Our ability to interpret visual scenes involves assembling the components of objects into a unified percept and segregating them from background, storing information about earlier visual experiences and testing our interpretations of the visual world against incoming sensory input.
The influences of context, experience and expectation are reflected in the response properties of cells at early stages in the visual pathway. The responses of cells in primary visual cortex depend not only on the attributes of features lying within the classical receptive field but also on
the global characteristics of the contours and surfaces within which these features are embedded. The substrate for lateral interactions includes a plexus of long‐range horizontal connections within each cortical area that links columns of similar orientation specificity and cells with
widely separated receptive fields. The horizontal connections also play a role in the plasticity of receptive field structure and of cortical functional architecture, induced over long time scales by retinal lesions and over short time scales by patterned visual stimulation. The long‐term
changes are associated with synaptogenesis; and the short‐term changes with an increase in synaptic effectiveness. The dynamics of cortical function persist throughout adulthood and are general to all cortical areas, including primary sensory cortices.