Comparative analysis of spatial EEG organization on models of non-verbal divergent and convergent thinking

Features of neurophysiological organization of two main thinking types playing different roles in creative processes, i.e., divergent and convergent were studied with participation of 30 right-handed male subjects at the age from 30 to 50 years. Two tests were presented: (1) creation of many visual images on the basis of two simple geometrical figures (the model of divergent thinking) and (2) classification of a figure element with one of the offered standard samples (convergent thinking). The number of created images or correctly classified elements for five minutes served a criterion of performance productivity. It was found that performance of the divergent test with high productivity (as compared to low productivity) was characterized by a greater increase in non-linear interactions between the cortical potentials, especially in the axis right frontal--left occipital areas. At the same time, under conditions of high productivity, the number of active narrow-frequency spectral-coherent EEG bands increased. The data confirm the notion of neurophysiological organization of creative processes, according to which creative processes require the intensification of retrieval operations (both conscious and unconscious), based on extensive interhemispheric interaction and involvement of a system of EEG coherent structures oscillating with different frequencies.     

Features of spatial organization of EEG and psychophysiological characteristics of the person with the divergent and convergent types of thinking

The psychophysiological indicators of spatial synchronization of biopotential at different types of mental processes in humans: non verbal-divergent, nonverbal-convergent, verbal-divergent and verbal-convergent were analyzed. The unequal relationship between the productivity of the implementation of tests on these types of thinking was revealed. The closest significant correlation exists between the productivity of the verbal-divergent and verbal-convergent thinking, and the lowest--between the productivity of nonverbally-divergent and nonverbally-convergent thinking. The differences in the topographical maps of the spatial synchronization of biopotential at different types of thinking was marked. They are most pronounced in the implementation of two non-verbal tasks, minimal--in two verbal tasks. Differences between different types of thinking are also manifested in the degree of coherence gain biopotential of the performance tests in comparison with the background (open eyes). Some physiological properties of the person that contribute to the divergent (creative) tests have a negative impact on the implementation of converged (tedious) tests. The findings are discussed in terms of differences in the level of general activation and participation of different ways of processing information (simultaneous and successiveness).     

The EEG spatial pattern and psychophysiological characteristics of divergent and convergent thinking in humans

The psychophysiological parameters of the spatial synchronization of bioelectric potentials during the nonverbal divergent, nonverbal convergent, verbal divergent and verbal convergent thinking have been analyzed. The relationships between the performances of tests for these thinking styles were different. The strongest significant correlation has been found between the productivities of the verbal divergent and verbal convergent thinking styles; the weakest correlation, between those of the nonverbal divergent and nonverbal convergent thinking styles. The thinking styles differ from one another in the topography of spatial synchronization of bioelectric potentials. They are the most pronounced during the two nonverbal tasks and the least pronounced during the two verbal tasks. The thinking styles also differ from one another in the degree of the enhancement of the coherence between bioelectric potentials during tasks compared to the baseline (with the eyes open). Some human psychophysiological characteristics facilitating the performance of divergent (creative) tasks have a negative effect on the performance of convergent (noncreative) tasks. The data are discussed in terms of the differences in the level of general activation and involvement of different types of information processing (simultaneous and successive).     

Parameters of the spatial of organization of EEG in persons with various individual characteristics

The relationships between some characteristics of EEG topographic maps and personality traits (extraversion-introversion, sensation-intuition, thinking-feeling, judging-impulsiveness) by the Keirsey's Type Inventory were studied in 46 17-20-year-old men). The most considerable distinctions in the spatial organization of the EEG were observed between the functions sensation and intuition. The high-sensation responders were characterized by higher EEG power in the theta 1, 2 and alpha 1-bands in all derivations and higher coherence (especially in the theta 1, 2 bands most expressed in the frontoparietal areas) as compared with the high-intuition responders. The expression of extraversion was positively correlated with coherence values in the theta 1, 2 and negatively correlated with coherence in the alpha 1, 2 bands. Characteristic EEG patterns for other types of personality traits were also described. The results suggest that some characteristics of brain maps reflect the individual psychological features determined on the basis of Jung's typology.     

Influence of informational oversaturation on the quality of creative activity and spatial organization of EEG

The features of the spatial organization of bioelectric potentials in the cases of successful and unsuccessful creative imagination (refusal or poor quality of the product) under conditions of informational oversaturation. Two groups of subjects were compared: professionals (23 healthy students of the Department of Graphic Arts) and non-professionals (34 persons whose specialties were not linked with systematic visual imagination). During the experiments, the subjects were asked to mentally create a visual image based on two simple graphic elements, a right angle and a diagonal; after recording the EEG, they had to draw the image on paper and give it a title. The total number of elements exceeded 7 ± 2; hence, information processing at the conscious level was impossible, which caused the necessity of involving the mechanisms of unconscious information processing. The quality of the created product was evaluated with regard to the degree of success of performing the task and the features of spatial EEG organization. The EEG was recorded from 24 scalp sites of a subject using a SIT-EEG portable telemetric device. In the case of the successful performance of the task by professionals, the parameters of spatial organization of bioelectric potentials, i.e., spatial synchronization (linear processes) and spatial disorder (non-linear process) were strengthened compared to the base-line level in the frontal temporal areas of the right hemisphere and parietal occipital areas of the left hemisphere. Conversely, in the nonprofessionals, these parameters increased in the frontal temporal areas of the left hemisphere and parietal occipital areas of the right hemisphere. In the case a task was not successfully performed by the professionals, the spatial disorder of bioelectric potentials increased in all the cortical areas; in the nonprofessionals, only weak changes were observed. In all situations, the groups differed also in the parameters of coherence (Coh), spectral power (Sp) of bioelectric potentials, and informational energy, which reflects the level of expenditure of the brain’s energy for information processing. The evidence obtained is interpreted in terms of electroencephalographic correlates of successful task performance by professionals and nonprofessionals, i.e., their creative imagination under the conditions of informational over-saturation.     

Influence of information over saturation on quality of creative activity and EEG spatial organization

In work the features of the biopotentials spatial organization are surveyed at successful and unsuccessful (abandoning or bad quality of a product) implementation of creative imagination in conditions of information over saturation. Two groups of the examinees have taken part in experiments: "professionals" (23 able-bodied examinees--students of faculty of an art graphics) and "nonprofessionals" (34 men, which specialty were not linked to systematic visual imagination). During experiment the examinees should mentally frame a visual object on the basis of two simple graphics units--right angle and diagonal, and after EEG registration to draw it on a paper and to give a title. The total number of units exceeded 7 +/- 2, i.e. the possibility of information processing at a realized level was unreal that reduced in necessity of connection of mechanisms of not realized information processes. Estimated quality of a framed product from the point of view successful and unsuccessful of implementation of the job and conforming to each of these variants of a feature of the EEG spatial organization, which shunted with the help of portable telemeter installation "SIT-EEG" from 24 items convexital surface of a head. Is shown, that at successful performance of the job in comparison with unsuccessful for "professionals" biopotentials spatial organization parameters--spatial synchronization (linear processes) and spatial disorder (the nonlinear processes) strengthen (in relation to a background) in frontal-temporal areas of the right hemisphere and parietal-occipital left ones. For "nonprofessionals" the value of these parameters was enlarged in an inverse direction: in frontal-temporal areas of the left hemisphere and in the right parietal-occipital. At unsuccessful performance of the jobs for "professionals" the body height ofbiopotentials spatial disorder almost in all cortical zones was marked, for "nonprofessionals" of change were weak. The between group differences in all situations for parameters ofbiopotentials coherence and spectral power are found also for "Informational - power" parameter mirroring a level of power expenditures of a brain on implementation of information processes. The obtained data are treated from the point of view ofelectroencephalographic correlates of successful and unsuccessful implementation of the job by "professionals" and "nonprofessionals" for creative imagination in conditions of information over saturation.     

Reflection of individual typological features in the structure of spatial interaction of EEG waves of various frequency ranges

The role of EEG β-, α-, and θ-activity in the formation of the structure of the spatial interaction of cortical formations and interhemispheric balance (IB), evaluated on the basis of the matrix of conditional probabilities, were studied in healthy test subjects occupied with oil refining. Preliminarity, the groups of test subjects with high (I), average (II), and low (III) adaptivity were distinguished. Individuals with a positive IB prevailed in groups I and II and among the test subjects with the length of service less than 20 years, and those with negative IB were in the majority in group III and among the test subjects with the length of service over 20 years. The structure of spatial interaction of EEG waves of test subjects with high and average adaptivity, as well as those with positive IB and length of service below 20 years, was determined mostly by α-activity. The spatial pattern of EEG of test subjects with low adaptivity, as well as those with negative IB and length of service above 20 years, was determined by the interaction of bioelectrical activity mainly in the α- and β-ranges.     

EEG spatial organization and activation of creative processes

Characteristic features of the spatino-temporal EEG organization of 24 right-handed children (aged from 8 to 13 years) were studied after stimulation of creative activity by the method of self-regulation of the brain functional state (Russian Inventor's Certificate no. 2157707, 01.06.1999). The multiparametric analysis of baseline recordings derived from 24 cortical points made it possible to find the most probable pattern of changes in the spatial synchronization of biopotentials, including increase in activity in the right anterior and left posterior cortical regions. These changes were accompanied by a rise in the information-energy parameter (the ratio between coherence and spectral power of potentials). This phenomenon may testify to a transition to the "economic" condition of information processing. Differences in EEG frequency characteristics corresponding to different levels of imagination and creative intuition were revealed.     

The influence of visual imagery experience on EEG spatial organization

The comparison of EEG spatial organization between groups of 23 students of graphic arts department ("professional" subjects) and 39 subjects of another specialization ("non-professional" subjects) was made in order to find EEG correlates of visual imagery experience. Changes in the spatial organization of biopotentials (spatial synchronization and spatial disorder, spectral power and coherence) were analyzed while subjects mentally composed visual images from two simple elements, right angle and oblique line. The total number of elements presented for the image composition increased with each subsequent task (in total, four tasks were presented) from the number adequate to simultaneous perception and conscious processing (less than 7 +/- 2) to a much higher number. Intergroup differences, especially, in the degree of the spatial disorder (non-linear processes), were most evident under conditions when the subjects operated with a greater number of elements (tasks 3 and 4). This parameter increased more rapidly in "professionals" than in "non-professionals". These changes were most pronounced in the right anterior cortex. In "non-professional" subjects, spatial synchronization (linear processes) increased in the right posterior area. In "professional" subjects, coherence and spectral power increased in a greater number of narrow EEG frequency subbands than in "non-professional" subjects. The findings suggest that the imagery performance in subjects with visual imagery experience involves complicated neurodynamic processes such as non-linear dynamics and numerous EEG spatial resonance systems.     

EEG spatial organization during intense hyperventilation (cyclic breathing): II. EEG correlates of psychovisceral phenomena

EEG correlates of two main effects of long-term hyperventilation (cyclic breathing similar to rebirthing), namely, psychotic manifestations and sensations in internal organs, are considered. Standard EEGs of 44 subjects were recorded and subsequently treated by multiparametric methods. It was shown that, in the case of psychotic phenomena (hallucinations, visual and auditory images, different scenes, virtual travels, out-of-body experiences, etc.), the changes in the spatial organization of bioelectric potentials as compared with the baseline have different patterns than in the case of sensations in internal organs. The changes are observed in the frontal regions of the cortex: a decrease in spatial synchronization (linear processes) during an increase in spatial disarray (nonlinear processes) of bioelectric potentials and the intensifying of high-frequency β activity. If sensations in internal organs appear, a decrease in the above parameters was observed in the right hemisphere and in posterior cortical areas. The data are discussed from the viewpoint of qualitative specificity of changes in functional states during an altered state of consciousness with manifestations of different psychovisceral phenomena.     

Comparative analysis of EEG spatial organization in the rats with different level of genetically determinated anxiety under ethanol

The pecularities of EEG changes in the rats with geneticaly different level of anxiety was studed after ethanol injection. The biopotentials spatial synchronization and entropy in the "high anxious" rats (strain MR) did not increase under low dose; on the contrary the above changes were characteristic for the rats without anxiety signs (strain MNRA). After injection of middle and high ethanol doses the "high anxious" rats as compared with "low anxious" ones had the "simplification" of reaction type--the increase of narrow frequency coherence (i.e. linear biopotentials relationship) and spectral power of theta-activity (5.75-7.25 Hz), which was combined with the decrease of nonlinear biopotential characteristics. This fact is interpreted as the predominance of subcortical mechanisms of the brain functional state regulation over cortical ones. The significant decrease of high frequency EEG components in "high anxious" rats takes place under more high ethanol doses, presumably reflecting the increase of the anxiolytic level of ethanol effect.     

EEG correlates for efficiency of the nonverbal creative performance (drawing)

This work was aimed at a search for EEG corellates of efficiency of nonverbal creative performance. Standardized Torrens technique which makes it possible to quantitatively assess creativity was used. The EEG records were performed before and during test performance, EEG parameters were compared to Torrens scores on three scales: flexibility, originality and efficiency. Absolute values of spatial synchronization, coherence and spectral power both in the baseline and during the performance were calculated. Changes in these parameters were traced during the transition from the state of quiet wakefulness to creative performance. The narrow-band analysis of coherence and spectral power allowed the number and orientation of processes associated with creativity scales to be assessed. The absence of substantial EEG changes during the test performance is indicative of the steady, nondynamical functional state of the brain.     

Changes in the EEG power during tests for nonverbal (figurative) creativity

The EEG was recorded in 19 standard derivations according to the international 10–20 system in 30 subjects during a test for figurative creativity. To involve subjects in the creative process, they were presented with the following creative tasks: (Cr1) thinking up and drawing an original picture; (Cr2) drawing a face, a house, and a clown in an original manner; (C1) drawing a picture from memory; and (C2) drawing geometric figures without any system. All the tasks had to be performed using a given set of geometric figures (a circle, semicircle, triangle, and rectangle). Statistical analysis of the EEG spectral power for the frequency bands α₁, α₂, β₁, β₂, and γ showed that the creative task performance was characterized by an increase in the EEG power in the β₂ and γ bands and single differently directed power changes in the α₁, α₂, and β₁ bands. The findings were compared to previous results of EEG studies on creative activity.