JP4655821B2 - Stimulus display device for brain function measurement - Google Patents

Description

  The present invention relates to a device that supports measurement of human brain function, and more particularly to a stimulus presentation device and method used when stimulating a subject and measuring brain function based on the reaction.

  In recent years, techniques for measuring human brain functions in a non-invasive manner have been developed, and the mechanism of the brain has been elucidated. For example, optical brain functional imaging using functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy measures changes in local blood volume and blood oxygenation status associated with brain activity. This is a typical brain function measurement technology that visualizes spatial information of brain function. Since these techniques cannot measure the absolute value of brain activity, the subject's state is changed from a certain state to another state, and the brain activity is evaluated by using the relative change in blood volume as an indicator. Therefore, in order to measure the target brain function, it is necessary to control the state of the subject so as to extract only changes associated with the brain function. Therefore, in order to control the state of the subject, a method of giving some kind of stimulus or task to the subject is generally employed. For example, the activity of the visual cortex can be measured by having the subject gaze at the display, and alternately repeating the period for presenting the fixed viewpoint and the period for presenting the visual stimulus in which the lattice pattern switches at a high cycle. Alternatively, when the subject in a resting state is allowed to perform finger movement for a certain period, the activity of the corresponding motor area can be measured. In both cases, a measurement signal in one period is used as a comparison target (baseline), and a change associated with a certain stimulus or task is measured as brain activity. In general, measurement data includes device noise and systemic physiological changes (changes in heart rate and blood pressure) in addition to brain activity signals, so each stimulus is repeatedly applied about 5 to 10 times. In general, only changes derived from brain activity are detected.

  In order to detect brain activity signals from measurement data, it is necessary to present stimuli that can be described quantitatively at precisely controlled timings. Therefore, a personal computer (PC) is usually used for a series of stimulus presentation processes. Use. Moreover, since the timing of stimulus presentation must be recorded in the brain function measuring device for analysis, a function for outputting an external signal (serial command or analog signal) is required. The PC is also useful in the function of outputting an accurate external signal at an accurate timing.

  Stimulus patterns used in brain function measurement are determined from many parameters such as types and combinations of stimuli, presentation order, and presentation time, so the experimenter creates his own program in an arbitrary programming language and creates the target brain Functional measurement has been realized. As a product of stimulus presentation software, “Presentation (Neurobehavioral Systems, USA) (Non-Patent Document 1)” is already on the market. In addition, research institutes such as universities are also promoting the presentation of stimulus presentation programs (“Psychophysics toolbox (Non-patent Document 2),“ cogent (Non-patent Document 3) ”) However, both methods are configured so that the experimenter performs programming, which is designed to create a pattern of stimulus presentation as freely as possible, assuming that the researcher is the main user. Because it is.

  As an effective stimulus presentation method, the method of randomizing the order of the stimulus and the presentation time so that the subject cannot predict the type and timing of the next stimulus has been widely used in the past brain function measurement. A published patent information (Patent Document 1) also discloses a stimulus presentation device characterized by randomizing the order of stimulation presented by a PC and the presentation time.

  Further, a method has been devised in which biological signals such as brain function measurement signals are analyzed and the timing of stimulus presentation is determined based on the fluctuation component (Patent Document 2). Similarly, a method has been devised for determining the timing of stimulus presentation based on a noise component (body motion noise) associated with body movement determined from an infant brain function measurement signal (Patent Document 3). These are thought to be effective in reducing the effects of biological fluctuations and body movement noise and measuring brain activity efficiently.

  On the other hand, Patent Literature 4 invents a training support device that adjusts the continuation of training and the difficulty level of a training task based on the training result of a subject. In the present invention, for the purpose of optimization of training, the next task content is determined using the response of the subject and the brain activity signal as an index.

http://nbs.neuro-bs.com/nbs_online/presentation

http://psychtoolbox.org/ http://www.vislab.ucl.ac.uk/CogentGraphics/index.html Maki, A et al., (1995) “Spatial and temporal analysis of human motor activity using noninvasive NIR topography” Medical Physics 22, 1997-2005. JP 2003-159253 A JP 2004-141285 A JP 2004-261265 A JP 2004-294593 A

  In order to measure brain function with high accuracy, several methods for presenting stimuli as described above have been proposed, but the effect is still not sufficient. One reason is that the optimal stimulus type and presentation time cannot be set for each subject even though the subject's difficulty level and the speed of acclimatization to the stimulus vary from subject to subject. By randomizing the stimulus presentation pattern, it is possible to prevent the subject from being predicted or accustomed to the stimulus to some extent, but the stimulus presentation pattern is not optimized for each subject. Many studies have examined appropriate stimulation and presentation timing through preliminary experiments, but these are presentation stimulation patterns that are determined according to the average of multiple subjects. A suitable fine setting is not possible. After measurement, it is common practice to evaluate the quality of the stimulus by analyzing the behavioral response (response time and correct answer rate) to each subject's stimulus (task). However, variations in measurement data due to the difference cannot be corrected.

  Also, the pattern of brain activity signals varies from subject to subject, and the time required for the signal to stabilize as a baseline after the activity (relaxation time) varies from person to person. Since the interval between stimuli (stimulus-stimulus interval) must be set to be longer than this relaxation time, it is longer than the stimulus-stimulus interval based on the average relaxation time or the relaxation time of all subjects. A set stimulus-stimulus interval has been commonly used. However, from the viewpoint of measurement time, it is desirable to reduce the burden on the subject by setting a stimulus-stimulus interval as short as possible. Even if the stimulus presentation method considering the pattern of biological fluctuation is used, the relationship between spontaneous biological fluctuation and brain activity to the presented stimulus has not been elucidated, so the effect is limited to reducing the influence of biological fluctuation Has been.

  As described above, conventionally, since the stimulus pattern to be presented is uniformly determined regardless of the characteristics of the subject and the state at the time of measurement, the optimum stimulus type and presentation time have not been set for each subject. The training support device of Patent Document 4 has a function of evaluating the training effect with a behavior index or a brain activity signal and reflecting it in the next training task. However, the adjustment of the training task is only for the purpose of improving the training effect, and is not intended to improve the accuracy of the brain function measurement and the efficiency of the measurement.

In general, stimulation presentation for brain function measurement is controlled by a PC, and an appropriate computer program is required to execute the intended stimulation presentation pattern. Therefore, the measurer had to create a new program or modify an existing program according to the measurement purpose. However, when creating a stimulation pattern by operating the program itself, there were the following problems.
・ Working time varies depending on the proficiency level of programming skills. ・ It is difficult to modify the program except for the program creator. In particular, the type of stimulation and the presentation time are randomized, and stimulation is performed according to the subject's behavioral response and brain activity signal. When changing the type and presentation time, or making complicated settings, advanced programming techniques are required, so it is difficult for non-specialists to create programs. Furthermore, the stimulus presentation device and the brain function measurement device are independent devices, and appropriate parameters must be set for the brain function measurement device according to the stimulus to be presented. However, since the two devices are set independently, the operation is complicated and the possibility of human error is high.

  Opportunities for measuring brain function are also increasing in the medical field, and it is becoming increasingly necessary for people other than researchers familiar with brain function measurement to easily measure brain function. If a specific stimulus presentation pattern and measurement method according to the measurement purpose have been established, simple and automated measurement is possible, but at present, the method is perfectly optimized for any measurement purpose. Does not exist. Therefore, it is necessary to measure brain function effectively by executing an appropriate stimulus presentation pattern according to the measurement environment and the condition of the subject as easily as possible.

  In order to provide a stimulus presentation pattern suitable for each subject, a stimulus presentation device that can set the presentation stimulus and its presentation time and timing using behavioral responses from the subject, brain activity signals, or other physiological change indicators, etc. provide. For example, when the stimulus presentation time and the difficulty level of the task are adjusted according to the behavioral response of the subject, it is possible to present a stimulus having the same level of difficulty for each subject. In addition, in order to shorten the measurement time, it has the function to present the next stimulus based on the time when the brain activity signal generated by the stimulus presentation returns to the level before the stimulus presentation again, and the stimulus as short as possible- Set the stimulation interval.

  In addition, in order to make it possible to easily measure brain function even if it is not an expert, a stimulus presentation device is provided that can set and execute presentation stimuli and their presentation order and presentation time by a table or list. Furthermore, it has a function of displaying appropriate parameters of the brain function measuring device according to the set stimulus presentation pattern. This function not only displays the appropriate parameters of the brain function measuring device, but can also automatically set the brain function measuring device by sending digital and analog signals.

  According to the present invention, it is possible to adjust the intensity of stimulation and the difficulty level of a task according to the subject or the state of the subject, and the brain function can be accurately measured.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an embodiment of brain function measurement using the stimulus presentation device of the present invention. The stimulus presentation device 102 includes a user interface unit 101 that performs display to the measurer and inputs from the measurer, and a stimulus presenter that performs presentation to the subject. The stimulus presentation unit includes a display 103 that presents visual stimuli to the subject, a speaker 104 that presents auditory stimuli, and a vibration box 105 that presents tactile stimuli. The stimulus presenting unit is not particularly limited as long as it stimulates five human senses. In parallel with the brain function measurement by the brain function measuring device 106, the subject receives a stimulus from the stimulus presenting unit and transmits a behavioral response to the response processing device 108. The response processing device 108 is, for example, manually pressed buttons, a camera that measures eye movement, a microphone that senses voice, or the like. It is also possible to install a button on the vibration box 105 and also use it as a stimulus presentation unit. The stimulus presentation device 102 outputs a marker signal related to the type and timing of the stimulus to the brain function measuring device 106 and records it in the brain function measuring device. The brain activity signal and the marker signal measured by the brain function measuring device 106 are analyzed by the signal processing device 107, and the reference signal 1 is output to the stimulus presenting device 102. The reference signal 1 is, for example, the magnitude of the brain activity signal, the magnitude and frequency of biological fluctuations included in the brain activity signal, the magnitude and frequency of artifacts accompanying body movement, and determines the type and timing of the stimulus to be presented It can be used as a parameter. Similarly, the reference signal 2 is output from the response processing device 108 to the stimulus presentation device 102. The reference signal 2 is, for example, the response time of the subject and the type of button, and the stimulus presentation device 102 calculates the response time from the start of stimulation, the correct answer rate, and the like. Information on these subject responses can also be used as parameters for determining the type and timing of the stimulus to be presented.

  Examples of the brain function measurement apparatus used in the present invention include functional magnetic resonance imaging (fMRI) and biological light measurement apparatus. Here, the biological light measurement device will be briefly described with reference to FIG.

  Irradiate light from the head of the subject (human) with a light intensity peak wavelength in the visible to near-infrared region, which is highly permeable to the living body. It is possible to noninvasively measure information on changes in hemoglobin concentration in the cerebral cortex (measurement site) between positions (Non-Patent Document 4). In particular, the change can be measured as an image by arranging a plurality of measurement points in a grid pattern. With the activation of human perceptual function and motor function, the blood volume in the cortical cortex that controls the function increases locally, and the concentration of oxygenated hemoglobin and deoxygenated hemoglobin in the corresponding region changes. ， Evaluate the activity status of the brain. In addition, this technique has a feature that it is possible to easily measure brain function without invasion and low restraint on a subject.

  FIG. 2 shows an embodiment similar to that of FIG. 1 except that the marker signal output from the stimulus presentation device 102 is directly input to the signal processing device 107 and analyzed. Since the marker signal is necessary for the analysis of the measurement signal, it may be input to either the brain function measurement device or the signal processing device.

  FIG. 3 also shows an embodiment similar to FIGS. 1 and 2, but shows a case without a signal processing device. For example, when functional magnetic resonance imaging (fMRI) is used in a brain function measuring apparatus, a case where a pulse from fMRI is directly used as the reference signal 1 is applicable.

  FIG. 4 shows a configuration example of the user interface unit 101 designed to display information on the stimulus presentation pattern and be operated by the measurer. The present invention mainly relates to the user interface unit. There are six basic screens. From the main screen 401 that selects and executes stimulus presentation patterns, a file that edits the “stimulus list” file that lists the stimulus names to be used and the “presentation table” file that controls the presentation patterns. A transition is made to an edit screen 402 and an input / output setting screen 403 for setting external input / output. In this embodiment, a series of stimulus presentations defined by the “stimulus list” and “presentation table” is defined as individual “presentation patterns”. From the file editing screen 402, the screen further transits to a random stimulus setting screen 404, a response dependent stimulus setting screen 405, and a brain activity signal dependent stimulus setting screen 406.

  An example of the main screen 401 is shown in FIG. In 501 part, the start method of stimulus presentation is set. Here, one of four types, “MRI pulse”, “RS232C signal”, “subject button”, and “single” is selected by radio button. When any of “MRI pulse”, “RS232C”, or “subject button” is selected, the set presentation pattern is started when the input of the selected signal reaches the number in the right text box. When “single” is selected, it means a software single operation of the present stimulus presentation device, and when the measurer presses the start button 516, the presentation pattern is started. In 502, the type of stimulus to be presented is selected. Here, three types of “visual stimulation”, “auditory stimulation”, and “visual + auditory stimulation” are shown, but “tactile stimulation”, “olfactory stimulation”, and the like can be added here. Since the setting of 502 is a visual stimulus alone and it is not necessary to determine the main presentation as a specific sensory modality, the radio button for the main presentation cannot be set. Select the stimulus presentation pattern to be used from the pull-down menu of 506. The pull-down menu displays an existing stimulus presentation pattern in the category of the stimulus type set in 502. Further, the output data file in which the presentation contents and the input / output signals are recorded is selected by selecting a storage location with the reference button 509 and the file name is entered in 508 to set the storage status. After selecting the stimulus presentation pattern and determining the output data file, the check start button 507 is used to check all the setting files for errors. If there is no error, the stimulus presentation contents display section (511) displays the visual list file name (512), the auditory list file name (513), the presentation table file name (514), and the presentation table contents (518). Is displayed, and if there is an error, the error is displayed. The start and stop of the stimulus presentation pattern is controlled by the start button 516 and the stop button 517, but in FIG. 5, since the presentation pattern file is not selected, it cannot be pressed. In addition, in the check box (503) on the main screen, it is determined whether or not to output a voice based on whether or not the subject's response is correct. If checked, a voice message is output to indicate correctness / incorrectness according to the subject's response. In addition, the main screen is ended by an end button (504).

  FIG. 6 shows a screen in which the stimulus presentation pattern is selected and the file is checked. The stimulus type was “visual + auditory” and the main presentation was auditory (601). This is a screen after selecting the presentation pattern “stroop01” (602) and the output data file “050606ss” (603), and the stimulus start button (608) can be pressed. When multiple sensory stimuli such as “visual + auditory stimuli” are given, set which of the sensory stimuli has priority in the setting file with the radio button at the location marked “main presentation”. This is because, in the presentation table 611, when the time for presenting one stimulus is different between visual and auditory sense, the location (row) of the stimulus is shifted. This is information for determining whether to execute output signal or response recording.

  Details of the presentation table are displayed in the table (611) below, along with the file names of the set visual list (604), auditory list (605), presentation table (606), and output file (607). “Number” in the first column indicates a row number, and “Image number” and “Voice number” in the second column and third column indicate an image stimulus number in the visual list and an audio stimulus number in the auditory list, respectively. In the fourth column, “Unit”, the presentation time of each stimulus is set in time (milliseconds), set by the number of input MRI pulse sounds, set by the behavioral response from the subject, or brain function Determine the unit for setting the stimulus presentation time, such as whether to set by RS232C command based on the signal. Here, 0 is set as the time (milliseconds). In the case of brain function measurement by MRI, it is possible to measure a functional image at a target timing by controlling the stimulus presentation timing by the number of MRI pulses. In addition, if the stimulus presentation timing is controlled by the subject's behavioral response, the stimulus can be presented at an appropriate pace in accordance with the behavioral response time that differs for each subject. Furthermore, if control is performed according to the RS232C command based on the brain function signal, it becomes possible to present the next stimulus after the signal has settled to the original level again after the activity has occurred.

  In accordance with the unit set in the fourth column “unit”, the image presentation time (fifth column) and the voice presentation time (seventh column) are set. This presentation time may be set to the type of button signal in the case of the subject's behavior response, or to the type of command in the case of the RS232C command based on brain function signals. Moreover, after actually presenting those stimuli, the accuracy of the presentation time can be confirmed by displaying the respective execution times in the sixth and eighth columns. In the ninth column, the RS232C command to be output to the brain function measuring device is set. For example, if you send an “ST” command at the beginning of the presentation pattern and the brain function measurement device receives the “ST” command, you can set the measurement to start. Measurement can be started. In the 10th column, a signal that is correct as a response from the subject is set. The actual response is recorded in the 11th column, and the correctness / incorrectness of the response (12th column) is determined by seeing the coincidence of the 10th and 11th columns. In addition, the response time (13th column) is measured by measuring how many milliseconds after the stimulus is presented in the row. Whether or not the button function itself is effective is displayed in the 14th column so that the correctness / incorrectness determination is not mistaken due to the failure of the button or the like. During execution of the presentation pattern, the row being presented is shown as the selected row in Table 611, and the row number is displayed on 609 (visual stimulus) and 610 (auditory stimulus), allowing the measurer to check the presentation status in real time. To help. In FIG. 6, since the state is waiting for the start button to be pressed, the first line is selected, and “1 (line)” is displayed in 609 and 610, respectively.

  It is also possible to change the starting line by changing the selected line in table 611 before starting. For example, FIG. 7 is obtained by changing only the selected row from the setting of FIG. Since the fourth row is selected (703), “4 (row)” is displayed in 701 and 702, and the presentation starts from the stimulus in the fourth row by the start of the presentation pattern. After completion of the presentation pattern, the average correct answer rate (519) and the average response time (521) are displayed from the correctness / incorrectness determination.

  A main screen configuration as shown in FIG. 8 is also possible. Here, a screen after setting the presentation pattern (801) and the output data file (803) and then pressing the check start button (802) is shown. A measurement site suitable for the selected presentation pattern is shown in 804, and an output signal to the brain function measuring device is shown in 806 as the contents of the presentation pattern. In addition to the measurement site, it is possible to display information so that the parameters of the brain function measuring device can be appropriately set according to the presentation pattern. The information to be displayed includes the location and size of the appropriate measurement site, the sampling period of measurement, the wavelength of the light to be measured, etc. In addition to displaying on the screen, the relevant parameters of the brain function measurement device are set directly It is also possible to configure as described above. These measurement parameters can be set in two ways: when set by the stimulus creator and when set automatically from the presented stimulus. In the latter case, for example, when a visual stimulus is included in the presented stimulus, the visual area of the occipital region is set to be included in the measurement site, or an appropriate measurement site is illustrated, and the light wavelength and irradiation-detection suitable for the measurement site The distance can be set in the brain function measuring device. An appropriate sampling period can also be set according to the presentation time of the main stimulus. This function makes it easy for beginners to obtain high-quality measurement data. Also, by showing (806) the presentation pattern, it becomes easier to grasp the entire picture of the presentation pattern, and it becomes easier to find errors. In Table 703 in FIG. 7, the fourth line is selected and the start point is changed, but in 806 in FIG. 8, the start point can be changed by moving the arrow (808) indicating the progress of the presentation pattern as a time series. It is.

  When the external input / output setup button (505) on the main screen is pressed, the screen shifts to a screen shown in FIG. 9 for setting the details of the external input / output. Here, parameters related to the subject's response input by the game pad, the marker signal (RS232C) output to the brain function measuring device, and the screen presented to the subject are set. There are four types of responses of the test subjects (responses 1 to 4), and corresponding buttons are set according to the game pad in FIG. 906 (905). For example, response 1 can be set with a pull-down menu such as button A (901), response 2 with button D (902), response 3 with button E (903), and response 4 with button F (904). In addition, RS232C is set according to 912. The RS232C input command used to start the presentation pattern or as an index of the stimulus presentation time is set at 911. For RS232C output commands, set the output command in the table or figure on the main screen (Figs. 6-8). Detailed parameters for RS232C input / output are set in FIG. 10 displayed by the setup button (909, 910). Detailed parameters are common to input and output, such as transfer rate (1001), data length (1002), stop bit (1003), parity (1004), port (1005), flow control (1006), etc. After setting these with the radio button or pull-down menu, save them with the OK button (1007) or cancel them with the cancel button (1008). In addition, when using the interface screen to the measurer and the display screen to the subject independently, the two screens (multi-monitor) are set at 915. Here, a pull-down menu (913, 914) for setting the resolution of each screen is shown. Similarly, it is possible to make settings for voice stimulation and tactile stimulation.

  Returning to the main screen (FIGS. 6 to 8) again, new creation and editing of a presentation pattern file starting from the pressing of the file editing button (510) will be described. When the file edit button (510) is pressed, the screen shown in FIG. 11 is first displayed. Whether to create a new presentation pattern file, create a new file based on an existing file, or edit an existing file, a radio button Select with, and press the OK button (1101). To cancel, press the cancel button (1102). When a new presentation pattern is created, a screen as shown in FIG. 12 is displayed, a presentation pattern name is input in 1201, and an OK button (1202) is pressed. To cancel, return by pressing the cancel button (1203). When creating a new presentation pattern from an existing pattern, a screen as shown in FIG. 13 is displayed. An existing pattern to be used as a base is selected from the pull-down menu 1301, and a presentation pattern name to be newly created and saved is input to 1302. The process proceeds to the next by pressing the OK button (1303), and returns by pressing the cancel button (1304). When editing an existing presentation pattern, an existing pattern to be edited is selected from a pull-down menu 1401 on a screen as shown in FIG. Similarly, the process proceeds to the next by pressing the OK button (1303), and returns by pressing the cancel button (1304).

  When creating / editing a presentation pattern file, settings are made on a screen as shown in FIG. When the stimulus type set on the main screen (FIGS. 5 to 8) is displayed on 1501, and the stimulus type is composed of a plurality of sensory stimuli such as “visual + auditory”, the set main presentation stimulus is also displayed on 1503. The presentation pattern name to be created / edited is displayed in 1502, the presentation table name is displayed in 1507, and the stimulus list name is displayed in 1508. The contents of the presentation table are displayed at 1509 and the contents of the stimulus list are displayed at 1510, respectively. When editing the contents of the presentation table and the stimulus list, when the line to be edited is selected in each table, the contents of the line are displayed in the editing portion 1511 and can be edited. The contents are edited in the editing portion 1511, and the contents are updated by pressing the update button 1512, and saved in the file by the save button. When a new line is added, a value is entered in the editing portion 1511, and then a line is added by pressing a registration button. If you want to delete an existing line, select that line and press the delete button. If a different presentation table file or stimulus list file is to be used, the file can be loaded by a read button and saved as a presentation table or stimulus list of this presentation pattern. Further, when a long presentation pattern is created by repeatedly using an existing presentation pattern, the “Create from detailed pattern” menu 1506 is effective. Here, the existing presentation table file is read using the reference button, the number of times the presentation table is repeated is set, and then the creation button is pressed. Then, the newly created content is displayed in the presentation table 1509 and is set as a presentation table used in this presentation pattern by pressing the save button 1512. After setting, pressing the end button 1504 returns to the main screen.

The above method is effective for simple presentation patterns that present stimuli specified according to the presentation table in the specified time series, but in actual measurement, the stimuli are in random (random) order. It is also necessary to present different stimuli depending on the subject's response. A stimulus that changes depending on the situation that cannot be set only by the presentation table is defined as “variable stimulus”, and the information is displayed in 1505. Here, three types of variable stimulus are set, and setting information regarding the variable stimulus selected with the radio button is displayed in the right text box. In addition, each setting screen is transitioned to by pressing a setting screen button. (1) Stimulus to present and random stimulus to randomize the presentation time (FIG. 16), (2) Response dependent stimulus to change the presentation stimulus and the presentation time according to the response (input signal) of the subject (FIG. 17), (3) Each setting method of the brain activity-dependent stimulus (FIG. 18) for changing the presentation stimulus and the presentation time according to the measured brain activity of the subject will be described below.
(1) Random stimulus setting When using random stimuli, symbols such as R1 to R3 are set in the stimulus number (image number or voice number) in the presentation table, and the stimulus presented by each symbol is displayed on the screen of FIG. Set with. When R1 is selected in the random stimulus selection menu 1602 of FIG. 16, R1 is displayed in 1606, and a plurality of candidate stimuli are displayed in a text box 1608 below the R1. Candidate stimuli can be selected from the content (1605) of the stimulus list (1604) displayed on the left and added by pressing the arrow button (1607). The added stimulus can be deleted with the delete button 1609 and saved with the save button. After saving, in the row where R1 is marked in the presentation table, one stimulus is selected at random (with the same probability) from the stimuli saved in 1608 and presented. By randomly selecting stimuli, presentation patterns with different presentation orders can be used at all times, and the effect of preventing the familiarity of subjects participating in repeated measurements can be expected. Further, when the measurer creates a plurality of stimulus presentation patterns, labor according to the number of stimulus patterns is required, which is also effective in reducing the work of the measurer.

  The next presented stimulus (post-random stimulus) must be changed according to the stimulus presented in R1, such as not presenting the same stimulus continuously or always presenting this stimulus after a certain stimulus. There is also a measurement paradigm. In that case, a symbol such as R is set for the stimulus number in the presentation table, and R1R is set as (1602 to 1604). When the first candidate stimulus of R1 displayed in 1608 is selected, the stimulus R1R (1611) to be presented after the presentation of the stimulus can be set in the text box (1612). When a stimulus to be presented is selected from the list content 1605 on the left and the arrow button 1610 is pressed in the same manner as R1, it is added to the text box 1612. The stimuli can be deleted with the delete button 1613, and the list 1612 can be saved with the save button. Other R1 candidate stimuli can be similarly set to post-random stimuli to be presented next. Like R1, one stimulus is presented randomly by selecting multiple stimuli. If you want to change the selection probability according to the stimulus, you can change the probability by putting several identical stimuli in the text boxes 1608 and 1612.

When it is desired to set the presentation time at random, symbols such as R1T to R3T are set for the image presentation time or the voice presentation time in the presentation table, and the presentation time for each symbol is set on the screen of FIG. For example, by selecting R1T in the random presentation time setting menu 1603 in FIG. 16 and setting the lower and upper limits of the presentation time in the right text box (eg 10 to 20 seconds), the presentation time of the stimulus set as R1T Is randomly determined between 10 and 20 seconds. R2T and R3T can be set similarly. After setting, pressing the end button 1601 returns to the file editing screen. Randomizing the presentation time makes it difficult for the subject to predict when the next stimulus (task) will be presented and avoids predictive behavioral responses. Also, since the fluctuation cycle of the spontaneously generated signal is almost constant, by randomizing the stimulus presentation timing, spontaneous fluctuations are added and averaged by chance at the same timing, and the brain activity signal accompanying the stimulus presentation It also has the effect of preventing overlapping.
(2) Setting of response-dependent stimulus When changing the presentation stimulus and the presentation time according to the response (input signal) of the subject, it is set as a response-dependent stimulus in FIG. When the response of the subject is 3 types (S1 to S3) of the reference stimulus 2 (FIGS. 1 to 3), the subject response is selected with the radio button 1701, and the next stimulus presentation time when the corresponding subject response is obtained is presented. In the setting menu 1705, the next stimulus to be presented is set in the presentation stimulus setting menu 1707, respectively. The presented stimulus can be selected from the content 1704 of the stimulus list 1703 displayed on the left, and can be selected and saved by pressing the arrow button 1706. By selecting a plurality of stimuli, it can be used as a random stimulus by the method described in FIG. With this function, the next stimulus can be changed according to the response of the subject, so a flexible presentation pattern is possible. For example, when measuring the pleasure / discomfort of a visual stimulus presented on the screen and measuring the brain activity associated with emotion, the presentation method of selecting the next stimulus after evaluating it as a pleasant one from the discomfort group is always used. Is possible. In the case of a stimulation paradigm where the correctness / incorrectness of such issues cannot be determined uniformly, this is useful for counter balancing between stimuli.

Moreover, it is also possible to use S1-3 as correct / incorrect behavioral responses determined from the reference stimulus without assigning S1 to 3 as the reference stimulus classification. In this case, it is possible to present a stimulus according to the condition of the subject, such that when the answer is correct, the problem is more difficult, and when the answer is incorrect, the problem is the same level. On the 1702 feedback control setting screen, the presence or absence of the feedback control function can be selected. The feedback control function is a function that selects the next stimulus so that the correct answer rate (%) and reaction time (ms) are close to each other when the feedback control based on the correct answer rate and the reaction time of the subject is “Yes”. It is. In other words, when the correct answer rate is lower than the set rate, the task is selected as simple as possible, and when it is higher than the set rate, the difficult task is selected. Similarly, it is a function that selects a task to be presented next from a task group at an appropriate level so that the average reaction time approaches the set reaction time. With this function, subjects with different abilities to tasks can be given a load with an approximate value by controlling the presentation stimulus (task). In other words, individual differences that are always a problem in brain function measurement can be optimized from the viewpoint of stimulation (task) for each individual, so that the brain activity between subjects can be compared accurately. This is an effective function.
(3) Setting of brain activity dependent stimulus When changing the presentation stimulus and the presentation time according to the brain activity of the subject, it is set as the brain activity dependent stimulus in FIG. Brain activity signals measured by the brain function measuring device 106 (Figs. 1 to 3) are analyzed by the signal processing device 107 (Figs. 1 and 2). When a positive brain activity signal is generated and then it returns to the signal strength (baseline) in the resting state before stimulation (increased (+ 2SD⇒baseline)) "or" double SD of unstimulated SD If a negative brain activity signal with an amplitude greater than that occurs and then returns to the baseline (decrease (+ 2SD⇒baseline)), etc., and sends it to the stimulus presentation device as reference signal 1 (Figs. 1 and 2) . In the brain activity signal selection menu of 1801, after selecting a brain activity signal to be used for selecting a brain activity dependent stimulus (in this embodiment, selected from oxy-Hb, deoxy-Hb, and total-Hb), the reference signal 1 (In this example, select from “A: increase (+ 2SD) → baseline” and “B: decrease (−2SD) → baseline”). The next stimulus presentation time when the reference signal indicating the corresponding brain activity signal is obtained is set by the presentation time setting menu 1804, and the stimulus to be presented next is set by the presentation stimulus setting menu 1806. Presented stimuli can be selected from the content 1803 of the stimulus list 1802 displayed on the left, and can be selected and saved by pressing an arrow button 1805. By selecting a plurality of stimuli, it can be used as a random stimulus by the method described in FIG. This function makes it possible to present the next stimulus based on the time when the brain activity signal generated by the stimulus presentation returns to the level before the stimulus presentation again, thus realizing the shortest stimulus-stimulus interval. it can. In other words, since the interval between stimuli can be adjusted in consideration of the relaxation time that varies depending on the subject, the measurement time can be shortened by always setting a stimulus-stimulus interval that is shorter than before, thereby reducing the burden on the subject. it can.

  In addition, instead of the response (2) and the brain activity (3), the measurer may observe the actual state of the subject and determine the stimulus presentation. In this case, for example, the measurer can present the stimuli 1 to 4 by pressing the stimulus presentation buttons 2002 to 2005 while viewing the measurement scenery 2001 displayed by the interface as shown in FIG. An end button 2006 returns to the original screen.

  As described above, by using the stimulus presentation device for brain function measurement according to the present invention, it is possible to execute stimulus presentation optimized for each subject, and to perform brain function measurement with higher accuracy and efficiency. Become. It also has a function to support appropriate measurement parameter setting for the brain function measuring device, and even a beginner measurer can obtain high-quality measurement data. In addition, since the interval between stimuli can be adjusted in consideration of the relaxation time that varies depending on the subject, it is possible to set a shorter stimulus-stimulus interval than before, reducing the measurement time and reducing the burden on the subject. Can do. Furthermore, it is possible to create and edit stimulus presentation patterns without requiring special programming skills, and it will be a useful support tool for a wide range of brain function measurement applications. The created stimulus presentation patterns can be managed by stimulus files (image files and audio files) and table files, so they can be easily distributed, edited, and used.

The block diagram which shows one Embodiment of the brain function measurement using the stimulus presentation apparatus of this invention. The block diagram which shows one Embodiment of the brain function measurement using the stimulus presentation apparatus of this invention. The block diagram which shows one Embodiment of the brain function measurement using the stimulus presentation apparatus of this invention. The structural example of a stimulus presentation apparatus user interface part. The main screen of the stimulus presentation device user interface. Presentation pattern not selected. The main screen of the stimulus presentation device user interface. Presenting pattern selected. The main screen of the stimulus presentation device user interface. Presenting pattern selected. The main screen of the stimulus presentation device user interface. Version illustrating the measurement site and presentation pattern. Presenting pattern selected. External input / output setting screen. Detailed parameter setting screen for RS232C input / output. File editing method selection screen. Input screen for a new presentation pattern file name to be created. An input screen for a presentation pattern file name created based on an existing presentation pattern. Selection screen for existing presentation pattern files to be edited. Presentation pattern file creation / edit screen. Random stimulus setting screen. Response dependent stimulus setting screen. Setting screen for brain activity dependent stimuli. The block diagram of a biological light measuring device. The example of a screen which sets a stimulus presentation timing from a test subject's state.

Explanation of symbols

101 ... Measurer's user interface, 102 ... Stimulus presentation device, 103 ... Display for image presentation, 104 ... Speaker for voice presentation, 105 ... Vibration box for tactile stimulus presentation, 106 ... Brain function measurement device, 107 ... Brain function signal Processing device, 108 ... Subject response processing device,
401 ... main screen, 402 ... file editing screen, 403 ... input / output setting screen, 404 ... random stimulus setting screen, 405 ... response-dependent stimulus setting screen, 406 ... brain activity signal-dependent stimulus setting screen,
501 ... Start signal setting menu, 502 ... Stimulus type setting menu, 503 ... Sound output setting menu for correct / incorrect judgment, 504 ... Exit button, 505 ... External input / output setup button, 506 ... Pull-down menu for presentation pattern selection, 507 ... Check start button, 508 ... Output data file name input box, 509 ... Output data file reference button, 510 ... File edit button, 511 ... Stimulus content display section, 512 ... Visual list name display section, 513 ... Hearing List name display section, 514 ... presentation table name display section, 515 ... output file name display section, 516 ... present pattern start button, 517 ... present pattern stop button, 518 ... visual stimulus number display section during presentation, 519 ... response correct answer display unit, 520 ... display unit of auditory stimulus number being presented, 521 ... display unit of average response time, 522 ... content display unit of presentation table,
601 ... Stimulus type setting menu, 602 ... Presentation pattern selection pull-down menu, 603 ... Output data file name input box, 604 ... Visual list name display section, 605 ... Auditory list name display section, 606 ... Presentation table name display section , 607 ... Output file name display section, 608 ... Presentation pattern start button, 609 ... Display section of visual stimulus number being presented, 610 ... Display section of auditory stimulus number being presented, 611 ... Contents display section of presentation table,
701 ... Display unit of visual stimulus number being presented, 702 ... Display unit of auditory stimulus number being presented, 703 ... Content display part of presentation table,
801 ... Pull-down menu for selection of presentation pattern, 802 ... Check start button, 803 ... Input box for output data file name, 804 ... Display part of measurement part suitable for the selected presentation pattern, 805 ... Start button for presentation pattern, 806 ... Presentation table content display section (illustrated), 807...
901 ... button setting unit for response 1, 902 ... button setting unit for response 2, 903 ... button setting unit for response 3, 904 ... button setting unit for response 4, 905 ... game pad serving as an input device for subject response, 906 ... Gamepad setting menu for subject response input, 907 ... OK button, 908 ... Cancel button, 909 ... RS232C input setup button, 910 ... RS232C output setup button, 911 ... RS232C input command setting menu, 912 ... RS232C I / O setting menu, 913 ... Main (measurer interface) screen resolution setting pull-down menu, 914 ... Stimulus presentation screen resolution setting pull-down menu, 915 ... Screen (multi-monitor) setting menu,
1001 ... Transfer rate setting section, 1002 ... Data length setting section, 1003 ... Stop bit setting section, 1004 ... Parity setting section, 1005 ... Port setting section, 1006 ... Flow control setting section, 1007 ... OK button , 1008 ... Cancel button,
1101 ... OK button, 1102 ... Cancel button,
1201 ... Input section for newly created presentation pattern name, 1202 ... OK button, 1203 ... Cancel button,
1301 ... Selection section for a presentation pattern as a base, 1302 ... Input section for a newly created presentation pattern name, 1303 ... OK button, 1304 ... Cancel button,
1401 ... selection part of the presentation pattern to be edited, 1402 ... OK button, 1403 ... cancel button,
1501 ... Display unit of selected stimulus type, 1502 ... Display unit of selected presentation pattern, 1503 ... Display unit and display setting unit of stimulus type to be main presentation, 1504 ... End button, 1505 ... Display of variable stimulus information and Selection part, 1506 ... Menu for creating a new presentation table from detailed patterns, 1507 ... Display part of presentation table name, 1508 ... Display part of stimulus list, 1509 ... Display part of presentation table, 1510 ... Contents of stimulus list Display unit, 1511 ... Editing part of the presentation table and stimulus list, 1512 ... Menu for updating, registering, deleting, reading and saving the edit result of the presentation table and stimulus list,
1601 ... End button, 1602 ... Random stimulus selection unit, 1603 ... Random presentation time setting menu, 1604 ... Stimulus list name display unit, 1605 ... Stimulus list content display unit, 1606 ... Random stimulus display unit, 1607 ... Random Candidate stimulus display section selected as a stimulus, 1608 ... Arrow button for selecting a random stimulus candidate stimulus, 1609 ... Random stimulus save / delete menu, 1610 ... Arrow button for selecting a post-random stimulus candidate stimulus, 1611 ... Post-random stimulus display section, 1612 ... Display section of candidate stimulus selected as post-random stimulus, 1613 ... Save post-random stimulus, delete menu,
1701 ... Subject response selection unit, 1702 ... Feedback control setting unit, 1703 ... Stimulus list name display unit, 1704 ... Stimulus list content display unit, 1705 ... Subject response dependent stimulus presentation time setting menu, 1706 ... Subject response Arrow buttons to select stimuli, 1707 ... Subject response stimulus display,
1801 ... Brain activity signal selection unit, 1802 ... Stimulus list name display unit, 1803 ... Stimulus list content display unit, 1804 ... Brain activity signal dependent stimulus presentation time setting menu, 1805 ... Brain activity signal dependent stimulus selection Arrow button, 1806 ... Display unit of brain activity signal dependent stimulus, 1901 ... Control device, 1902 ... Analog to digital converter, 1903 ... Lock-in amplifier, 1904 ... Lock-in amplifier, 1905 ... Oscillator, 1906 ... Oscillator, 1907 ... Light source, 1908 ... light source, 1909 ... light mixer, 1910 ... light detector, 1911 ... display, 2001 ... measurement scenery display screen, 2002 ... stimulus 1 presentation button, 2003 ... stimulus 2 presentation button, 2004 ... stimulus 3 presentation button, 2005 ... Stimulus 1 presentation button, 2006… End button.

Claims (8)

A stimulus presentation means for presenting a sensory stimulus to the subject;
A brain function measuring device for measuring the brain function of the subject;
A setting unit for editing the type or timing of the stimulus presented by the stimulus presenting means in a table or a table or a graph ;
A response processing device for recognizing a response of the subject to the stimulus;
The stimulation display device for brain function measurement , wherein the setting unit can set a type of stimulation that is automatically selected according to a response result of the subject recognized by the response processing device. The brain function measurement stimulus presentation device according to claim 1, wherein the setting unit includes a selection unit that selects whether or not to randomly give a type and / or timing of a stimulus to the subject. The setting unit gives the subject the type and / or timing of stimulation 1) randomly, or 2) depending on the response result of the subject recognized by the response processing device,
3. The stimulation presentation device for brain function measurement according to claim 1, further comprising a selection unit that selects whether to give the brain function measurement result of the subject by the brain function measurement device. The stimulation presentation device for brain function measurement according to any one of claims 1 to 3, further comprising a storage unit that stores the stimulus edited by the setting unit. 5. The brain function measurement device according to claim 1, wherein the setting unit includes a start signal selection unit that selects a signal for the stimulus presentation device to start stimulus presentation to the subject. Stimulus presentation device. The brain function measuring device measures the brain function of the subject by irradiating the subject's head with light and detecting the light propagating through the subject's head. To 5. The stimulus presentation device for brain function measurement according to any one of 1 to 5. The brain function measurement stimulus presenting apparatus according to claim 1, wherein the setting unit can display or set a brain function measurement parameter in accordance with the set type of stimulus. The stimulation presentation device for brain function measurement according to claim 7, wherein the parameter is a measurement site, a size of the measurement site, a wavelength of light used for brain function measurement, or a sampling period of brain function measurement.

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