BrainMap: Michael Yassa, PhD; Functional Specialization in the Human Medial Temporal Lobes: Insights from High-Resolution Imaging Studies

Michael Yassa, PhD

Assistant Professor

UC Irvine

Title:  Functional Specialization in the Human Medial Temporal Lobes: Insights from High-Resolution Imaging Studies
 
Abstract: I will share some of our lab’s most recent data regarding the computational division of labor in the medial temporal lobes, including the hippocampus and surrounding regions. Using a combination of highly targeted cognitive tasks and high resolution functional imaging, we demonstrate that hippocampal subfields play dissociable roles in serving episodic memory in humans, consistent with animal and computational models. In addition to subfield computations (e.g. pattern separation and pattern completion), we demonstrate new evidence of a dissociation according to information content (e.g. object vs. spatial memory) in hippocampal afferent/efferent connections (lateral vs. medial entorhinal cortex, and perirhinal vs. parahippocampal cortex) that maps directly onto results from animal recording data. We also demonstrate evidence for a dorsoventral axis in the hippocampus that is a graded continuum of memory construction with highly specific detailed memory being supported by the dorsal (posterior) hippocampus and more generalized online representations being supported by the ventral (anterior) hippocampus. Finally, we report evidence of a hippocampal-thalamic-prefrontal network for repetition-mediated consolidation of information, consistent with recent data from physiological recordings in animals.