Induced gamma band responses: an early marker of memory encoding and retrieval.
Although mnemonic processes have been widely studied using event-related potentials (ERPs), memory-related oscillatory changes in the EEG have been relatively neglected. The aim of this study was to investigate memory encoding- and retrieval-related changes in the frequency domain. In particular, we focused on induced gamma band responses (GBRs), which are a candidate for the establishment and activation of widespread cell assemblies. At encoding, results revealed increased GBRs for subsequently recognised relative to subsequently forgotten items. At retrieval, recognised old stimuli were associated with higher GBRs compared to new stimuli. During encoding and retrieval GBR modulation preceded that of ERPs. Thus, GBRs might be a correlate of processes that onset earlier to those responsible for memory encoding and retrieval ERP effects.
Gruber
Thomas
T
Institut für Allgemeine Psychologie, Universität Leipzig, Seeburgstrasse 14-20, 04103 Leipzig, Germany. gruber@rz.uni-leipzig.de
Tsivilis
Dimitris
D
Montaldi
Daniela
D
Müller
Matthias M
MM
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D004569:Electroencephalography / Q000379:methods*; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods*; D011930:Reaction Time / Q000502:physiology