A remarkable act of memory entails binding different forms of information. We focus on the timeless question of how the bound engram is accessed such that its component features-item and context-are extracted. To shed light on this question, we investigate the dynamics between brain structures that together mediate the binding and extraction of item and context. Converging evidence has implicated the Parahippocampal cortex (PHc) in contextual processing, the Perirhinal cortex (PRc) in item processing, and the hippocampus in item-context binding. Effective connectivity analysis was conducted on fMRI data gathered during retrieval on tests that differ with regard to the to-be-extracted information. Results revealed that recall is initiated by context-related PHc activity, followed by hippocampal item-context engram activation, and completed with retrieval of the study-item by the PRc. The reverse path was found for recognition. We thus provide novel evidence for dissociative patterns of item-context unbinding during retrieval.
Bibliographical noteFunding Information:
Portions of this article are part of a doctoral dissertation submitted at Tel-Aviv University. We thank O. Linkovski and A. Spiegel and for assisting in data collection. We also thank an anonymous reviewer in the finer articulation of our ideas. This research was supported by The Israel Foundations Trustees (in part; Doctoral Grant No. 29 to T.S.); the Adams Super Center for Brain Studies in Tel-Aviv University (in part, to Y.G.G.); The Israel Science Foundation (in part; grant No. 1418/06 to A.M.); the European Community under the Marie Curie International Reintegration Grant (in part; MIRG-CT-2007-046457 to A.M.); The National Institute for Psychobiology in Israel — Founded by The Charles E. Smith Family (in part, to A.M); T.S. was supported in part by The Levy Edersheim Gitter Institute for Neuroimaging .
- Dynamic causal modeling (DCM)
- Medial temporal lobe (MTL)
- Parahippocampal cortex (PHc)
- Perirhinal cortex (PRc)
ASJC Scopus subject areas
- Cognitive Neuroscience