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Hippocampal gamma‐band Synchrony and pupillary responses index memory during visual search
Author(s) -
MontefuscoSiegmund Rodrigo,
Leonard Timothy K.,
Hoffman Kari L.
Publication year - 2017
Publication title -
hippocampus
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.767
H-Index - 155
eISSN - 1098-1063
pISSN - 1050-9631
DOI - 10.1002/hipo.22702
Subject(s) - hippocampal formation , hippocampus , neuroscience , psychology , pupillary response , local field potential , cognitive psychology , pupil
Memory for scenes is supported by the hippocampus, among other interconnected structures, but the neural mechanisms related to this process are not well understood. To assess the role of the hippocampus in memory‐guided scene search, we recorded local field potentials and multiunit activity from the hippocampus of macaques as they performed goal‐directed search tasks using natural scenes. We additionally measured pupil size during scene presentation, which in humans is modulated by recognition memory. We found that both pupil dilation and search efficiency accompanied scene repetition, thereby indicating memory for scenes. Neural correlates included a brief increase in hippocampal multiunit activity and a sustained synchronization of unit activity to gamma band oscillations (50–70 Hz). The repetition effects on hippocampal gamma synchronization occurred when pupils were most dilated, suggesting an interaction between aroused, attentive processing and hippocampal correlates of recognition memory. These results suggest that the hippocampus may support memory‐guided visual search through enhanced local gamma synchrony. © 2016 Wiley Periodicals, Inc.