The ability to successfully form memories for arbitrary associations is essential for most acts of daily living. Numerous studies have shown that the hippocampus plays a critical role in associative memory. Recent work indicates that the perirhinal cortex (PRc) is also involved, but its functional role in associative memory is poorly understood. This research program will use functional magnetic resonance imaging (FMRI) and novel behavioral paradigms to test three theories of how the PRc contributes to associative recognition: (1) Unitization theory asserts that the PRc can support familiarity-based recognition of novel associations if the paired items are encoded as a single unit, but that the hippocampus is required for recollection of relations between items that are encoded as separate units. Novel FMRI experiments are proposed to test whether the PRc specifically contributes to recognition of associations between pairs of items that were encoded as a single unit. Parallel behavioral studies will test whether unitization influences indices of familiarity. (2) Domain theory asserts that the PRc supports familiarity-based recognition for associations between items from the same processing domain, but that the hippocampus is required to support recollection for associations between items from different processing domains. Novel FMRI studies are proposed to test whether the PRc supports associations between items from the same processing domains, but not associations between items from different domains. In addition, behavioral studies will test whether within-domain, but not across-domain associations influence the behavioral indices of familiarity. (3) Binding of items and contexts (BIC) theory asserts that the PRc represents item information, the PHc represents context information, and that this information is bound by the hippocampus. FMRI experiments are proposed to test whether recall of item information will be associated with PRc activity, whereas the recall of contextual information will lead to PHc activity. By testing the three theories, this proposal can provide the foundation for the development of a comprehensive theory of MTL function that can incorporate the influences of encoding processing, stimulus domain, and retrieval processing. Several psychiatric (e.g., schizophrenia) and neurological (e.g., Alzheimer's disease and traumatic brain injury) disorders are associated with memory impairments and with medial temporal lobe dysfunction. The proposed research may lead to improved diagnostic and therapeutic approaches to these disorders.

Public Health Relevance

Basic research on the mnemonic functions of the medial temporal lobe region is critically important because several psychiatric (e.g., schizophrenia) and neurological (e.g., Alzheimer's disease and traumatic brain injury) disorders are associated with memory impairments and MTL dysfunction. Such memory disorders can have a devastating effect on patients'quality of life. Research clarifying the basic neural mechanisms of memory can lead to improved diagnosis and treatment of these disorders.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Project (R01)
Project #
3R01MH083734-01A1S1
Application #
7928351
Study Section
Neurobiology of Learning and Memory Study Section (LAM)
Program Officer
Osborn, Bettina D
Project Start
2008-12-10
Project End
2011-09-13
Budget Start
2009-09-30
Budget End
2011-09-13
Support Year
1
Fiscal Year
2009
Total Cost
$535,645
Indirect Cost
Name
University of California Davis
Department
Neurosciences
Type
Schools of Arts and Sciences
DUNS #
047120084
City
Davis
State
CA
Country
United States
Zip Code
95618
Ritchey, Maureen; McCullough, Andrew M; Ranganath, Charan et al. (2017) Stress as a mnemonic filter: Interactions between medial temporal lobe encoding processes and post-encoding stress. Hippocampus 27:77-88
Koen, Joshua D; Barrett, Frederick S; Harlow, Iain M et al. (2017) The ROC Toolbox: A toolbox for analyzing receiver-operating characteristics derived from confidence ratings. Behav Res Methods 49:1399-1406
Koen, Joshua D; Borders, Alyssa A; Petzold, Michael T et al. (2017) Visual short-term memory for high resolution associations is impaired in patients with medial temporal lobe damage. Hippocampus 27:184-193
Harlow, Iain M; Yonelinas, Andrew P (2016) Distinguishing between the success and precision of recollection. Memory 24:114-27
Wang, Shao-Fang; Ritchey, Maureen; Libby, Laura A et al. (2016) Functional connectivity based parcellation of the human medial temporal lobe. Neurobiol Learn Mem 134 Pt A:123-134
Koen, Joshua D; Yonelinas, Andrew P (2016) Recollection, not familiarity, decreases in healthy ageing: Converging evidence from four estimation methods. Memory 24:75-88
Kolarik, Branden S; Shahlaie, Kiarash; Hassan, Abdul et al. (2016) Impairments in precision, rather than spatial strategy, characterize performance on the virtual Morris Water Maze: A case study. Neuropsychologia 80:90-101
Yushkevich, Paul A; Amaral, Robert S C; Augustinack, Jean C et al. (2015) Quantitative comparison of 21 protocols for labeling hippocampal subfields and parahippocampal subregions in in vivo MRI: towards a harmonized segmentation protocol. Neuroimage 111:526-41
Ritchey, Maureen; Montchal, Maria E; Yonelinas, Andrew P et al. (2015) Delay-dependent contributions of medial temporal lobe regions to episodic memory retrieval. Elife 4:
McCullough, Andrew M; Ritchey, Maureen; Ranganath, Charan et al. (2015) Differential effects of stress-induced cortisol responses on recollection and familiarity-based recognition memory. Neurobiol Learn Mem 123:1-10

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