RU2348344C1 - Test procedure for intensity of interhemispheric interaction (iihi) of human cerebrum - Google Patents

Abstract

FIELD: medicine; psychophysiology.

SUBSTANCE: there is presented set of test figures formed within visual field of examined patient from binocular overlapping of images generated by Julesch's random-point stereograms method. Herewith flat turn angle is registered for one pair image whereat the test figure is not perceived as solid. Registered threshold angle is used as quantitative index of IIHI. Herewith there is a test object presented within visual field of examined patient and containing two image sequences; each image of the second sequence in each subsequent stereopair is turned in its own plane, around its own centre by the angle relative to image position in the first sequence. The turn angle increases as far as serial number of the image increases, and threshold angle is determined by serial number of last image perceived by the examined patient as solid.

EFFECT: extended range of facilities to test IIHI of human cerebrum.

6 cl, 1 tbl, 4 ex

Description

The invention relates to methods for measuring the psychophysiological characteristics of a person and assessing the functional state of his brain, namely, to methods for determining the intensity of interhemispheric interaction (IMPI) of the brain, and can be used in engineering psychology, pedagogy, acmeology and medicine in order to optimize labor, educational and therapeutic processes, professional selection and career guidance.

Known electroencephalographic (EEG) method for determining the current value of IMPV. The method includes continuously recording for some time (30 s or more) the values of electrical activation in two leads - from the right and left hemispheres of the brain - and determining the coherence of the vibrational activity of the recorded potentials. The degree of coherence of potentials recorded over a certain period of time is used as a quantitative indicator of the current value of IMPI (Sokolov E.M., Zherebtsova V.A., Sapogova E.E., Khadartsev A.A. Investigation of the mechanisms of organization and correction of higher mental functions in ontogenesis / / Valeology. - Rostov-on-Don: Publishing House of the RSU, 2002, No. 3. P.78-86).

According to modern concepts, the coherence function reflects the degree of integration, or attunement, of various areas of the brain to the implementation of the psychophysiological process. Higher coherency between the two signals means a higher degree of functional interaction and higher integration between these brain regions. An increase in the coherence of signals in a pair of leads indicates an increase in the intensity of functional interaction between the hemispheres of the brain (Pasynkova NR EEG correlates of the meditative state // http://tm.org.ua/brain_functioning.html).

The disadvantages of the EEG method are the ambiguity of the obtained quantitative data and the complexity of their interpretation, as well as the large (at least 30 s) time spent on the procedure for measuring quantitative data. This circumstance does not allow us to interpret the quantitative value determined by the EEG method as a fairly accurate current value of IMPV, suitable for analyzing the influence of fast-flowing external influences. In addition, the method is used in laboratory conditions and does not allow measurements in the conditions of real life.

A known method for quantifying the functional state of the human cerebral cortex by influencing the subject’s visual apparatus, namely by measuring the critical frequency of fusion of light flickers of red and green colors, perceived binocularly, while at each step in the interval of 5-10 s, the light pulse repetition rate is gradually changed to subjective fusion of flickers for each color (Pat. RU 2141244, АВВ 3/06, publ. 1999.11.20). The disadvantage of this method is its duration in time and the inability to obtain a quantitative characteristic of the cerebral cortex, which can be interpreted as the current value of IMPV, suitable for the analysis of fast processes in the brain.

Closest to the claimed method according to the purpose and number of equivalent features is a method for determining the current value of IMVI, in which the threshold angle of preservation of strereopsis or stereoscopic perception is used as a quantitative indicator of the current value of IMVI (Ostrovsky V.A. Intensification of interhemispheric interaction in the human brain as acmeotic educational resource // Innovative technologies in education and science. Proceedings of the International Scientific and Methodological Conference October 17-19, 2006 - Zyryanovsk: Publishing House of the Zyryanovsky Center EKSTU, 2006. Part 2. - S.262-267. Prototype). Information on the theoretical validity of the known method is published in specialized literature (Ostrovsky V.A. Stereopsis destruction limits as markers of lateral interaction intensity and thinking productivity // Izvestiya TRTU. Thematic issue "Psychology and Pedagogy". Taganrog: Publishing House TRTU, 2005. No. 5 (49). - S.192-196).

The known method includes the following procedures: by means of a stereoscope, the subject is presented with binocular for visual perception an image of a geometric figure made according to the method of random dot stereogram of Yulesh, for example, an image of a square that is subjectively perceived as three-dimensional.

Obtaining a test pair of images by the method of randomly-point stereograms of Yulesh is as follows: a sheet of paper is uniformly filled with random points, for example, by spraying drops of paint from a spray gun. Then, an exact copy of this image is created and a modification is made in a certain section of one of the images: a section is cut out, for example, in the form of a square and it is shifted horizontally, and the resulting empty section is filled with random dots by additional spraying of paint droplets. Being binocularly aligned in the field of view, two images give the effect of a three-dimensional image of a modified area, which is used as a test figure (1. Julesz B. Binocular depth perception without familiarity cues // Science, 1964, vol. 145, N 3630, p. 356-362. 2. I. Rock. Introduction to visual perception. M: Pedagogy, 1980. Volume 1, P.127).

After the subject has the subjective effect of volume perception of the test figure, one of the stereocouple monocular images is rotated in its own plane by a certain angle and presented to the subject for visual perception. It uses the property of the brain that one image is analyzed by one hemisphere, left or right, and the stereo effect occurs due to interhemispheric interaction. The capabilities of integral analysis for each brain are individual. With an increase in the angle of rotation of one of the images, the effort spent on building a three-dimensional (stereoscopic) figure also increases. Flat rotation is carried out until the rotation angle reaches a threshold value at which the subject's visual perception and, accordingly, the perception of the test figure disappear. The subjective subjectively states the disappearance of the image of the test figure. The limit value of the angle of said rotation or, the same thing, the threshold angle of preservation of strereopsis is used as a quantitative indicator of the current value of IMPV.

A known method for determining the current value of IMPV is selected for the prototype.

The essential features of the prototype method are the presentation to the subject of a series of test figures formed by binocular combining in the field of view of the subject a pair of images obtained by random-point stereograms of Yulesh and fixing the angle of flat rotation of one of the paired images at which the test figure ceases to be perceived and merges with the background .

The disadvantage of this method is that it takes a lot of time (at least 30 s) required to perform the procedure of mechanical rotation of the frame, which is a frame with a monocular image fixed in it, which does not allow us to interpret the value measured by its implementation as a fairly accurate current value of IMPV and, therefore, it does not allow to diagnose the latter in dynamics, to analyze the influence of external influences on mental and physiological processes, for example, on the process of solving subjects false intellectual tasks.

The technical task of the invention is to obtain the current value of IMPV, which can be interpreted as its instantaneous or close to instantaneous value, which will allow using this quantitative value in the analysis of fast processes. This can be achieved by reducing the time spent on the procedure for a single measurement of the threshold angle.

The technical problem is solved in that a series of test figures is grouped into a single test object, for which a first sequence of at least three randomly-point images is placed on a plane, and a second sequence formed from the same images, each of which subjected to rotation by a certain proper angle relative to the position in the first sequence, and present to the subject both planes at the same time, combining them in the subject's field of vision.

When implementing the proposed method due to the fact that the subject simultaneously sees in the field of view both stereoscopic figures and those binocularly combined images in which due to the large angle of rotation the stereo effect does not occur, the duration of the procedure for measuring the current value of IMVI is reduced to 1-2 seconds in difference from 20-30 seconds by the prototype method. For example, if the figures are numbered, the subject almost instantly calls the figure number without the stereo effect, and the subject immediately determines the threshold angle of stereoscopic perception from the table. This increases the efficiency of determining the target parameter, which, in turn, makes it possible to identify the influence of dynamic (rapidly changing in time) effects on the human brain.

The current value of IMPV can serve as a characteristic of the state of the subject. Averaged over multiple measurements, the value of IMPV can serve as an individual characteristic of the subject by analogy with an individual indicator of intellectual abilities, which opens up possibilities for its correction and will be widely used in teaching and career guidance, especially for intellectual professions. The quantitative value of IMPV can be expressed in a dimensionless form. According to our fairly representative samples, the average value of the threshold angle of preservation of stereopsis (PUSS) is 28.4 °. The ratio of the measured angle characterizing the individual IMPI of the subject to this average value gives a value convenient for practice, which can significantly differ from unity.

The method can be implemented as follows.

A stereopair is made of two slides according to the Yulesh method, each of which contains a certain sequence of images. Each subsequent image of the sequence on the right slide of the stereo pair, starting from the second (the order is from left to right, from top to bottom), is rotated in its own plane around its own center by an angle smaller than the threshold and increasing as the serial number of the image increases.

In the concordant portions of the visual fields of the right and left eyes, test subjects are presented with a stereoscope by a stereoscope. The peculiarity of the method is that the test image contains several elements at once, for example, twenty non-repeating explications of a graphic image, in particular a square, each of which is executed as Yulesh random-point stereograms. Images are evenly placed in the field of view on a stereo pair in the form of a rectangular table of size, for example, 5 × 4 (4 rows of 5 images each). The test subject binocularly examines the image through a stereoscope and, in accordance with the instruction with which he is familiarized in advance, names the serial number of the test mark that the last in the series contains a subjectively perceived volumetric test figure. By the named serial number of the element accessible to binocular perception (in other words, the number of the test sign recognized by the subject), the current value of the threshold angle of the stereopsis is judged. The resulting quantitative value is interpreted as the quantitative value of the intensity of the interhemispheric interaction of the subject’s brain, and its instantaneous, current value.

To increase the accuracy of the procedure, the said rotation angle of the image relative to its position in the first sequence is selected as small as possible.

The figures may additionally be located next to each other, for example in the form of a snake. This reduces the time for moving the gaze from the figure to the figure, which reduces the time spent on testing.

In addition, the claimed method is not limited to the presentation of figures in the form of squares or other figures having the correct geometric shape, and the images of the first sequence are not necessarily identical to each other.

The method increases the accuracy and efficiency of obtaining a test parameter, allows you to study the influence of dynamic (rapidly changing in time) effects on the human brain, which corresponds to the task.

Example 1. Combining two sequences, the subject is offered a set of stereoscopic elements. The subject sees in the field of view several numbered images at once, with some of the figures perceived as voluminous, the rest as flat. Only those figures for which the modified image is rotated by an angle smaller than the threshold are perceived voluminously. The smaller the rotation step, the more accurately the threshold angle of stereoscopic perception is determined. However, the choice of a small step leads to the need to mix a large number of images simultaneously in the field of view, which is not always possible. Therefore, several steps can be large (5, 8 and even 10 angular degrees), and the subsequent steps can be small, possibly with a decreasing step, which reduces the methodological error of the method. This feature according to the invention is equivalent to the fact that part of the modified images is removed from the sequence and is not presented to the subject. For example, they make a sequence of 20 modified images with serial numbers 1, 2, 3 ... 20 with a constant rotation step of 1.2 degrees, i.e. the twentieth image is rotated 24 degrees relative to the original, but images with numbers 1, 9, 15, 17, 18, 19, 20 are placed on the test plane. The bulk effect disappears, as a rule, for the 17, 18, 19 or 20th image. Let it be, for definiteness, No. 18. The limiting angle lies between 21.4 ° (17 × 1.2 °) and 21.6 ° (18 × 1.2 °) degrees, and is 21.5 ° ± 0.1 °.

In this example of the implementation of the claimed method, it is not the angle of rotation that is fixed, but the serial number of the figure: the time spent on moving the look from one figure to another is minimal, unlike the prototype method.

Example 2. For the technical implementation of the proposed method, the components of a stereo pair of monocular images do not have to be applied to paper or another plane. In particular, one or another version of the well-known anaglyphic method for displaying stereo images on a screen can be applied. Here is a brief description of it. The demonstration of stereoscopic images by the anaglyphic method is ensured by the following three conditions:

a) the monocular images making up the stereo pair are painted in different monochromatic colors, for example red and green. If the color of the image intended for perception by the left eye is selected in green, then the color of the image intended for perception by the right eye is selected in red, and vice versa.

b) monocular images constituting a stereo pair are superimposed on each other, thus forming a test figure (TF), and demonstrate to the test subject on the same screen through special glasses;

c) glasses of glasses are monochromatic filters with spectral transmission regions identical to the selected monochromatic colors, but with the glass arrangement opposite to the stereo pair of monocular images;

During the test, subjects examine the image displayed on the screen so that the examinee looks at the green image through the red filter with the left eye and the red image through the green filter with the right eye. Subjectively, the subject perceives TF as a set of elements, for some of which there is a stereoscopic effect, for the remaining part - not, i.e. elements are flat. The stereoscopic effect is observed only for those elements for which the angle of rotation mentioned above is less than the maximum.

Example 3. The tests of example 2 were carried out on 20 subjects. A computer version of the anaglyph method for demonstrating stereo images described above has been implemented. The following equipment is used: a computer with software suitable for anaglyphic demonstration of stereo images (Windows XP operating system; StereoPhoto Makers program); color monitor "Samsung SincMaster 900 IFT" 19 inches, resolution 1200 × 1600 pixels; Anaglyph glasses (red and green filters are taken from the Spectrozon photo printing device kit of the Photopribor factory). The image of the test figure (TF) consisted of two monocular components - red and green. The red component was a series of randomly-pointed stereograms of the Yulesh square in red. This set of “non-rotated components” is intended to be perceived by the left eye. The green component of TF is formed by many "rotated components" and is intended for perception by the right eye. Pairs, consisting of concordantly located relative to each other elements of the two mentioned sets, formed as a result a lot of elements of the test figure, or TF-elements. The molecular components of each TF element are made in the form of the same size of circles, which are aligned in the plane of the anaglyphic window. The centers of TF elements are located at the intersection points of several mental horizontal and vertically oriented straight lines. The number of elements in the TF was chosen equal to 35 (5 lines of 7 elements each), which is not significant, and other options are possible. It is also not necessary, but it is advisable to fulfill three conditions. First, all TF elements were placed against a common dark background. The second - TF elements had the same size. Thirdly, any subsequent (having serial number n + 1) element of the set of “rotated components” was an image obtained from the previous image through the right central rotation at the same angle. The instruction with which the subject was acquainted in advance instructed him, wearing anaglyph glasses, to analyze the images of TF elements in the “snake” sequence, which reduces the time of fixing the image with a threshold angle of rotation. The instruction instructed the subject to name the line number and column number of the TF element, in which the image of the Yulesh square was perceived as voluminous. The numbers are entered in a table that matches the figure number and the rotation angle. The subject examined the demonstrated test object on the screen through anaglyph glasses and indicated the number of the image rotated by the threshold angle of stereoscopic perception. The subject’s continuous speech report was synchronously recorded by the experimenter, who quickly determined the value of the largest angle at which the individual’s individual stereopsis was stored at the current time. The described embodiment of the method allows to obtain the instantaneous (or close to instantaneous) current value of IMPV, which makes it possible to use this quantitative value in the analysis of fast processes and to solve a wide range of applied problems.

Example 4. Comparison of the claimed method with the prototype method. In order to illustrate the advantages of the proposed method in terms of efficiency, the applicant performed a comparative study (a coherent sample of subjects, students 18-25 years of age, N = 10). The study consisted in the fact that in two series of 10 measuring samples each, which were separated from each other in time by 1 hour, the subjects measured the current value of the threshold angle of conservation of stereopsis. In the first series, measurements were made according to the prototype method, in the second - the claimed method. In each series, individual measurements were made continuously, following one after another and forming a continuous test in time. Personal values for the duration of each series were recorded in the test report. By averaging over the sample of testees and over the measurement values, one can introduce such an informative indicator as for the compared methods, such as the characteristic time of one measurement. To increase the effectiveness of the claimed method in some cases, the testee's speech was recorded by a computer using a sound recording program and saved in the form of an audio file. The method of automatic recording is advisable in cases where the research task requires the maximum achievable accuracy of recording the value of the threshold angle of conservation of stereopsis. Comparative characteristics of the measurement efficiency are given in table 1. From the data given in the table it can be seen that the efficiency of the claimed method is an order of magnitude superior to the prototype method.

Abbreviations:

IMPV - the intensity of interhemispheric interaction;

EEG - electroencephalography;

TF - test figure;

PUSS - threshold angle of stereopsis safety.

Literature

1. Sokolov E.M., Zherebtsova V.A., Sapogova E.E., Khadartsev A.A. The study of the mechanisms of organization and correction of higher mental functions in ontogenesis // Valeology. - Rostov-on-Don: Publishing house of the RSU, 2002, No. 3. S.78-86.

2. Pat. RU 2141244, A61B 3/06, publ. 1999.11.20.

3. Ostrovsky V.A. Intensification of interhemispheric interaction in the human brain as an acmeotic educational resource // Innovative technologies in education and science. Proceedings of the International Scientific and Methodological Conference October 17-19, 2006 - Zyryanovsk: Publishing House of the Zyryanovsky Center EKSTU, 2006. Part 2. - P.262-267.

4. Ostrovsky V.A. The limits of the destruction of stereopsis as markers of the intensity of lateral interaction and the productivity of thinking // News of TRTU. Thematic issue "Psychology and Pedagogy". Taganrog: Publishing house of TRTU, 2005. No. 5 (49). - S.192-196.

5. Julesz B. Binocular depth perception without familiarity cues // Science, 1964, vol. 145, N 3630, p.356-362.

6. I. Rock. Introduction to visual perception. M. Pedagogy, 1980. Volume 1, P.127.

Table 1 Comparative characteristics of the measurement efficiency of the PUSS according to the claimed method in comparison with the prototype (seconds) Test subject random number one 2 3 four 5 6 7 8 9 10 The time taken to perform 10 measurements by the prototype method 828 331 238 421 178 306 340 393 347 429 The average time of 1 measurement by the prototype method 83 33 24 42 eighteen 31 34 39 35 43 Averaged over all participants in a coherent sample of test subjects, the execution time of 1 measurement by the prototype method 38,2 The time taken to perform 10 measurements according to the claimed method 41 26 22 36 eighteen 26 thirty 35 34 39 The average time of 1 measurement by the claimed method 4.1 2.6 2.2 3.6 1.8 2.6 3 3,5 3.4 3.9 Averaged over all participants in a coherent sample of test subjects, the execution time of 1 measurement by the claimed method 3.07

Claims (6)

1. A method for determining the intensity of interhemispheric interaction (IMPI) of the human brain, including presenting a series of test figures formed by binocular matching in the field of view of the test pair of images obtained by randomly stereograms of Yulesh method, fixing the angle of flat rotation of one of the paired images, in which the test the figure ceases to be perceived as volumetric and the use of the value of the fixed threshold angle as a quantitative indicator of IMPV, characterized in that in the field of view of the test subject present a test object containing two sequences of images; each image of the second sequence in each subsequent stereo pair is rotated in its own plane, around its own center by an angle relative to the position of the image in the first sequence, while the rotation angle increases with increasing serial number of the image, and the threshold angle is determined by the serial number of the last image, which the subject is subjective perceives as surround. 2. The method according to claim 1, characterized in that the angle of rotation of the image relative to its position in the first sequence is selected as small as possible, and the angle of rotation between the previous and subsequent image of the second sequence is constant or decreases monotonously. 3. The method according to claim 1, characterized in that the images of the sequences closest in rotation angle are placed next to each other, for example, in the form of a line, a spiral or a snake. 4. The method according to claim 3, characterized in that the distance between the images of the sequences is chosen as small as possible. 5. The method according to claim 1, characterized in that the images of the first sequence are not necessarily identical to each other. 6. The method according to claim 1, characterized in that the images of the first sequence do not necessarily have the correct geometric shape.