental image need not be the same as another user's mental image. Also, note that if a single user completes multiple neurofeedback training trials, the user's mental image may, but need not, be different during one or more periods of the trial. Note that in most cases, the system 10 does not provide the user with prompts regarding the content of the mental image (or even whether the mental image should be auditory, visual, tactile, etc.). However, in some cases, the system 10 may indicate on the display that the user should start / stop creating a mental image. Note that during the induction phase 47, target features may be calculated. The target features may be in the neural signals from the scalp electrodes 12 and may be used to determine / adjust the score.

[0035] During the induction period 46, the user's performance in constructing the mental imagery can be scored (e.g., by the scoring module 28). As an example, the performance can be scored based on changes in the neural activity recorded by the scalp electrodes 12 (e.g., one or more cortical regions). loose potential), a score relative to the baseline can be determined. looseThe potential is a change in the electrical potential associated with an event in the cortical electrical activity, typically seen in neural signals lasting from a few hundred milliseconds to a few seconds, such as contralateral delayed activity (CDA). However, depending on the cognitive function to be improved, the cortical activity other than CDA may be affected. loose Electrical potentials can also be used, for example, to measure one or more cortical signals in neural activity. loose The potentials may reflect bilateral or unilateral hemispheric activity, or bilateral differences between hemispheres. The score involves comparing neural activity related to cognitive function during an induction period with baseline neural activity. The baseline may be the same cortical or cortical activity as the score. loose Note that it can also be based on potential.

[0036] After the score is calculated (e.g., by the score module 28), feedback is displayed (e.g., visually, audibly, and / or tactilely) via the display 14 (e.g., by the feedback module 30) during the feedback period 48. The feedback can illustrate success with respect to a particular cognitive function. The feedback can be a representation of the score (e.g., a good score may have a positive graphical and / or a positive auditory indication, and a poor score may have a negative graphical and / or a negative auditory indication). For example, the score can be displayed on the display 14 (which may include an indicator of whether the score is good or poor). As one example, the score can be displayed within five seconds after the neural signals are recorded. As another example, the score can be updated at regular intervals (e.g., predefined intervals) during the test to encourage the user to create a better mental image (or improve the mental image). The score may be adjusted during the test so that the user is informed of their progress. If the neurofeedback training includes multiple trials, the feedback period 48 can include the feedback module 30 instructing and / or encouraging the subject to improve their score in the future. The goal of neurofeedback training is to improve the user's cognitive function (which can be improved regardless of whether the user is successful during a particular test).

[0037] IV. Method Another aspect of the present disclosure may include methods 50 and 60 (FIGS. 3 and 4) for providing neurofeedback training based on neural signals related to mental imagery. Methods 50 and 60 may be performed using system 10 shown in FIGS. 1 and 2. Specifically, one or more steps of methods 50 and 60 may be stored in memory 24 and executed by processor 20.

[0038] For simplicity's sake, methods 50 and 60 are shown and described as being performed sequentially. However, it should be understood and appreciated that the present disclosure is not limited by the illustrated order, as some steps may occur in different orders and / or concurrently with other steps shown and described herein. Also, not all of the illustrated aspects are required to implement methods 50 and 60, and methods 50 and 60 are not limited to the illustrated aspects.

[0039] Referring now to FIG. 5, illustrated is a method 50 for performing a single trial of neurofeedback training as described herein. This method 50 can be performed multiple times over a period of time until the neurofeedback training is completed. This period of time may be on the order of minutes, hours, days, weeks, months, or years. The goal of method 50 is to improve certain cognitive functions. Cognitive functions may include, for example, visual attention, working memory (also referred to as visual working memory), concentration, short-term memory, emotion, creativity, etc.

[0040] At 52, neural signals recorded (e.g., by scalp electrodes 12) while the user is creating the mental imagery can be received (e.g., by computing device 16). The neural signals can quantify visual working memory and / or another cognitive function related to the mental imagery. The scalp electrodes can be positioned on the user's scalp and may include active or passive electrodes. The scalp electrodes may be coupled to one or more posterior parietal channels and / or one or more occipital channels (e.g., EEG channels).

[0041] At 54, target features (e.g., features of the neural signals) can be calculated from the neural signals. For example, the target features can be associated with target cognitive functions sought to be improved by neurofeedback training. At 56, a feedback score can be adjusted (e.g., by feedback module 30 of computing device 16) based on the target features.

[0042] The user's performance can be scored (e.g., by the scoring module 28 on the computing device 16 using the adjusted feedback score) based on the neural activity in the neural signals. The score can occur during the induction period or can be based on a baseline score (determined during the fixation period or during the induction period when the user is not creating or attempting to create a mental image). The induction period can follow the fixation period, but the fixation period can occur within the induction period. During the induction period, the user can create (or mentalize) a mental image, and neural signals can be recorded from scalp electrodes. A mental image can be a sensory experience that can resemble the user perceiving an object, event, and / or scene, but occurs when the relevant object, event, or scene is not actually presented to the senses. A mental image can be created / formed by the user without being prompted as to what to imagine. For example, the mental image can be based on a memory specific to the user. The mental image can, but need not, be different for different users and / or for each neurofeedback training trial. For example, one user may form a mental image of an auditory sound (e.g., hearing their mother's voice), while another user may form a visual mental image of a sunny day at the beach. In other words, the particular mental image is not important; the fact that the user is creating a mental image is the subject of neurofeedback. Also, note that an individual user's mental image may change over multiple trials of neurofeedback training. The user is not provided with prompts regarding the content of the mental image, but may be provided with prompts instructing the user to start / stop creating the mental image.

[0043] Feedback may be provided to the user (e.g., via the display 14) to inform the user of their success rate with the mental imagery. The feedback may indicate the user's success in creating the mental imagery and may be associated with an improvement in a particular cognitive function. For example, a score may be presented by the display 14 (which may include an indicator of whether the score is good or bad). The score may be displayed visually, audibly, tactilely, or otherwise. As one example, the score may be displayed after recording neural signals. As another example, the score may be updated at regular intervals (e.g., predefined intervals) during the test to encourage the user to improve their mental imagery during that test. After each neurofeedback training trial, the subject may be instructed to improve their score in the future. The goal of neurofeedback training is to improve the user's cognitive function (which may occur regardless of the success of a single trial).

[0044] Referring now to FIG. 6, illustrated is an exemplary method 60 for providing a score for a single trial of neurofeedback training (such as the trial shown in FIG. 3). It should be understood that different / additional steps may be required to calculate the score. At 62, baseline neural activity may be determined (e.g., by baseline module 26 of computing device 16). The baseline may be determined during a fixation period. The fixation period may be when the user gazes at a point on the display (e.g., fixation point 42 on display 14) (or other type of visual imagery, but not necessarily a visual imagery). The fixation period may be, for example, 20 seconds or less, 10 seconds or less, or 5 seconds or less. A baseline score may be adaptively determined during the fixation period or at least a portion of the induction period. When the user is not actively creating a mental imagery, the baseline score may be based on the user's neural activity. In some cases, the baseline score may be set to a zero value, and the score may be adjusted based on the zero value. Note that the fixation period and the induction period may be different periods occurring consecutively, but need not be different periods occurring consecutively. Alternatively, the locking period may occur during the induction period.

[0045] At 64, neural signals indicative of neural activity can be received (e.g., by I / O 118 of computing device 16). During the induction period, the user can create (or mentalize) a mental image, and scalp electrodes (e.g., scalp electrodes 12) can record the user's neural signals as the user creates / mentalizes the mental image. The neural signals can be preprocessed before further action occurs. The mental image may be a mental sensory experience that may resemble the user's experience of perceiving (an object, event, and / or scene). During a neurofeedback training trial, the mentally perceived object, event, and / or scene does not actually present to the senses. It should be noted that an individual user's mental image need not be the same as another user's mental image. It should also be noted that if a single user completes multiple neurofeedback training trials, the user's mental image may, but need not, differ during one or more periods of the trial.

[0046] At 66, neural activity of the neural signal can be scored (by scoring module 28 of computing device 16) relative to baseline neural activity. Scoring can occur, for example, during an induction period and can include comparing neural activity related to cognitive function during the induction period to baseline neural activity. As an example, a change in one aspect of neural activity (e.g., one or more cortical regions) can be detected. loose Based on the cortical potential, a score can be determined relative to the baseline. loose The potentials are usually contralateral delayed activity (CDA) (however, other cortical potentials may be present depending on the cognitive function being targeted for improvement). loose The electrical potentials associated with an event in the cortical electrical activity, such as the electrical potentials of one or more cortical neurons in neural activity, may be used. loose The potentials can reflect bilateral or unilateral hemispheric activity, or bilateral differences between hemispheres.

[0047] IV. Experiment The following experiment demonstrates neurofeedback training using electroencephalogram (EEG)-based visual imagery, which can be used with the systems and methods described herein. Neurofeedback training can improve one or more core cognitive functions, including higher-order cognitive functions believed to be common to various cognitive abilities. Such core cognitive functions include working memory capacity (specific to attention and memory functions) and neural signatures reflecting working memory capacity, contralateral delayed activity (CDA), slow event-related potential (ERP) components, which are well-established ERP markers found in EEG readings but have not yet been used in real-time neurofeedback training. Furthermore, neurofeedback training can alter the anatomical organization of the cortex connected to the improved cognitive functions.

[0048] procedure: Study participants (n=14), also known as users, were randomly assigned to one of two groups: one group (n=7) was trained with left-hemisphere dominant CDA ('LHG') and the other group (n=7) was trained with right-hemisphere dominant CDA ('RHG') (Figure 5). Note that bilateral dominant CDA ('BHG') was not investigated, but is shown for the purposes of the sample use-case, as shown in Figure 5.

[0049] Each group participated in 100 trials of neurofeedback training (20 trials per day for 5 days). The following example exploits the human ability to learn and accumulate statistical experience about neural activity through these trials and neurofeedback training over several days. Without neurofeedback training, neural activity is typically difficult to recognize. Each day, each participant's task was to achieve high scores on as many trials as possible. Learning (e.g., understanding the state of brain activity) was based on trial and error. At the end of each day, participants were informed of which trials were successful (success was measured as a feedback score of 50 or higher, equivalent to a value exceeding one standard deviation compared to the participant's baseline period). Each participant was asked what image they had in mind for that trial. Participants' task, especially in the final training session, was to find a unique strategy to achieve high scores on as many trials as possible (scores ranged from a minimum of 0 to a maximum of 100).

[0050] As shown in Figure 6, each trial is divided into a fixation phase (lasting 4000–5000 ms to determine the baseline), a go phase (lasting 5000 ms during EEG recording), a stop phase (lasting 2500 ms during preprocessing), and a feedback phase (lasting 3000 ms during trial scoring). During the fixation phase, participants are asked to fixate their eyes on a fixation point at the center of a circle. During the go phase, participants are asked to close their eyes and form a mental image (or "mentalize") of anything they want until the stop phase, during which they are free to open their eyes and stop mentalizing. To minimize any bias related to mental imagery, participants are only informed that the target neural activity is thought to be related to visual attention. During the go phase, high-quality EEG data are collected from 32 active electrodes (Brain Products, actiCAP, BrainAmp Standard amplifier) ​​covering each participant's entire scalp. The CDA component of the EEG data is calculated in real time as participants concentrate on creating a mental image. Next, the CDA components are quantified and a score (0 to 100) is visualized on the screen during the feedback phase.

[0051] EEG procedure Figure 7 illustrates the post-study analysis workflow. EEG signals were continuously monitored using a BrainAmp Standard amplifier with 32-channel actiCAP electrodes from Brain Products GmbH, and extracted to a PC in real time (500 Hz) during each trial using Brain Products GmbH's remote data access (RDA) TCP / IP protocol. For each trial, single-trial ERPs (event-related potentials) relative to the onset of the "Go" array were calculated from the posterior parietal and paraoccipital channels (i.e., P5 / 6, P7 / 8, PO3 / 4, PO7 / 8, and O1 / 2). At the signal offset, the raw EEG data were low-pass filtered at 30 Hz using an inverse fast Fourier transform filter (no high-pass filter). The raw EEG data were then re-referenced to the mastoid and normalized to the baseline period (the baseline period was 5000 ms before the onset of the "Go" signal). Any channel with excessive amplitude change (>100 μV / s) within a single trial was excluded. Next, the average ERP for each hemisphere was obtained (one average ERP for the left hemisphere channel and another average ERP for the right hemisphere). During the baseline period (baseline period = -500 to 0 ms relative to the onset of the go signal), the absolute amplitude of the resulting average ERP was converted to a Z-score by normalizing the absolute amplitude with the average activity of all corresponding channels. For each hemisphere, the Z-transformed amplitude from the go phase was averaged across the entire electrode array (go phase = 0 to 5000 ms after presentation onset). Then, for each hemisphere, the averaged Z-transformed amplitude was averaged across all corresponding channels. The difference in Z-scores between the two hemispheres was calculated, and the Z-scores were converted to percentiles using a normal cumulative distribution function. If the Z-score of the target hemisphere was larger (more negative) than that of the other hemisphere, a larger circle was presented to the participant. If the score of the target hemisphere is smaller (more positive) than that of the other hemisphere, a smaller circle is presented to the participant. The diameter of the circle ranges from 1.6° to 20° of visual angle.The circle size and score visualization are adjusted to clearly know when participants have a higher score, to encourage trials that produce larger CDA and discourage trials that produce equal or smaller CDA amplitudes on both sides.

[0052] result Figure 8 shows EEG responses during the neurofeedback test. The grand average difference ERP (Figure 9) demonstrates that each group successfully generated their CDA in a consistent manner as expected. The left hemisphere group ('LHG') successfully generated a leftward CDA from approximately 3 to 400 ms. The induced CDA improved over the training session (Figure 10). These results demonstrate that CDA neurofeedback was successful at the group level.

[0053] We assessed individual users' attention and working memory performance before and after CDA neurofeedback training. After five days of intensive training, participants, regardless of group assignment (Figure 11, left), significantly improved their ability to focus (attentional efficiency). Most importantly, the method reliably improved working memory performance with a high effect size (Cohen's standard deviation, 0.94; Figure 4, right), a finding not previously possible. Furthermore, Figure 12 shows that increases in working memory performance correlated with the degree of left-sided CDA (left), while behavioral changes were not related to the degree of right-sided CDA (right).

[0054] From the above description, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications are within the skill of those skilled in the art and are intended to be covered by the appended claims.

Claims

1. 1. A system configured to engage a subject in a neurofeedback training trial, comprising: a memory for storing instructions; a processor, The processor accesses the memory and executes the instructions, receiving neural signals, including slow cortical potentials, from a plurality of scalp electrodes positioned on the subject's scalp, the neural signals quantifying the subject's visual working memory related to the subject's creation of mental images from memory; determining a baseline based on the subject's visual working memory related neural activity during a fixation period, and then comparing the neural activity during an induction period in the neural signal to the baseline, thereby determining a score for the subject's performance relative to the baseline based on the slow cortical potentials indicative of changes in the neural activity; and configuring the subject to provide feedback based on the score to inform the subject of a success rate related to the visual working memory; wherein the cortical slow potentials reflect contralateral slow activity, bilateral or unilateral hemispheric activity, or bilateral differences between hemispheres; the mental image is created by the subject based on a memory specific to the subject without prompting the subject as to what to imagine; After said test, attention and / or visual working memory function of said subject is improved.

2. 10. The system of claim 1, further comprising the plurality of scalp electrodes configured to be positioned at predetermined locations on the subject's scalp to record the neural signals.

3. The system of claim 2 , wherein the plurality of scalp electrodes includes active and / or passive electrodes.

4. 3. The system of claim 2, wherein each of the scalp electrodes is associated with a channel, the channel being at least one of a posterior parietal channel and an occipital channel.

Images