Phase-locked alpha and theta oscillations generate the P1-N1 complex and are related to memory performance.
An oscillatory phase resetting model is presented and data are reported which indicate that early components of the event-related potential are due to the superposition of evoked oscillations. The following hypotheses were tested and could be confirmed: (i) theta and alpha show a significant increase in phase locking during the time window of the P1 and N1 as compared to a prestimulus reference, (ii) the dynamics of event-related changes in evoked theta and alpha power obey the same principles as are known from event-related de-/synchronization research, and (iii) latency measures of the P1-N1 complex are negatively correlated with individual alpha frequency. In addition, we have found that theta phase locking is larger during encoding than recognition and that good memory performers show a larger increase in theta and alpha phase locking during recognition in the time window of the N1. Our general conclusion is that the P1-N1 complex is generated primarily by evoked alpha and theta oscillations reflecting the synchronous activation of a working- and semantic memory system.
Klimesch
Wolfgang
W
Department of Physiological Psychology, University of Salzburg, Institute of Psychology, Hellbrunnerstr. 34, A-5020 Salzburg, Austria. wolfgang.klimesch@sbg.ac.at
Schack
Bärbel
B
Schabus
Manuel
M
Doppelmayr
Michael
M
Gruber
Walter
W
Sauseng
Paul
P
D000328:Adult; D000513:Alpha Rhythm / Q000379:methods*; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013826:Theta Rhythm / Q000379:methods*