JP2018158042A - Information processing device, information processing method, and information processing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire an index by which to quantitatively evaluate a brain activity state.SOLUTION: An information processing device includes: a storage part for storing a first detection value at which a blood flow rate in the head of a user is detected when the user performs a control task, a second detection value at which a blood flow rate in the head of the user is detected when the user performs a unit task with a larger cognitive load than that of the control task, and a third detection value at which a blood flow rate in the head of the user is detected when the user performs an object task; and an arithmetic part for calculating an index value of the object task with a difference between a first measurement value based on the first detection value and a second measurement value based on the second detection value as a reference, using a third measurement value based on the third detection value.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an information processing apparatus, an information processing method, and an information processing program.

  Conventionally, a head-mounted device called a headset is provided with a near-infrared irradiation unit and a near-infrared detection unit, detects changes in blood flow on the brain surface, and processes the detected data with a data processing device. A measurement system that acquires information indicating the activity state of the brain is provided.

JP 2013-17734 A

  The brain activity state when various tasks (work, action) are performed for a plurality of users (subjects) is measured. It is considered that the brain activity state when performing a certain task (work, action) is influenced by various properties included in the task, user attributes, and the like. However, since there is no index for quantitatively evaluating the brain activity state, it is difficult to compare the brain activity state between the past, the present, and the user.

  An object of this invention is to obtain the parameter | index which evaluates a brain activity state quantitatively.

  In order to solve the above problems, the following means are adopted.

That is, the first aspect is
A first detection value obtained by detecting a blood flow rate of the user's head when the user performs a control task, and the user's head when the user performs a unit task having a larger cognitive load than the control task. A storage unit for storing a second detection value for detecting the blood flow rate of the part and a third detection value for detecting the blood flow rate of the user's head when the user performs the target task;
Using the third measurement value based on the third detection value, the index of the target task based on the difference between the first measurement value based on the first detection value and the second measurement value based on the second detection value An arithmetic unit for calculating a value;
Is an information processing apparatus.

  An aspect of the disclosure may be realized by executing a program by an information processing device. That is, the disclosed configuration can be specified as a program for causing the information processing apparatus to execute the processing executed by each unit in the above-described aspect, or a computer-readable recording medium on which the program is recorded. Further, the disclosed configuration may be specified by a method in which the information processing apparatus executes the process executed by each of the above-described units. The configuration of the disclosure may be specified as a system including an information processing apparatus that performs the processing executed by each of the above-described units.

  The step of describing the program includes processes that are executed in parallel or individually even if they are not necessarily processed in time series, as well as processes that are executed in time series in the described order. Some of the steps describing the program may be omitted.

  According to the disclosed technique, an index for quantitatively evaluating the brain activity state can be obtained.

FIG. 1 is a diagram illustrating a configuration involved in information processing of the measurement system according to the embodiment. FIG. 2 is a diagram illustrating a configuration example of the head-mounted device. FIG. 3 is a diagram illustrating a configuration example of the arithmetic device. FIG. 4 is a diagram illustrating an example of an operation flow of the measurement system according to the embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. The configuration of the embodiment is an exemplification, and the configuration of the invention is not limited to the specific configuration of the disclosed embodiment. In carrying out the invention, a specific configuration according to the embodiment may be adopted as appropriate.

Embodiment
(Configuration example)
FIG. 1 is a diagram illustrating a configuration related to information processing of a measurement system according to an embodiment of the present invention. This measurement system detects measurement data (also referred to as a detection value) indicating a change in blood flow from the user's head, and acquires brain activity information (brain activity waveform) indicating the activity state of the user's brain.

  As shown in FIG. 1, the measurement system includes a head-mounted device 10 and a calculation device 20.

FIG. 2 is a diagram illustrating a configuration example of the head-mounted device. The head-mounted device 10 includes a control unit 11, a wireless communication unit 13, and a pair of sensors 115 and 125 in terms of information processing. The control unit 11 controls measurement and communication of the head-mounted device 10. The control unit 11 includes, for example, a processor such as a CPU (Central Processing Unit) or DSP (Digital Signal Processor) and a memory, and executes processing using a computer program, firmware, or the like that is executed on the memory. . However, the control unit 11 may be a dedicated hardware circuit, an FPGA (Field Programmable Gate Array), or the like that activates the wireless communication unit 13 and the sensors 115 and 125 and executes cooperation processing with each component. In addition, the control unit 11
A CPU, a DSP, a dedicated hardware circuit, etc. may be mixed.

  The head mounting device 10 has a structure in which a headband is wound around a user's head and fixed to the user's head by fastening a fixing member.

The wireless communication unit 13 is connected to the control unit 11 and the sensors 115 and 125 through a predetermined interface. However, the wireless communication unit 13 may be configured to acquire data from the sensors 115 and 125 via the control unit 11. The wireless communication unit 13 communicates with the arithmetic device 20 via the network N1. The network N1 is a network work according to standards such as Bluetooth (registered trademark), wireless LAN (Local Area Network), and ZigBee (registered trademark). The wireless communication unit 13 is an example of a transfer unit. However, in this measurement system, there is no limitation on the standard of the wireless interface of the wireless communication unit 13.

  At the time of communication on the network N1, an identifier for identifying the head-mounted device 10 is embedded in the header portion of the communication header or the user data portion (payload portion) in the communication data, so that the computing device 20 is the user (subject ).

In this measurement system, instead of the wireless communication unit 13 or the wireless communication unit 13
In addition, a communication unit that performs wired communication may be provided. That is, the head-mounted device 10 and the arithmetic device 20 may be connected by a wired communication interface. In this case, the interface for wired communication is not limited, and various interfaces such as USB (Universal Serial Bus), PCI Express, etc. can be used according to the use of the measurement system.

  The sensors 115 and 125 both irradiate the head with near infrared rays, receive near infrared rays that are partially absorbed and scattered near the cerebral cortex of the brain, and convert them into electrical signals. The cerebral cortex of the brain has a different blood flow rate, for example, depending on the brain activity state. As a result, in each part of the cerebral cortex, the amount of hemoglobin bound to oxygen in the blood and the amount of hemoglobin not bound to oxygen change. Due to a change in the amount of hemoglobin, a change in the amount of oxygen, or the like, the near-infrared absorption characteristic or scattering characteristic in the vicinity of the cerebral cortex changes. The sensors 115 and 125 convert the near-infrared light whose light amount changes according to the change in the near-infrared absorption rate or the change in the transmittance according to the state of blood flow in the vicinity of the cerebral cortex into an electrical signal and outputs it. The sensors 115 and 125 are an example of detection means.

The sensors 115 and 125 include, for example, a near-infrared light source that emits near-infrared light and a light-receiving unit that receives near-infrared light. The near infrared light source is, for example, an LED (Light Emitting Diodes), an infrared lamp, or the like. The light receiving unit includes a photoelectric element such as a photodiode or a phototransistor, an amplifier, and an AD (Analog Digital) converter. Note that the near-infrared light source and the light receiving unit may not be provided in pairs. For example, a plurality of light receiving units may be provided for one near infrared light source.

FIG. 3 is a diagram illustrating a configuration example of the arithmetic device. The computing device 20 obtains near infrared absorption or transmittance change data near the cerebral cortex of the user from the head-mounted device 10, and performs various information processing related to the activity state of the user's brain. Provide services that include. The arithmetic device 20 is an example of an information processing device (computer). The computing device 20 is a PC (Personal Computer), a smartphone, a mobile phone, a tablet terminal, a car navigation device, a PDA.
This can be realized by using a dedicated or general-purpose computer such as (Personal Digital Assistant) or an electronic device equipped with the computer. The computing device 20 can be installed in, for example, a fitness club or a learning school.

  The computing device 20 includes a CPU 21, a memory 22, a wireless communication unit 23, a public line communication unit 24, a display unit 25, an operation unit 26, an output unit 27, an imaging unit 28, a positioning unit 29, It has a physical sensor unit 2A. The CPU 21 executes processing as the arithmetic device 20 by a computer program that is executed in the memory 22 so as to be executable. The processing as the arithmetic device 20 is, for example, a service including various information processing related to the activity state of the user's brain. The CPU 21 that executes such a computer program is an example of a calculation unit.

  The memory 22 stores a computer program executed by the CPU 21 or data processed by the CPU 21. The memory 22 may include volatile memory and non-volatile memory. The memory 22 is an example of a storage unit.

  The wireless communication unit 23 is the same as the wireless communication unit 13 of the head-mounted device 10. The wireless communication unit 23 is an example of a receiving unit. In addition, the arithmetic device 20 may include a communication unit that performs wired communication instead of the wireless communication unit 23 or together with the wireless communication unit 23.

The public line communication unit 24 communicates with a server or the like on the network via an upper network (not shown). The network is a public line network, for example, a mobile phone network. When the network is a mobile phone network, the public line communication unit 24 connects to the network via a base station of the mobile phone network. However, the network may be a network including the access network to the communication device of the Internet service provider and the Internet. An access network to a communication device of an Internet connection company is, for example, an optical network provided by a communication carrier, ADSL (Asymmetric Digital Subscriber Line), or the like. The network is an example of a public wireless network. The public line communication unit 24 is an example of public wireless communication means. However, in this measurement system, the network is not limited to a public network, for example, a private network such as a LAN (Local Area Network), a private line such as a company, an operator, a government office, a school, a research institution, or a VPN (Virtual Private network
) Or the like. Hereinafter, companies, businesses, government offices, schools, research institutions, etc. are also referred to as companies.

  The display unit 25 is, for example, a liquid crystal display, an EL (Electro-Luminescence) panel, and the like, and displays output information from the CPU 21. The operation unit 26 is, for example, a push button, a touch panel, or the like, and accepts a user operation. The output unit 27 is, for example, a vibrator that outputs vibration, a speaker that outputs sound or sound, and the like. The imaging unit 28 is a camera including a solid-state imaging element, for example. As the solid-state image sensor, a CCD (Charge-coupled device) image sensor, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or the like can be used.

The positioning unit 29 is a GPS (Global Positioning System) receiver, for example,
Receives radio waves from the satellite and calculates the current position (latitude, longitude, etc.), time, etc. However, the positioning unit 29 is not limited to the one having a GPS receiver. For example, when the public line communication unit 24 is a mobile phone network, the positioning unit 29 may perform positioning based on the distance from the mobile phone base station.

  The physical sensor unit 2A is, for example, an acceleration sensor or an angular acceleration sensor. However, the physical sensor unit 2A may be a temperature sensor, a humidity sensor, an atmospheric pressure sensor, or a water pressure sensor.

<Operation example>
An operation example of the measurement system of the present embodiment will be described.

  FIG. 4 is a diagram illustrating an example of an operation flow of the measurement system of the present embodiment. Each of the head-mounted devices 10 of the measurement system of the present embodiment is mounted on the user's (subject) 's head, and is in a state where the brain activity state (cerebral blood flow) can be measured. The head mounting devices 10 are each connected to the arithmetic device 20. It is assumed that the head mounting device 10 has already been calibrated.

  In S101, the computing device 20 causes the user wearing the head-mounted device 10 to perform a control task for a predetermined time. The control task is a task (work, action) that is a base of the user's brain activity. The control task is a task for determining a baseline of brain activity. As a control task, it is desirable that the dorsolateral prefrontal cortex hardly activates (activate) and that the user's cognitive state can be unified. The dorsolateral prefrontal cortex is said to play a role in integrating cognitive functions and is responsible for overall human cognition. By measuring the activity of the dorsolateral prefrontal cortex, comprehensive brain activity can be evaluated.

The control task may be to prevent the user from doing anything, but since the waveform of the brain activity state when nothing is done is often not stable, it is desirable to cause some task to be performed. When performing the control task, the arithmetic unit 20 displays predetermined information on the display unit 25, causes the output unit 27 to output predetermined sound, and causes the user to perform the control task. In addition, the arithmetic unit 20 outputs information and sound as a cue to start and end of the control task through the display unit 25 and the output unit 27. The arithmetic unit 20 may receive an input of an operation of a start signal and an end signal of the control task by a user or the like through the operation unit 26.

  Specific examples of the control task include a button press task, an object tracking task, a meditation task, and a finger tap task. The button pressing task is a task of pressing a button in accordance with a blinking mark displayed on the screen. The object tracking task is a task for visually tracking a randomly moving mark displayed on the screen. The meditation task is a task of breathing according to some rhythm. The finger tap task is a task of tapping the thumb and index finger at an arbitrary pace. By using these as control tasks, the baseline of the detected value of the brain activity state can be stabilized. The control task is not limited to these.

  When the user is performing a control task, the computing device 20 causes the head-mounted device 10 to measure the brain activity state of the user. The brain activity state is measured at a predetermined sampling frequency. The head-mounted device 10 measures the brain activity state of the user using the sensors 115 and 125, and transmits a detection value indicating the brain activity state to the arithmetic device 20 via the wireless communication unit 13. When the arithmetic device 20 receives a detection value (brain activity waveform) indicating a brain activity state from the head-mounted device 10 via the wireless communication unit 23, the arithmetic device 20 stores it in a storage unit such as the memory 22. Here, the detected value may be the measured value itself, information obtained by processing the measured value so as to be easily transmitted to the arithmetic unit 20, or information obtained by collecting the values measured in a certain period. But you can. The detected value may be a value based on a value obtained by measuring the blood flow change of the head by the head-mounted device 10. The detection value indicating the brain activity state is stored as time series data together with time information, an identifier of the control task, and an identifier of the user. The arithmetic unit 20 may always acquire a detection value indicating a brain activity state as a measurement result, and extract a detection value indicating a brain activity state while performing the control task. The detected value (brain activity waveform) is, for example, a temporal change in cerebral blood flow or a time derivative of cerebral blood flow.

  In S102, the computing device 20 causes the user wearing the head-mounted device 10 to perform a unit task for a predetermined time. The predetermined time for performing the unit task may be different from the predetermined time for performing the control task. The unit task is a task that gives the brain a load corresponding to one unit of the index value in the brain activity. As a unit task, it is desirable that the cognitive load is constant regardless of the user, and the fluctuation of the cognitive load due to the user's familiarity with the task is small. Since the cognitive load is constant regardless of the user, even if there is a difference in the magnitude of the brain activity during the unit task, it is considered that those brain activities occurred under the same cognitive load. By using a task with a small change in cognitive load due to user's task familiarity, it is possible to prevent the relationship between the index and the cognitive load from being broken. Moreover, as a unit task, a task that widely activates the dorsolateral prefrontal cortex is desirable regardless of the user. In the measurement of the brain activity state by the head-mounted device 10, the position of the sensor is shifted every time the head-mounted device 10 is worn on the user, so that the measured brain region is also shifted. By widely activating the dorsolateral prefrontal cortex, it is possible to reduce the influence of the sensor position shift of the head-mounted device 10. When performing the unit task, the arithmetic unit 20 displays predetermined information on the display unit 25, causes the output unit 27 to output predetermined sound, and causes the user to perform the unit task. In addition, the arithmetic unit 20 outputs information and sound as a cue for the start and end of the unit task through the display unit 25 and the output unit 27. The arithmetic unit 20 may accept input of operations for starting and ending a unit task by a user or the like through the operation unit 26.

Specific examples of unit tasks include word storage / recall tasks, simple calculation tasks, word attribute determination tasks, Stroop tasks, N-back tasks, and the like. The word storage / recall task is a task that stores a predetermined number (for example, ten) of words displayed continuously and recalls them as accurately as possible. The simple calculation task is a task for performing a single digit arithmetic operation. The word attribute determination task is a task for determining whether or not attributes of two words displayed thereafter match in accordance with a rule presented in advance. The Stroop task is a task in which a word indicating a color (for example, red or blue) is presented and the color of the character in which the word is written is answered or the meaning of the word is answered. The N-back task is a task for storing continuously presented numbers and determining whether or not the N-numbered number matches the currently-presented number. The unit task is a task that places a certain load on the user's brain. The unit task load is larger than the control task load. The unit task is not limited to these. By selecting appropriate control tasks and unit tasks that meet the above conditions, it is possible to calculate an index value that is not affected by differences in users.

  When the user is performing the unit task, the arithmetic device 20 causes the head-mounted device 10 to measure the brain activity state of the user. The measurement of the brain activity state when the unit task is performed is the same as the measurement of the brain activity state when the control task is performed.

  In S103, the arithmetic unit 20 causes the user wearing the head-mounted device 10 to perform the target task for a predetermined time. The predetermined time for performing the target task may be different from the predetermined time for performing the control task and the predetermined time for performing the unit task. The target task includes, for example, video viewing, game play, music appreciation, exercise, eating and drinking, examination, meditation, sleep, yoga, application play, and the like. The target task may be a specific action in a specific application. Applications include, for example, brain training applications. The target task is not limited to these. For example, when performing the video viewing, the computing device 20 displays the video on the display unit 25 and causes the output unit 27 to output the sound associated with the video to allow the user to view the video. In addition, when playing the game, the arithmetic unit 20 causes the display unit 25 and the output unit 27 to output a game image or sound, and causes the user to operate the game using the operation unit 26, thereby playing the game. Let's play. In addition, the arithmetic unit 20 outputs a start signal and an end signal of a predetermined exercise as a target task through the display unit 25 and the output unit 27 by an image and sound. The arithmetic unit 20 may receive input of operations for starting and ending a predetermined exercise as a target task through the operation unit 26.

  When the user is performing the target task, the arithmetic device 20 causes the head-mounted device 10 to measure the brain activity state of the user. The measurement of the brain activity state when the target task is performed is the same as the measurement of the brain activity state when the control task is performed.

  In S104, the arithmetic unit 20 calculates the index value of the target task. The index value is used to quantitatively evaluate the amount of brain activity (activation amount) during execution of any task, based on the difference between the measurement value during execution of the control task and the measurement value during execution of the unit task. Value. The CPU 21 of the arithmetic unit 20 calculates an average value (time average value) of the detected values of the brain activity state measured when each task is performed. Here, the time average value of each task is a measured value of each task. The measured value is a value indicating the degree of brain activity, and the larger the measured value, the more active the brain is. The CPU 21 calculates the index value of the target task based on the following formula.

The index value of the target task represents the degree of load of the target task with respect to the load of the unit task, assuming that the brain activity state is very low when the control task is executed. The larger the index value, the greater the load on the target task relative to the unit task. Here, according to this equation, the index value of the unit task is 1.

  The CPU 21 stores the calculated index value of the target task in a storage unit such as the memory 22. Further, the CPU 21 may output the calculated index value through the display unit 25, the output unit 27, and the like.

  The order of S101, S102, and S103 may be changed. For example, the user may be caused to perform the target task first.

(Operation and effect of the embodiment)
In the measurement system of the present embodiment, the computing device 20 measures the brain activity state when the user is performing the control task, the unit task, and the target task by the head-mounted device 10. The computing device 20 acquires the brain activity state transmitted from the head-mounted device 10. The computing device 20 calculates an index value of the target task based on the measured values of the brain activity state of each task. The index value is standardized by the measurement value of the control task and the measurement value of the unit task.

  Even when a task that is a cognitive load is executed, the measured values of the brain activity state may differ due to individual differences or differences in the mounting position of the head-mounted device 10. By using the index value of the present embodiment, it is possible to compare the task load between the present and the past or between users. The index value normalized by the unit task measurement value and the control task measurement value is a quantitative index. In other words, the index value of the target task obtained here is a comparison between the detected values of the brain activity state between the past and the present, between users, the influence of variation due to the mounting position of the head mounting device 10, etc. can do. Therefore, the cognitive load when an arbitrary target task is executed can be quantitatively evaluated.

10 Head-mounted device
11 Control unit
13 Wireless communication unit
115 sensors
125 sensors
20 arithmetic unit
21 CPU
22 memory
23 Wireless communication unit
24 Public Line Communication Department
25 Display section
26 Operation unit
27 Output section
28 Imaging unit
29 Positioning Department
2A physical sensor

Claims (4)

A first detection value obtained by detecting a blood flow rate of the user's head when the user performs a control task, and the user's head when the user performs a unit task having a larger cognitive load than the control task. A storage unit for storing a second detection value for detecting the blood flow rate of the part and a third detection value for detecting the blood flow rate of the user's head when the user performs the target task;
Using the third measurement value based on the third detection value, the index of the target task based on the difference between the first measurement value based on the first detection value and the second measurement value based on the second detection value An arithmetic unit for calculating a value;
An information processing apparatus comprising: The first measurement value is a time average value of the first detection value;
The second measurement value is a time average value of the second detection value,
The information processing apparatus according to claim 1, wherein the third measurement value is a time average value of the third detection value. A first detection value obtained by detecting a blood flow rate of the user's head when the user performs a control task, and the user's head when the user performs a unit task having a larger cognitive load than the control task. A second detection value for detecting the blood flow volume of the part and a third detection value for detecting the blood flow volume of the user's head when the user performs the target task;
Using the third measurement value based on the third detection value, the index of the target task based on the difference between the first measurement value based on the first detection value and the second measurement value based on the second detection value Calculate the value,
An information processing method that executes things. A first detection value in which a computer detects a blood flow rate of the user's head when the user performs a control task, and the user when the user performs a unit task having a larger cognitive load than the control task A second detection value for detecting a blood flow volume of the head of the user and a third detection value for detecting a blood flow volume of the head of the user when the user performs a target task;
Using the third measurement value based on the third detection value, the index of the target task based on the difference between the first measurement value based on the first detection value and the second measurement value based on the second detection value Calculate the value,
An information processing program for executing things.

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