Psychology Colloquia

Abstract:: Declarative memory permits an organism to bridge the past with the present, providing information about prior events that serves to inform present decisions and action. Declarative memory critically depends on the medial temporal lobe (MTL), which is composed of the hippocampal formation and the surrounding entorhinal, perirhinal, and parahippocampal cortices. Though decades of research have aimed to characterize the role of the MTL in declarative memory, fundamental questions remain regarding the functional contributions of specific MTL substructures. In this talk, I will discuss fMRI and MEG data bearing on the relative contributions of the hippocampus and the surrounding MTL cortices. These data support four central conclusions. First, item recognition and event recollection both vary in a continuous manner. Second, a functional gradient exists within the MTL circuit, wherein variability in memory for items and for item-context conjunctions differentially correlates with activation in perirhinal cortex and hippocampus, respectively. Third, the conjunctive memories built by hippocampus are flexibly addressable, enabling memory-based inferences and the encoding of conjunctive representations that integrate across events. Fourth, the circuitry of the hippocampus enables it to signal novelty via the detection of conjunctive prediction errors. Through its role in learning and remembering, the MTL not only empowers organisms to learn from the past to predict the present, but also to acquire new knowledge when predictions are violated.

For More Information About This Speaker:

http://psychology.stanford.edu/~wagner/
Dr. Wagner's website.

University of California, San Diego
Homepage Calendar Directions Past Events Psych Homepage UCSD Homepage	The Department of Psychology is Honored to Present a Talk by Anthony Wagner Stanford University "Remembering Events Pasts: Items, Conjunctions, Inference, and Errors in the Human MTL" Presented on May 24, 2007 Location: The Crick Conference Room Mandler Hall, room 3545 Abstract: Declarative memory permits an organism to bridge the past with the present, providing information about prior events that serves to inform present decisions and action. Declarative memory critically depends on the medial temporal lobe (MTL), which is composed of the hippocampal formation and the surrounding entorhinal, perirhinal, and parahippocampal cortices. Though decades of research have aimed to characterize the role of the MTL in declarative memory, fundamental questions remain regarding the functional contributions of specific MTL substructures. In this talk, I will discuss fMRI and MEG data bearing on the relative contributions of the hippocampus and the surrounding MTL cortices. These data support four central conclusions. First, item recognition and event recollection both vary in a continuous manner. Second, a functional gradient exists within the MTL circuit, wherein variability in memory for items and for item-context conjunctions differentially correlates with activation in perirhinal cortex and hippocampus, respectively. Third, the conjunctive memories built by hippocampus are flexibly addressable, enabling memory-based inferences and the encoding of conjunctive representations that integrate across events. Fourth, the circuitry of the hippocampus enables it to signal novelty via the detection of conjunctive prediction errors. Through its role in learning and remembering, the MTL not only empowers organisms to learn from the past to predict the present, but also to acquire new knowledge when predictions are violated. For More Information About This Speaker: http://psychology.stanford.edu/~wagner/ Dr. Wagner's website.
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