| Citation | Brown is distinguished for his electrophysiological studies into the neural basis of learning and memory. By recording the activity of single neurones in unanaesthetised monkeys performing recognition memory tasks, he and his colleagues discovered in perirhinal cortex adjacent to the hippocampus neuronal responses that encode types of information crucial for long-term recognition memory. He established that these responses can separably encode information concerning the relative familiarity and recency of occurrence of visual stimuli. Moreover, the location of the neurones, in cortex adjacent to rather than within the hippocampus, first clearly signalled the importance of perirhinal cortex for such recognition memory processes. Appreciation of this importance resulted in a radical reappraisal of previous ideas concerning memory mechanisms in the temporal lobe. No other known neuronal changes within perirhinal cortex provide a substrate for general familiarity discrimination. In other studies Brown first described the signalling of contextual information by neurones of the hippocampal formation and his recent work in the rat has demonstrated a double dissociation between the role of the hippocampal formation in recognition memory for spatial arrangements of items and that of the perirhinal cortex in recognition memory for individual items. Furthermore, work with other collaborators, involving recordings from unanaesthetised behaving chicks has greatly advanced understanding of neural processes underlying the recognition memory of imprinting. |