Prestimulus EEG gamma frequencies during formation of a cognitive set to facial expressions.
The power spectra of baseline (prestimulus) EEG recordings from various parts of the cortex in the band 1-60 Hz were studied in adult subjects during the stage of formation of a cognitive set to facial expressions. Individual variability in the power spectra of the baseline EEG, particularly in the gamma range (41-60 Hz) made it impossible to average spectra from different subjects. This is the first study demonstrating that the EEG at 41-60 Hz was more informative during the prestimulus period than recordings at 1-20 Hz and 21-40 Hz. High levels of gamma-frequency power were found to be dominant in the frontal areas of the right hemisphere in groups of subjects with plastic sets; the group of subjects with a rigid set showed dominance of gamma-frequency power in the posterior temporal and occipital areas of the left hemisphere.
Dumenko
V N
VN
Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia. vdumenko@yandex.ru
Kozlov
M K
MK
Kurova
N S
NS
Cheremushkin
E A
EA
D000328:Adult; D001931:Brain Mapping / Q000379:methods; D002540:Cerebral Cortex / Q000502:physiology*; D003071:Cognition; D004569:Electroencephalography; D004644:Emotions; D005149:Facial Expression; D005260:Female; D006801:Humans; D008297:Male; D012718:Set, Psychology