Relevance of EEG alpha and theta oscillations during task switching.
In a task switching design, we investigated the question whether long-range theta coupling primarily reflects top-down control processes. Switch and stay trials did not differ with respect to memory load or global working memory (WM) demands. The results revealed significantly stronger theta coupling (in a range of 4-7 Hz) between prefrontal and posterior regions during switch as compared to stay trials. Power differences, reflecting more local effects, were largest in the upper alpha band (10-13 Hz) and over posterior brain areas, possibly reflecting long-term memory activation. The conclusion of the present study is that long-range coherent oscillatory activity in the theta band reflects top-down activation rather than global WM functions.
Sauseng
P
P
Department of Psychology, University of Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria, Europe. paul.sauseng@sbg.ac.at
Klimesch
W
W
Freunberger
R
R
Pecherstorfer
T
T
Hanslmayr
S
S
Doppelmayr
M
M
D000328:Adult; D000513:Alpha Rhythm; D000704:Analysis of Variance; D001921:Brain / Q000502:physiology; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010775:Photic Stimulation; D011237:Predictive Value of Tests; D013826:Theta Rhythm; D013997:Time Factors