Modulation of induced gamma band responses and phase synchrony in a paired associate learning task in the human EEG

It has been proposed that associative learning is accomplished by the formation of cell assemblies and synchronous activity among the neurons of such an assembly. Induced gamma band responses (GBRs) and phase synchrony between electrode sites are discussed as a signature of activity within a cell assembly. To examine the activation of this network due to memory recall, a paired associate learning paradigm was used. EEG was analyzed in the frequency domain. Results showed a significant increase of induced GBRs at posterior and anterior electrode sites in the recall sequence of the learning condition. Furthermore, phase synchrony revealed a broad distribution pattern of phase synchrony between posterior and frontal electrode sites.