Object Unitization and Associative Memory Formation Are Supported by Distinct Brain Regions
Open Access
- 21 July 2010
- journal article
- Published by Society for Neuroscience in Journal of Neuroscience
- Vol. 30 (29), 9890-9897
- https://doi.org/10.1523/JNEUROSCI.0826-10.2010
Abstract
While it has been established that the medial temporal lobe (MTL) is critical for successful memory formation, the precise contribution of one of the key MTL subregions, the perirhinal cortex (PrC), has been the subject of intense focus and debate. Although this region has been implicated in nonassociative item encoding, recent neuroimaging data have revealed that it also contributes to the binding of specific item-related associations (e.g., an object–color association). Based on neuropsychological evidence that associative memory for unitized word pairs does not require the hippocampus, it has been proposed that PrC contributes to associative memory formation by means of unitization. However, the role of PrC in unitization processes remains unclear. Here, we used fMRI to assess the involvement of PrC in object unitization as well as in successful episodic encoding of item-related details. Our results show that while PrC activation linearly tracks the amount of item-related information successfully encoded, it is not modulated by object unitization demands. Instead, the present data reveal that unitization of object fragments may be accomplished in visual/ventral temporal processing stages before PrC. Indeed, we observed a gradual transition from unitization to successful memory formation across the ventral visual pathway. This suggests that PrC may specifically serve to encode item-related event details, whereas their perceptual integration is established along preceding processing stages.Keywords
This publication has 46 references indexed in Scilit:
- A backward progression of attentional effects in the ventral streamProceedings of the National Academy of Sciences, 2009
- Distortion and Signal Loss in Medial Temporal LobePLOS ONE, 2009
- Relational memory and the hippocampus: Representations and methodsFrontiers in Neuroscience, 2009
- Perirhinal Cortex Supports Encoding and Familiarity-Based Recognition of Novel AssociationsNeuron, 2008
- Selective and Shared Contributions of the Hippocampus and Perirhinal Cortex to Episodic Item and Associative EncodingJournal of Cognitive Neuroscience, 2008
- Content-specific source encoding in the human medial temporal lobe.Journal of Experimental Psychology: Learning, Memory, and Cognition, 2008
- The effects of unitization on familiarity-based source memory: Testing a behavioral prediction derived from neuroimaging data.Journal of Experimental Psychology: Learning, Memory, and Cognition, 2008
- The Medial Temporal Lobe and Recognition MemoryAnnual Review of Neuroscience, 2007
- The contribution of familiarity to associative memory in amnesiaNeuropsychologia, 2006
- Binding crossmodal object features in perirhinal cortexProceedings of the National Academy of Sciences of the United States of America, 2006