Center for Science in Society

Science Matters

A weekly feature (begun November 2004) connecting Center activities to what's happening in the world at large.
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The 11/12 Brown Bag discussion of "History, Memory and the Brain" looked at the troubles that historians get into, given the human "vice" for nostalgia...and explored some alternatives...

"Hegel was right when he said that we learn from history that man can never learn anything from history." ~ George Bernard Shaw

"History is the version of past events that people have decided to agree upon." ~ Napoleon Bonaparte

Cognitive Memory: Cellular and Network Machineries and Their Top-Down Control
Yasushi Miyashita

A brain-wide distributed network orchestrates cognitive memorizing and remembering of explicit memory (i.e., memory of facts and events). The network was initially identified in humans and is being systematically investigated in molecular/genetic, single-unit, lesion, and imaging studies in animals. The types of memory identified in humans are extended into animals as episodic-like (event) memory or semantic-like (fact) memory. The unique configurational association between environmental stimuli and behavioral context, which is likely the basis of episodic-like memory, depends on neural circuits in the medial temporal lobe, whereas memory traces representing repeated associations, which is likely the basis of semantic-like memory, are consolidated in the domain-specific regions in the temporal cortex. These regions are reactivated during remembering and contribute to the contents of a memory. Two types of retrieval signal reach the cortical representations. One runs from the frontal cortex for active (or effortful) retrieval (top-down signal), and the other spreads backward from the medial temporal lobe for automatic retrieval. By sending the top-down signal to the temporal cortex, frontal regions manipulate and organize to-be-remembered information, devise strategies for retrieval, and also monitor the outcome, with dissociated frontal regions making functionally separate contributions. The challenge is to understand the hierarchical interactions between these multiple cortical areas, not only with a correlational analysis but also with an interventional study demonstrating the causal necessity and the direction of the causality.

Department of Physiology, University of Tokyo School of Medicine, Hongo, Tokyo 113-0033, Japan.

These pages have been created by Selene Platt in consultation with Paul Grobstein.
Please submit suggestions for other topics to explore in "Science Matters" to Selene Platt .