Backward spreading of memory-retrieval signal in the primate temporal cortex.
Bidirectional signaling between neocortex and limbic cortex has been hypothesized to contribute to the retrieval of long-term memory. We tested this hypothesis by comparing the time courses of perceptual and memory-retrieval signals in two neighboring areas in temporal cortex, area TE (TE) and perirhinal cortex (PRh), while monkeys were performing a visual pair-association task. Perceptual signal reached TE before PRh, confirming its forward propagation. In contrast, memory-retrieval signal appeared earlier in PRh, and TE neurons were then gradually recruited to represent the sought target. A reasonable interpretation of this finding is that the rich backward fiber projections from PRh to TE may underlie the activation of TE neurons that represent a visual object retrieved from long-term memory.
Naya
Y
Y
Laboratory of Cognitive Neuroscience, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan.
Yoshida
M
M
Miyashita
Y
Y
D000200:Action Potentials; D000818:Animals; D001931:Brain Mapping; D003463:Cues; D008032:Limbic System / Q000502:physiology; D008251:Macaca; D008568:Memory / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*; D014795:Visual Pathways; D014796:Visual Perception