Modularity of memory and the nervous system

Abstract

Memory seems not to be a single entity but a pool of several abilities mediated by distinct brain systems. Examination of available evidence allows distinction between short-term memory, working memory and long-term memory. Besides the existing task division into modules, which involves several processing units working in parallel, the final result is a unitary memory experience. Each module of memory maintains extensive connections with the others, and variable levels of independence between them are maintained. Lesions of independent modules break up their function, while lesions in modules which cooperate intimately produce an alteration of functioning in the unaffected ones in order to minimize deficiencies. This independent but cooperative functioning of modules can explain experimental dissociations after lesioning, and also the unitary memory experience in normal subjects. Data on lesioning of neural circuits that underly some modules of memory are analysed.