Cognitive capacity measurement device and method

Since the present invention contributes to the study of brain function, the present invention relates to a cognitive ability measuring device and a cognitive ability measuring method for measuring a cognitive ability peculiar to each individual.

Conventionally, various intelligence tests and aptitude tests have been devised as methods for obtaining a measure of human aptitude and ability as shown in Patent Documents 1 and 2, and are used for education, employment, welfare, and the like. ..<patcit num="1"><text>Special fair 06-046989</text></patcit><patcit num="2"><text>Patent 2506023</text></patcit>

<p> However, since these methods do not focus on the micromechanism of the brain, it is possible to measure individual differences, but the results obtained for each individual reflect what kind of action the brain has. I couldn't know if it was there, and because of that, I couldn't explain its legitimacy from the aspect of brain function.</p><p> On the other hand, the present inventor presents various images subjected to predetermined processing to a plurality of subjects and measures the time required to perceive the contents, and the ranking according to the perceived time of each subject is not related to the type of image. By discovering the fact that there was almost no change and at the same time there was almost no change in the ranking of each image according to the perception time regardless of the subject, and further scrutinizing the experimental data, the perception time of each image was changed. It was found that the frequency distribution of the number of subjects with respect to the logarithm can be approximated to a normal distribution, and the standardized score of each subject is almost constant regardless of the type of image. Then, we found that the cognitive ability peculiar to each subject and the difficulty level peculiar to each image can be quantified into two variables, the cognitive ability score and the difficulty level parameter, respectively, and that a predetermined relational expression holds between these and the perception time. Revealed.</p><p> Furthermore, the present inventor presents that the cognitive ability score and the difficulty parameter obtained by the above method reflect the brain function because this relational expression becomes the same as the relational expression of the chemical reaction rate by a simple modification. It is considered to be a thing, and it is suggested that the analogy with thermodynamics may provide new knowledge about the mechanism of the brain.</p><p> The present invention utilizes this to establish a method for measuring cognitive ability to restore original information from incomplete information, which can explain the correspondence with brain function, and further utilize this result for research on brain function. In the future, the aim is to contribute to the selection of education suitable for each individual, the judgment of suitability, and the early detection of diseases related to cognitive function such as Alzheimer-type dementia.</p>

<p> That is, the recognition ability measuring device according to the present invention has a function of displaying a deteriorated image, which is an image in which information for perceiving the subject is deteriorated by performing predetermined processing on an original image having a meaningful subject. It is an image display unit, a reception unit that receives the perception of the subject from the subject and outputs a reception signal, and a time required for the subject to perceive the subject by receiving the reception signal from the reception unit. A perception time calculation unit that calculates the perception time, a difficulty information storage unit that stores difficulty information that is information on the difficulty of the deteriorated image due to subject perception, and the perception calculated by the perception time calculation unit. A cognitive ability calculation unit that calculates a cognitive ability score, which is an index that quantifies the cognitive ability of each subject, by performing a predetermined calculation using the time and the difficulty level information stored in the difficulty level information storage unit. Equipment<u style="single">Eh, the image display unit further has a function of displaying the original image to the subject, and the subject perceives the subject after the image display unit displays the deteriorated image in the perception time calculation unit. From the deterioration image required time, which is the time required for the reception unit to accept the fact, the reception unit indicates that the subject perceives the subject after the image display unit displays the corresponding original image. The perceived time is calculated by subtracting the time required for the original image, which is the time required for acceptance.</u>It is characterized by that. Here, the meaningful subject means a subject that the subject can express in words.</p><p> With such a device, the cognitive ability score of each individual can be measured with a simple configuration, and the result can be explained in correspondence with the brain function. Furthermore, this result can be used for research on brain function, and in the future, it can be used for selection of education suitable for each individual, judgment of suitability, early detection of diseases related to cognitive function such as Alzheimer's dementia, and the like.<u style="single">Further, since the perceived time is obtained by subtracting the time required for the original image from the time required for the deteriorated image, factors such as the physical reflection speed of the subject can be removed, which is preferable.</u></p><p> Experiments have confirmed that the frequency distribution of the number of subjects with respect to the logarithm of the perceived time of degraded images obtained from a large number of subjects closely approximates the normal distribution, and the standardized score of the subjects on this normal distribution is the cognitive ability of the subjects. It is thought that it represents. Further, since it is considered that the recognition ability is higher as the perception time is shorter, it is preferable to use a numerical value obtained by reversing the sign of the standardized score as the recognition ability score because it is easy to understand.</p><p> Since the cognitive ability score is unique to an individual, in order to effectively utilize this cognitive ability score for education, etc., a cognitive ability memory unit that stores the cognitive ability score in association with the subject identifier is further provided. preferable.</p><p> In order to improve the reliability of the measurement result, the image display unit can selectively display a plurality of types of images, and the recognition ability calculation unit can use the perceived time obtained for each of the deteriorated images. It is desirable to calculate the cognitive ability score.</p><p> As a specific embodiment, it is preferable that the output unit further includes an output unit that outputs the recognition ability score.</p><p> As the deteriorated image, a binarized version of the original image is preferable. Such images can be easily and mass-produced, and the difficulty level can be adjusted by adjusting the threshold value.</p><p> In addition, in order to calculate the difficulty level information of each deteriorated image used for measuring the recognition ability, an image display unit having a function of displaying the deteriorated image to the subject and a receptionist who perceives the subject from the subject are accepted. The reception unit that outputs a signal, the perception time calculation unit that receives the reception signal from the reception unit and calculates the perception time that is the time required for the subject to perceive the subject, and the perception time calculation unit. A perceptual time information storage unit that stores perceived time information, which is information about the perceived time in a plurality of calculated subjects, and the perceived time information stored in the perceived time information storage unit are acquired to obtain the perceived time information. A difficulty measuring device for a deteriorated image provided with a difficulty information calculation unit that calculates difficulty information which is information on the difficulty of the deteriorated image due to subject perception by approximating the distribution form with a predetermined function. It may be used.</p><p> Experiments have confirmed that the frequency distribution of the number of subjects with respect to the logarithm of the perceived time of the degraded images obtained from a large number of subjects closely approximates the normal distribution. It can be information. Further, since it is known from experiments that the standard deviation of this normal distribution can be approximated by a linear function of the mean value, this mean value can be used as a difficulty parameter. In this way, the difficulty level of the deteriorated image can be expressed by one variable, and the difficulty level of each deteriorated image can be easily compared.</p><p> Since the difficulty level information is unique to each deteriorated image, in order to effectively utilize this difficulty level information for recognition ability measurement, a difficulty level information storage unit that stores the difficulty level information in association with the deteriorated image identifier is further added. Those provided are preferable.</p>

<p> According to the present invention, it is possible to measure the cognitive ability to restore the original information from incomplete information. Moreover, since the cognitive ability score obtained by this method can explain the correspondence with the brain function, this result can be useful for the study of the brain function. Furthermore, in the future, it will be possible to contribute to the selection of education suitable for each individual, the judgment of suitability, and the early detection of diseases related to cognitive function such as Alzheimer's dementia.</p>

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The corresponding parts in each embodiment are designated by the same reference numerals.

&lt;First Embodiment&gt;

In this embodiment, the difficulty parameter peculiar to the image is obtained from the frequency distribution of the number of subjects with respect to the logarithm of the subject perception time of the deteriorated image. FIG. 1 is a schematic device configuration diagram showing a difficulty level measuring device according to the present embodiment. This difficulty measuring device displays an original image having a meaningful subject and a deteriorated image which is an image obtained by performing predetermined processing on the original image to deteriorate the information for perceiving the subject for a predetermined time. It includes an image display unit 1, a reception unit 2 that receives the subject's perception of the subject, and an information processing device 3 that receives a reception signal from the reception unit 2 and performs predetermined information processing based on the reception signal. ..

The image display unit 1 is configured by using, for example, a display 104, and in this embodiment, it is communicably connected to the information processing device 3, and the original image or the deterioration is given by a command from the information processing device 3. It displays one image. The original image and the deteriorated image are as shown in FIG. 2, for example.

As shown in FIG. 1, for example, the reception unit 2 uses a push button type switch, and outputs a reception signal when the subject presses the switch. The subject answered the subject before pressing the switch, and if the answer was incorrect, the operator invalidated the answer.

As shown in FIG. 3, the information processing device 3 includes a storage device such as a volatile memory and an HDD 102 in addition to the CPU 101, and further, an input / output interface for connecting to an input unit 103 such as a mouse or a keyboard and the display 104. It has 105 mag. Then, by installing a predetermined program in the storage device and cooperating with the CPU 101 and peripheral devices based on the program, the information processing device 3 uses the subject information acquisition unit as shown in the functional block diagram in FIG. 11. Functions as subject information storage unit D1, image information storage unit D2, image display control unit 12, perceived time calculation unit 13, perceived time information storage unit D3, difficulty information calculation unit 14, difficulty information storage unit D4, etc. It is configured to demonstrate.

It is not necessary that the image display unit 1, the reception unit 2, and the information processing device 3 are physically provided separately, and for example, a laptop computer or the like may be used to integrally configure them. Absent.

Each part will be described in detail.

The subject information acquisition unit 11 receives subject information such as the subject's age, gender, and name, assigns an identifier (number, etc.) for identifying the subject to the received subject information, and assigns an identifier (number, etc.) to the received subject information (see FIG. 5). It is stored in the subject information storage unit D1 provided in the predetermined area of.

The image information storage unit D2 is provided in a predetermined area of the storage device, and stores image information for displaying each image as shown in FIG. 2 in association with an image identifier for identifying each image. (See Figure 6).

The image display control unit 12 controls the image display unit 1 with a control signal based on the image information stored in the image information storage unit D2 to display each image, and further outputs a display signal to the perception time calculation unit 13. Is what you do.

The perception time calculation unit 13 calculates the time required for the subject to see the deteriorated image and perceive the subject. In the present embodiment, the time required from receiving the display signal from the image display unit 12 and the reception signal from the reception unit 2 and displaying the image until the subject presses the switch is the deteriorated image and its original image. Was measured, and the value obtained by subtracting the time required for the original image from the time required for the deteriorated image was calculated as the perceived time. This is to remove factors such as the physical reflection speed of the subject. Each calculated perception time is associated with the image identifier and the subject identifier and stored in the perception time information storage unit D3 in a predetermined format (see FIG. 7).

The difficulty information calculation unit 14 receives the perceived time information from the perceived time information storage unit D4, and fits a normal distribution to the frequency distribution of the number of subjects with respect to the logarithmic value of the perceived time for each image. And the standard deviation σ is output as difficulty level information.

Here, the normal distribution is expressed by the following formula 1.

<maths num="1"><img file="JP4635179B2_D0001.tif" /></maths>

Since it has been found from experiments by the present inventor that the standard deviation σ can be approximated to a linear function of the mean value m, only the mean value m may be output as difficulty level information. The present inventor names this average value m as a difficulty parameter. This difficulty parameter corresponds to the perception time in the logarithmic time when half of the subjects perceive the subject, and is an index showing the recognition difficulty of each deteriorated image.

The difficulty level information storage unit D4 stores the difficulty level information calculated by the difficulty level information calculation unit 14 in association with the image identifier (see FIG. 8).

Next, the operation of this device will be briefly described with reference to FIG.

First, the operator operates the input unit to input the subject information.

The subject information acquisition unit 11 receives the subject information input in this way (step S1), and stores the subject information in the subject information storage unit D1 (step S2).

Next, one deteriorated image or original image is displayed on the image display unit 1 by the command of the image display control unit 12 (step S3).

On the other hand, the subject looks at the displayed image, answers the subject, operates the reception unit 2 and inputs that the subject is perceived (step S4).

The perceived time calculation unit 13 receives the display signal from the image display control unit 12 and the reception signal from the reception unit 2, acquires the required time, and stores the required time information storage unit (not shown) as the required time information such as the image identifier and the subject identifier. Memorize in association with (step S5). When the required time information is stored or the predetermined time limit elapses, steps S3 to S6 are repeated for all the images thereafter.

After the test for all images is completed, the perception time calculation unit 13 receives the required time information from the required time storage unit, and calculates the time obtained by subtracting the corresponding original image required time from the deteriorated image required time as the perceived time. (Step S7), it is stored as perceived time information in the perceived time information storage unit D3 (step S8).

The above test is repeated for all subjects. (Step S9)

After the test for all subjects is completed, the difficulty information calculation unit 14 receives the perceived time information from the perceived time information storage unit D3, and fits the frequency distribution of the number of subjects to the logarithm of the perceived time into a normal distribution for each image. For example, the mean value m and the standard deviation σ of this normal distribution are calculated as difficulty level information (step S10), and are stored in the difficulty level information storage unit D4 in association with the image identifier (step S11).

&lt;Second embodiment&gt;

This embodiment is configured to measure the cognitive ability of a subject using the difficulty level information calculated by the first embodiment. FIG. 10 is a schematic device configuration diagram showing the recognition ability measuring device in the present embodiment. Similar to the first embodiment, this recognition ability measuring device is an original image having a meaningful subject and a deteriorated image which is an image in which information for perceiving the subject is deteriorated by performing predetermined processing on the original image. Information processing that receives signals from the image display unit 1 that displays the image on the subject for a predetermined time, the reception unit 2 that accepts that the subject perceives the subject, and the reception unit 2 and performs predetermined information processing based on the signal. It is equipped with device 3.

Here, the subject in the present embodiment is not limited to the subject whose perception time was measured in order to calculate the difficulty level in the first embodiment, and may be any other subject. That is, this cognitive ability measuring device is effective even for subjects who have not contributed to the calculation of the difficulty level information, and the difficulty level information of the image is calculated by measuring the perception time of a sufficiently large number of subjects according to the first embodiment. Then, the cognitive ability of a new subject can be calculated using this image.

Since the configuration of the present embodiment has many parts in common with that of the first embodiment, the difference from the first embodiment is referred to with reference to FIG. 11 which is a functional block diagram of the information processing apparatus 3 in the present embodiment. Each part of the present embodiment will be described in detail focusing on the difficulty information storage unit D4, the recognition ability calculation unit 15, the recognition ability storage unit D5, and the output unit 16.

The difficulty level information storage unit D4 stores the difficulty level information calculated in the first embodiment in association with the image identifier.

The cognitive ability calculation unit 15 uses the following formula 2 for the subject's ability score s for the subject's perceptual time information stored in the perceived time information storage unit D3 and the difficulty level information stored in the difficulty information storage unit D4. Calculated by However, t is the perceived time, and m and σ are the difficulty information of the corresponding image, that is, the mean value and standard deviation of the normal distribution. This ability score is the inverted sign of a value commonly referred to as a standardized score. The standardized score indicates the position of the subject in the group of subjects who contributed to the calculation of the difficulty level information in the first embodiment. The present inventor has found through experiments that the standardized score of a certain subject is a substantially constant value regardless of the image. This indicates that this standardized score is an index of the cognitive ability of each subject. The sign of the standardized score is inverted to obtain the ability score because it is considered that the shorter the perception time, the higher the cognitive ability. For example, the ability score is 0 for subjects who are just on average. Since it is necessary to measure with a plurality of images in order to improve the reliability, in this case, the average value of the ability scores calculated for each image is used as the ability score of the subject.

<maths num="2"><img file="JP4635179B2_D0002.tif" /></maths>

The cognitive ability storage unit D5 stores the cognitive ability score calculated by the cognitive ability calculation unit 15 in association with the subject identifier (see FIG. 12).

The output unit 16 outputs the recognition ability score stored in the recognition ability storage unit D5 by displaying or printing.

Next, the operation of this device will be briefly described with reference to FIG.

Steps S1 to S8 are the same as those in the first embodiment. Further, in the case of calculating the cognitive ability of the subject whose perceptual time has already been measured in the first embodiment, the perceptual time information stored in the perceptual time information storage unit D3 may be used. It can be omitted.

The cognitive ability calculation unit 15 calculates the cognitive ability score of the subject from the perceived time information stored in the perceived time information storage unit D3 and the difficulty level information stored in the difficulty level information storage unit D4 (step S12), and recognizes the subject. It is stored in the ability storage unit D5 (step S13).

The output unit 16 outputs the recognition ability score (step S14).

In this way, the difficulty parameter of each image is calculated by the first embodiment, and the cognitive ability score of each subject is calculated by the second embodiment. The present inventor has shown from an analogy with thermodynamics that the difficulty parameters and cognitive ability scores thus obtained reflect brain function as follows. That is, the relational expression of the following mathematical formula 3 holds between the difficulty parameter and the cognitive ability score and the perception time. However, A and B are constants obtained from experiments.

<maths num="3"><img file="JP4635179B2_D0003.tif" /></maths>

If the reciprocal of this perception time t is taken as the perception velocity v and S = 1-Bs, the following equation 4 holds.

<maths num="4"><img file="JP4635179B2_D0004.tif" /></maths>

This equation has the same form as the equation of the chemical reaction rate expressed by the following equation 5. However, v0 is the initial velocity, ΔE is the activation energy, kB is the Boltzmann constant, and T is the temperature.

<maths num="5"><img file="JP4635179B2_D0005.tif" /></maths>

From the correspondence of these relational expressions, the present inventor considered that the cognitive ability score of the subject corresponds to the temperature, that is, how the number of microscopic states increases, and the difficulty parameter of each image corresponds to the activation energy. Furthermore, the present inventor thinks that the ability score may play a role like the temperature of the search activity in the information space (memory space), and by considering the analogy with thermodynamics, new knowledge about brain function can be obtained. It suggests the possibility of being sick.

As described above, according to the present invention, it is possible to quantify an individual's recognition ability and the difficulty level of an image by a simple method that has not been known so far, that is, measurement of the perception time of a deteriorated image. Moreover, since the relational expression that determines the perception time has been clarified, it has become possible to obtain new knowledge about brain function by further research using the present invention. The present invention contributes to the study of brain function, and in the future, it may be useful for selection of education suitable for each individual, judgment of suitability, early detection of diseases related to cognitive function such as Alzheimer's dementia, and the like. You can expect it.

Next, an experiment in which the difficulty parameter and the ability score are actually calculated according to the present invention will be described.

&lt;Experiment 1&gt; Calculation of difficulty parameters

The perception time of 91 subjects (20 to 24 years old) was measured using 90 sets of images, and the difficulty parameter of each image was calculated. FIG. 14 shows the cumulative frequency distribution of the subject with respect to the logarithm of the perceived time.

FIG. 15 shows some of the difficulty parameters of each image calculated by the experiment.

From the experimental results, the following equation 6 was obtained as an approximation that holds between the standard deviation σ and the difficulty parameter m.

<maths num="6"><img file="JP4635179B2_D0006.tif" /></maths>

&lt;Experiment 2&gt; Examination of calculated ability score

For the subjects for whom the ability score was calculated, the measured value of the perceived time was compared with the predicted value obtained from Equation 3 for the image of known difficulty that was not used in the calculation of the ability score. However, in Equation 3, A = 0.0305 seconds and B = 0.31 were used to obtain the predicted values of the perception time.

FIG. 16 shows the relationship between the predicted value and the measured value of the perceived time for two subjects having different ability scores. From the distribution of the straight line showing the predicted value and the point cloud showing the measured value shown in this figure, it can be shown that the prediction of the perception time is effective.

The present invention is not limited to the above embodiment. For example, with regard to the calculation of difficulty parameters and ability scores, data with extremely different tendencies can be appropriately rejected to improve accuracy.

Further, in the calculation of the difficulty level parameter, the median value may be used as the difficulty level parameter. The median is generally suitable because it is less affected by extreme values.

Others The present invention can be modified in various ways without departing from the spirit of the present invention.

<figref num="1">The schematic device block diagram of the difficulty measuring apparatus in 1st Embodiment of this invention.</figref><figref num="2">Explanatory drawing of the image to be displayed in the same embodiment.</figref><figref num="3">FIG. 6 is a schematic device configuration diagram showing an internal device configuration of the information processing device in the same embodiment.</figref><figref num="4">The functional block diagram of the information processing apparatus in the same embodiment.</figref><figref num="5">The data structure diagram which shows the internal data of the subject information storage part in the same embodiment.</figref><figref num="6">The data structure diagram which shows the internal data of the image information storage part in the same embodiment.</figref><figref num="7">The data structure diagram which shows the internal data of the perceived time information storage part in the same embodiment.</figref><figref num="8">The data structure diagram which shows the internal data of the difficulty information storage part in the same embodiment.</figref><figref num="9">The flowchart which shows the operation step of the difficulty measuring apparatus in the same embodiment.</figref><figref num="10">FIG. 6 is a schematic device configuration diagram of the difficulty level measuring device according to the second embodiment of the present invention.</figref><figref num="11">The functional block diagram of the information processing apparatus in the same embodiment.</figref><figref num="12">The data structure diagram which shows the internal data of the recognition ability storage part in the same embodiment.</figref><figref num="13">The flowchart which shows the operation step of the difficulty measuring apparatus in the same embodiment.</figref><figref num="14">Cumulative histogram showing the results of Experiment 1 performed using the difficulty measuring device of the first embodiment of the present invention.</figref><figref num="15">A part of the difficulty level parameters calculated as a result of Experiment 1 performed using the difficulty level measuring device of the first embodiment of the present invention.</figref><figref num="16">The figure which shows the result of the experiment 2 performed for confirming the accuracy of this invention.</figref>

1 Image display 2 Reception department 3 Information processing device 101 CPU 102 HDD 103 Input section 104 display 105 <u style="single">Input / output interface</u> 11 Subject information acquisition department 12 Image display control unit 13 Perception time calculation unit 14 Difficulty information calculation unit 15 Cognitive ability calculation unit 16 Output section D1 Subject information storage D2 Image information storage D3 Perceptual time information storage D4 Difficulty information storage D5 Cognitive ability memory