![]() With his failure to locate the site of learned discriminations by selective ablations of the cortex, and with his judicious reflections thereafter, he unwittingly laid the groundwork for a distributed substrate of memory. The neuropsychologist Karl Lashley2 was the first in modern times to recognize the futility of trying to Copyright © 1997, Elsevier Science Ltd. Neuropsychologists have refined their methods to match the localizationist precision of physiologists, while the latter have ventured into the cortex of association in the expectation of localizing memories, perceptions and attention there using the same procedures with which they had successfully identified feature detectors or minicolumns. In the past 50 years, the two currents have tended to converge. Subtly taking a theoretical position akin to phrenology, though legitimized by the scientific method, the investigators of the effects of cortical lesions in humans and animals have since then persistently attempted to localize cognitive functions, such as memory, in discrete cortical regions. Towards the end of the nineteenth century, another methodology began to develop in parallel with the physiological one: the lesion methodology. The use of electrical stimulation and recording methods led to ever increasing knowledge on the location of sensory and motor areas. ![]() The discovery of the motor cortex by Fritsch and Hitzig1 initiated a long tradition of studies intended to map the physiological functions of the cerebral cortex. The conceptual and empirical background for these tenets is reviewed in this article. ![]() These store memory in both the short and the long term. The same is true for the cortex, which has a posterior sensory region and a frontal motor one. Every stage of that hierarchy has two major components, each devoted primarily, if not exclusively, to one of the two basic organismic functions, sensing and acting. The cortical substrate of memory, and of knowledge in general, can be viewed as the upward expansion of a hierarchy of neural structures with its base in the spinal cord. The available evidence indicates that memories subsist in networks of interconnected and distributed neocortical neurons. In primates, the memory of past experience is stored largely in the neocortex – the phylogenetically newest part of the cerebral cortex. ![]() Thus, almost all regions of the brain store memory of one kind or another. HE CAPACITY TO STORE INFORMATION about oneself and one’s environment is present throughout the nervous system. Recall, recognition and working memory consist largely in their reactivation, also by association. Perceptual and motor memory networks are hierarchically organized in post-rolandic and pre-rolandic neocortex, respectively. Our memories are networks of interconnected cortical neurons, formed by association, that contain our experiences in their connectional structure. Fuster Our thinking on the cortical organization of primate memory is undergoing a copernican change, from a neuropsychology that localizes different memories in different areas to one that views memory as a distributed property of cortical systems.We are shifting our focus from ‘systems of memory’ to the memory of systems.The same cortical systems that serve us to perceive and move in the world serve us to remember it.
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