A central feature of episodic memories is that each item to be remembered is associated with a specific context-a time, place, and situation. According to the BIC model of MTL function (Diana, Ranganath, &Yonelinas, 2007), three regions in the medial temporal lobes (MTL)-the perirhinal cortex (PRc), parahippocampal cortex (PHc), and the hippocampus-make qualitatively different contributions to the encoding of item information, context information, and the binding of items to episodic context, respectively. Alternative MTL models exist, however the BIC model is unique in its focus on differentiating the roles of the PRc and PHc. PHc function is the least well understood of the MTL subregions. The BIC model makes predictions both for the role of PHc in memory and the cognitive relationships between item and context information that can affect memory. This application will test the BIC model's predictions about the cognitive and neural bases of episodic memory.
Specific Aims : 1)To examine the dynamics of episodic information, testing the cognitive hypothesis that item and context information are typically represented as separate pieces of information but can be unitized under specific encoding conditions. We will use ERP and behavioral methods to explore these cognitive questions regarding item and context information in memory. 2) To test the neural hypothesis that PHc and PRc activations are dissociable and are differentially involved in encoding of context representations and item representations, respectively. We will use fMRI methodology to dissociate the functions of PHc and PRc in memory. 3) To identify the nature of context information represented in the PHc, testing the neural hypothesis that PHc encodes spatial, semantic, and temporal context information. We will use fMRI methodology to define the nature of memory representations in PHc. The proposed projects will provide training in ERP, fMRI, and patient methodologies, enabling me to pursue my goal of becoming an independent investigator of the cognitive neuroscience of human memory. I intend to complete my training through two additional years of postdoctoral research and then obtain a position at a major research university to continue my research.
