Effects of prolonged mental work on functional brain topography.
Topographic patterns of event-related covariance between electrodes were measured from subjects performing a difficult memory and fine-motor control task for 10-14 h. Striking changes occurred in the patterns after subjects performed the task for an average of 7-9 h, but before performance deteriorated. Pattern strength was reduced in a fraction-of-a-second-long response preparation interval over midline precentral areas and over the entire left hemisphere. By contrast, pattern strength in a succeeding response inhibition interval was reduced over all areas. The pattern changed least in an intervening interval associated with visual-stimulus processing. This suggests that, in addition to the well-known global reduction in neuroelectric signal strength, functional neural networks are selectively affected by sustained mental work in specific fraction-of-a-second task intervals.
Gevins
A S
AS
EEG Systems Laboratory, San Francisco, CA 94107.
Bressler
S L
SL
Cutillo
B A
BA
Illes
J
J
Miller
J C
JC
Stern
J
J
Jex
H R
HR
D000704:Analysis of Variance; D001519:Behavior / Q000502:physiology; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D004192:Discrimination, Psychological / Q000502:physiology; D004566:Electrodes; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008606:Mental Processes / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time; D013647:Task Performance and Analysis; D013997:Time Factors