A central question in memory research is how component structures of medial temporal lobe (MTL) differentially contribute to acquisition, retention, and retrieval of long-term memories. Using a combination of high-resolution fMRI and cortical flattening techniques that make differentiation of these small, adjacent structures possible, the proposed research investigates hypotheses regarding functional specialization within MTL. The proposed experiments specifically investigate hypotheses based on the connectional anatomy of MTL, both in terms of its connectivity to sensory cortical regions and its intrinsic hierarchical connectivity. The segregation of cortical information entering MTL suggests that different MTL subregions may maintain different types of memory representations since each region has a unique set of inputs allowing for a distinctive pattern of sensory convergence and integration that support different types of representational capabilities. In addition, the hierarchical nature of processing in MTL suggests that structures at different hierarchical levels play distinct roles in declarative memory. First, we will test whether encoding responses and subsequent memory prediction of MTL subregions depend on cortical information that each subregion receives. Second, we will examine how different MTL subregions are involved in item and relational memory at encoding and retrieval. Finally, we will consider how MTL subregions contribute to acquisition and use of conjunctive information. ? ?
Preston, Alison R; Bornstein, Aaron M; Hutchinson, J Benjamin et al. (2010) High-resolution fMRI of content-sensitive subsequent memory responses in human medial temporal lobe. J Cogn Neurosci 22:156-73 |