Information Storage in the Brain: A Study of Imprinting in the Domestic Chick

A number of more recent formulations (e.g., Milner, 1957; Griffith, 1966; Brindley, 1967; Marr, 1969) are variants on these basic themes: a particular experience or event leads to the formation or strengthening of pathways in the brain.

Abstract

It is not perhaps surprising that there is a long history of interest in the mechanisms by which information is stored in the brain. Superficially, the explanations that have been offered have varied down the centuries, but with few exceptions the explanations share a common theme: a particular experience or event leads to the formation or strengthening of pathways in the brain. Once established a pathway, or trace, becomes more easily activated and this activity leads to recall. Whilst recognizing that retention over relatively short periods of time could be achieved by transitory activity, long lasting memories have been thought to involve morphological changes in these pathways (see James, 1890). Descartes (1649) foreshadowed the idea of morphological change when he wrote that the traces were '...pores of the brain... (which had) acquired a greater facility than the rest to be opened again...'. Freud (1895) envisaged the existence of barriers between neurons of a certain class. He suggested that activation of these neurons led to an irreversible decline in the resistance of the barriers and hence to the formation of a memory trace. For Cajal (1911) the critical change was the formation of new connections. More recently Hebb (1949) proposed that repeated stimulation of specific receptors led to formation of an assembly of cells through the enlargement or development of synaptic boutons. This assembly (Hebb, 1949) '...constitutes the simplest instance of a representative process (image or idea)'. A number of more recent formulations (e.g., Milner, 1957; Griffith, 1966; Brindley, 1967; Marr, 1969) are variants on these basic themes.