Electrophysiological dissociation of rapid memory mechanisms in humans.
Human memory involves an interaction between transient working memory and a long-term store. We found electrophysiological evidence supporting the existence of two distinct mechanisms subserving these processes. Stimuli held in memory for less than 4 s generate large, early latency P300 potentials which may index activation of a frontally-mediated rapid working memory system. Stimuli held in memory for over 4 s selectively generate N400 potentials which may reflect activation of mesial temporal cortices involved in access to the long-term store. These results suggest that memory processing in the initial 10 s after stimulus detection involves at least two distinct distributed cortical-limbic systems.
Nielsen-Bohlman
L
L
Department of Neurology, University of California, Davis.
Knight
R T
RT
D000328:Adult; D004569:Electroencephalography; D004594:Electrophysiology; D005071:Evoked Potentials; D005133:Eye Movements; D006801:Humans; D008297:Male; D008564:Membrane Potentials; D008568:Memory / Q000502:physiology*; D008570:Memory, Short-Term / Q000502:physiology*; D012016:Reference Values; D013997:Time Factors