[Detection of mental task-induced changes in EEG patterns by detrended fluctuation analysis (DFA)].
The detection of mental task-induced changes in electroencephalograms (EEGs) is a challenge. We herein attempted to identify such changes with a long-range correlation parameter, represented as a scaling exponent estimated by detrended fluctuation analysis (DFA). Each of ten volunteers (6 males and 4 females, aged from 23 to 59 years old) was asked to perform two different one minute tasks with an interval between the two while EEGs were recorded: one was to a serial multiplication by 2 (2, 4, 8, 16 ....), and the other, imaginary drawing of a landscape. Five-second segments of EEG data recorded before, during, and after each of the two mental tasks were applied to DFA. The scaling exponent significantly decreased at the right occipital position while imagining the drawing (p = 0.026, by paired t test). Our results suggest that the DFA scaling exponent may be a useful parameter to detect mental task-induced EEG changes.
Central Clinical Laboratory, Nara Medical University Hospital, Kashihara.
Ryuko
R
Imai
Yasuyuki
Y
Okamoto
D000328:Adult; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D008875:Middle Aged