Reverse techniques as a means of increasing the validity of the cardio-oculometric diagnostics

Elena V. Brodovskaya, Anna Yu. Dombrovskaya, Vladimir A. Zernov, Elena V. Lobanova, Elvira V. Likhacheva, Lyubov’ P. Nikolaeva, Aleksandr S. Ognev, Mikhail Yu. Rudenko. Reverse techniques as a means of increasing the validity of the cardio-oculometric diagnostics. Cardiometry; Issue 18; May 2021; p.33-37; DOI: 10.18137/ cardiometry.2021.18.3337; Available from: http://www.cardiometry. net/issues/no18-may-2021/cardio-oculometric-diagnostics

Regular supply of reliable information about the attitude of citizens to certain socio-political and economic processes and events is the most important prerequisite for making informed decisions by any modern state and public institutions. Therefore, various surveys used for this purpose have become common practice. And the routine procedure carried out according to the rules of conducting such surveys becomes in itself a source of reducing the reliability of the information received. Due to repeated participation of respondents in surveys, which are conducted in the form of conventional questionnaires, instead of difficult understanding and expressing their true opinion, it leads for a surveyed person to nothing more than to reproduce certain social stereotypes. As a result, expensive and time-extensive surveys increasingly report common stereotypical responses, which differ dramatically from authentic information.

The problem of providing regular, timely, supply of such reliable information is aggravated by very consuming time required for the survey procedures themselves, the complexity of processing primary data and difficulties in choosing a user-friendly form of presentation of the obtained data. To all these difficulties added should be the growing fatigue of everybody involved due to the suddenly appearing annoying interviewers, due to the need, in case of consent to participate in the survey, to spend a lot of time searching for answers to boring questions, as well as due to the struggle with yourself when trying to give strangers honest answers to their sometimes rather sensitive questions.

As numerous recent studies [1-10] show, various variants of cardio-oculometric detection can be successfully used to overcome these difficulties. Serious reasons for this are provided by information about the successful use of eyetrackers in combination with computer-aided cardiographs in engineering-related and social psychology [7], in the study of various human ego states [10], in the diagnostics of personologi-cal characteristics of an individual [1, 2], in the assessment of human responds to stimuli that differ in their modality [3], in the study of various sources of stress [4], in identifying the degree of reliability and validity of information provided by respondents [5-10].

As exemplified above, the efficacy of obtaining primary data was achieved by using specially prepared visual stimuli. The presentation of the latter to the respondent took no longer than 3-5 minutes. At the same time, obtaining primary data did not require any special effort by the respondent. It was enough for him/her just to view a series of images, which appeared on the computer screen for 7-10 seconds. The efficacy and convenience of presenting the final results were provided by automatic processing of the recorded gaze parameters and convenient visualization of their integrated characteristics. The respondent's interest to the research and his/her willingness to provide authentic information were supported by the purposeful use of the phenomena of neurovisual programming and cognitive induction.

Our studies were mainly personological in character, and they were not directly aimed at assessing the viability and applicability of such methods in terms of studying public opinion on socio-political issues, and in this case, due to the above reasons, some additional indicators of the respondents’ honesty are needed, when working with video content. According to our hypothesis, such an indicator can be a comparison of the respondents ' gaze parameters when they work with the same set of visual stimuli in the following two modes: it is mode No. 1 ("authentic gaze") that implies direct contemplation of visual stimuli, when the respondent looks at where he wants within the screen, and it is mode No. 2 ("reverse gaze") when the respondent is offered to choose on the screen anything that, in his/her opinion, is diametrically opposite to his/her original (natural, authentic, true) choice.

Materials and methods

To test our hypothesis, the visual stimuli as described below were presented in mode 1 and mode 2 to a group, which included an equal number of the males and the females. In total, the group covered 48 respondents with an average age of 26 years. Along with these above images, the representatives of the group were presented with additional control visual stimuli. The following visual compositions, which were tested previously in the work in modes No. 1 and 2 with other groups of respondents (in total there were more than 800 people), were used as the stimuli:

• -    stimulus No.1 is a red line placed on a white background with inscription “no way out of line!”;

• -    stimulus No.2 is phrase "where are you?" above the image of three runners at their finish line, the first of which has already reached the finish line, the second is one step away from the leader, and the third runs two steps away from the leader and closes the group of competitors;

• -    stimulus No.3 represents phrase "where are you?" above the image of two contour figures facing the viewer, one of which is an adult without any pronounced signs of belonging to any gender, wearing casual home dress, and the second is a child vigorously beating a drum;

• -    stimulus No.4 offers a contour image of a cow located in the center of the stimulus with word “lion" written on its body, as well as contour images of a lion (the upper right corner of the stimulus), a tiger (the lower right corner), a cow (the lower left corner) and a hippo (the upper left corner);

• -    stimulus No.5 exhibits the colored squares of the Lüscher color personality test arranged in two rows by four above and below the phrase "good mood" (the central segment of this visual stimulus).

To conduct a quantitative analysis of the obtained data using the AOI procedure (where AOI is a standard abbreviation for describing the working procedures of eyetrackers, referred to the word combination "Area of Interest", which denotes a parametric description of the gaze when a test subject is viewing separated areas of the stimulus image, i.e., calculation of the absolute and specific time of fixing the gaze on the elements of interest to the researcher, a count of the gaze returns to the various components of the image, etc.) provided by the GP-3 eyetracker software, we, as in all previous studies, used the following segmentation of the stimuli listed above: - segment No.1: the entire part of stimulus No.1 is above the red line;

• -    segment No. 2: the red line depicted in stimulus No.1; - segment No.3: the entire part of stimulus No.1 below the red line;

• -    segment No.4: the leading runner in the stimulus No.2 image;

• -    segment No.5: the lagging runners in the stimulus No.2 image;

• -    segment No.6: the contour image of an adult in the stimulus No.3 image;

• -    segment No.7: the contour image of a child beating a drum in the stimulus No.3 image;

• -    segment No.8: the contour image of a lion (the upper right corner of stimulus No.4);

• -    segment No.9: the contour image of a cow (the lower left corner of stimulus No.4);

• -    segment No.10: the green square in visual stimulus No.5;

• -    segment No.11: the blue square in visual stimulus No.5; - segment No.12: the yellow square in visual stimulus No.5; - segment No.13: the red square in visual stimulus No.5;

• -    segment No.14: the violet square in visual stimulus No.5; - segment No.15: the grey square in visual stimulus No.5; - segment No.16: the black square in visual stimulus No.5; - segment No.17: the brown square in visual stimulus No.5; - segment No.18: the 120 point size inscription "good mood" in visual stimulus No.5.

The following visual stimuli were also segmented as shown in Figure 1 herein:

• -    segments No.19 and 20 showing the rectangular standard-type national flags of Russia and Ukraine;

• -    segments No.21 and 22 containing words “Russia” and “Ukraine”;

• -    segments No.23 and 24 depicting the flying national flags of Russia and Ukraine;

• -    segments No.25 and 26 displaying the national state emblems of Russia and Ukraine;

• -    segments No.27 and 28 showing words “Moscow” and “Kiev”;

• -    segments No.29 and 30 depicting the national flags of Russia and Ukraine with the their national emblems placed thereon;

• -    segments No.31 and 32 displaying the national flags of Russia and Ukraine with their national emblems and the names of the countries in their national languages shown thereon;

• -    segments No.33 and 34 exhibiting images of the national passports of Ukraine and Russia.

During the exposure of these stimuli on the GP-3 eyetracker screen, the examinees’ cardiograms were recorded in parallel using computer-assisted hemodynamic analyzers Cardiocode. Then, with some specific algorithms in the Cardiocode software, the Baevsky stress index (SI) values were calculated for each examinee.

After the test was completed, a post-test conversation was conducted with each respondent. At that time, records of the respondent's eye movement, his/ her condition, and possible interpretations of the obtained oculometric data were demonstrated and discussed. After completing the testing work with all the examinees, the general processing of the obtained statistics data covering the entire sampling was car- ried out using professional standard software package STADIA 8.0.

Results and Discussion

Based on the results of the completed individual oculographic studies, we determined the average indicators for the collected sampling data as a whole. The results of our work are presented in Table 1 herein.

Table 1 shows that during the transition from mode 1 to mode 2, significant changes in the duration of the fixation time (more than 1.5-2 times) occurred in 31 of 34 segments highlighted and described in detail above. As can be seen from the Table, all changes in the parameters of the gaze, without exception, when passing from one mode to another, are mirror-like, statistically significant and demonstrate the same logical pattern. At the same time, it should be noted that the gaze parameters for segments 1-18 in the specified group of 48 examinees and in the generalized group of respondents (in total, there were more than 800 individuals) were statistically indistinguishable.

When analyzing the data given in Table 1, attention should be drawn to the particularly strong differences in the parameters of the gaze between mode 1 and mode 2, which was fixed on the images of the depicted national state flags. No less significant differences between modes 1 and 2 were obtained in assessing the Baevsky index values. As to mode 1, the arithmetic mean value of the SI parameter reached 211 arbitrary units, while in mode 2 it was recorded to be 327 arbitrary units. It should be noted that the similar patterns were previously reported by us when comparing the SI values in the mode, when according to the preliminary instruction the respondents told the truth, against the mode, when they deliberately told a lie. Discussion of the obtained results with each respondent revealed that when working in mode 2, the respondents experienced noticeable physical and emotional discomfort that was not the case in mode 1. They also noted that the experience of working in the reverse mode significantly facilitated the implementation and understanding of their authentic choice.

Conclusions

The obtained results have confirmed the validity of the second hypothesis of our study that the use of the reverse modes of work by the examinees with visual stimuli presented on the eyetracker screen allows us effectively assessing the degree of honesty in

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Table 1

Average indicators of gaze fixation on separate fragments of test visual stimuli

Segment No	Specific time of fixing the gaze (%)		Segment No	Specific time of fixing the gaze (%)
	Mode 1	Mode 2		Mode 1	Mode 2
1	54	38	18	10	14
2	14	8	19	35	11
3	17	34	20	18	34
4	53	26	21	18	8
5	22	53	22	6	17
6	35	26	23	5	39
7	38	43	24	9	27
8	37	18	25	26	9
9	12	21	26	4	32
10	17	4	27	27	7
11	11	3	28	28	17
12	25	3	29	27	9
13	10	3	30	5	38
14	7	36	31	8	33
15	1	16	32	35	11
16	1	31	33	5	17
17	2	20	34	23	9

work both for each individual respondent and the entire group of the respondents. It has turned out that the combination of "the authentic view" and "the reverse view" modes significantly facilitates all tests for the respondents themselves, simplifies the procedure of the self-determination with their personal choice and makes their participation in research an interesting and exciting event. We have obtained additional evidence that the comparison of the gaze parameters recorded in these modes can serve as supplementary indicators of the degree of subjective significance of various visual stimuli elements for the respondents. Thus, it has been found that if the image includes both words "Russia" and "Ukraine" and the corresponding national flags of these countries, then in order to identify the preferences (where I want to live, who owns the Crimea, which is closer to me) the respondents usually twice longer fix their attention on the flag of the state appropriate for them.

The use of the reverse modes, the person-focused visual stimuli, active participation of the respondents in the discussion to interpret all oculometric and oculographic data obtained therewith increases the motivation of the interviewees to validate various types of information content. The personal context in the described study was effectively identified due to the fact that the oculometric and cardiometric analysis gave good results in determining the characteristic personal traits and the previous experience of the interviewees, which gave a sense to the content discussed.

The above research work has been completed within the framework of the RFBR Grant "Ukrainian information flows in the Crimean segment of social media: risks and technologies to overcome the negative effects of anti-Russian rhetoric in the online environment (No. 18-011-00937 for 2018-2020).

Statement on ethical issues

Research involving people and/or animals is in full compliance with current national and international ethical standards.

Conflict of interest

None declared.

Author contributions

The authors read the ICMJE criteria for authorship and approved the final manuscript.