Neuronal tuning and associative mechanisms in form representation.

We examine the hypothesis that the form representation in the anterior inferotemporal (AIT) cortex is acquired through learning. According to this hypothesis, perceptual aspects of the temporal association area are closely related to its visual representation, in that the response selectivity of AIT neurons can be influenced by visual experience. On the basis of the neurophysiological evidence, we summarize two neuronal mechanisms that subserve the acquisition of form selectivity in AIT neurons. The first mechanism is neuronal tuning to particular stimuli that were learned in a cognitive task. The second mechanism is association, with which relevant information can be retrieved from other stored memories. On the grounds that long-term memory of objects is acquired and organized by at least these two neuronal mechanisms in the temporal association area, we further present a model of the cognitive memory system that unifies perception and imagery.