The effects of the experience of forming visual images on the spatial organization of the EEG

Abstract

The spatial organization of biopotentials in the cerebral cortex of 23 subjects who were students at the Faculty of Graphic Arts ("professionals") as well as 39 subjects lacking systematic experience of visual images ("non-professionals") was compared with the aim of identifying EEG correlates of the experience of visual images (image formation) in humans. Changes in measures of the spatial organization of biopotentials (spatial synchronization, spatial disordering, coherence, and spectral power) were analyzed as subjects mentally composed visual images consisting of two simple graphic elements - right angles and oblique lines. The total number of image elements increased in each of four sequential tasks, from a number which could be analyzed at the conscious level (4-7 elements) to a number exceeding analysis at the conscious level (8-16). Intergroup differences, particularly increases in the spatial disordering of biopotentials (non-linear processes), were detected when large numbers of elements were used (tasks 3 and 4). This measure increased more markedly in professionals than in non-professionals. Changes were significant in the anterior areas of the right hemisphere. Spatial synchronization of biopotentials (linear processes) increased in non-professionals in the posterior areas of the right hemisphere. Coherence and spectral power increased in professionals in a larger number of narrow-band EEG frequency subranges than in non-professionals. These data show that experience of visual imagery results in a more complex neurodynamic process during the activity, with non-linear dynamics and a multitude of EEG resonance systems at different frequencies.

Can the Psycho-Emotional State be Optimized by Regular Use of Positive Imagery?, Psychological and Electroencephalographic Study of Self-Guided Training

“…Here we hypothesized, that if efficiently, then self-guided positive emotion-focused imagery training will demonstrate a beneficial effect on the emotional state of the trainees called out by psychological testing (first hypothesis), and will be linked with EEG changes, explainable by the training (second hypothesis), namely: (a) from a topographical point of view, it could be expected changes in the structures/regions participating in the imagery or/and emotional processing; (b) anticipated increase in EEG connectivity [in accordance with previously reported data on the practice of visual imagery (Sviderskaya et al, 2006)]; (c) since the imagery training by itself is a creative work, some of the changes in EEG are supposed to occur in theta range, which is one of the most frequently reported as involved in the creative process (Petsche, 1996). …”

“…As these regions that are involved in the processing of images (Mellet et al, 1996), enhancing the coherence between them may indicate that the training caused an improvement of coordination of relevant networks located in temporal gyruses. Increased EEG coherence has been reported in connection with the visual imagery of simple graphical elements (topographic distribution and bands of observed changes have been different, depending on previous experience) (Sviderskaya et al, 2006), so it can be assumed that increased inter-hemispheric lagged coherence between inferior temporal gyruses is associated with the image forming process in general, but do not reflect the content of the images. Further, it can be supposed that the increase in the functional connectivity between the PCC and the right inferior temporal gyrus is associated with recurrent self-image processing in the course of the training, as among the various functions, PCC also plays a role in the self-referential process (Garrison et al, 2015).…”

How do Creativity Levels and Stimulus Types Matter? A Preliminary Investigation of Designer Visual Association

“…In addition, the power differences in the left frontotemporal cortex appeared primarily in bands with frequencies lower than 20 Hz. This finding is consistent with prior research [25,45,49] because it indicates that visual association in the LC designers resulting from realist art stimulation might be involved in episodic encoding and retrieval, particularly when theta-delta coherence is activated.…”

“…For example, strong delta coherence has been observed in the occipitotemporal regions of HC individuals [24,25]. A similar pattern has been demonstrated in the theta band of HC participants [25,26].…”

“…For example, strong delta coherence has been observed in the occipitotemporal regions of HC individuals [24,25]. A similar pattern has been demonstrated in the theta band of HC participants [25,26]. Low alpha coherence has been found to be activated in the bilateral frontal and middle parietal regions of creative individuals [26,27].…”