Inferential constraint sets in the organization of visual expectation.

Many lines of evidence indicate that considering visual perception as a passive, stimulus-driven, feedforward decoding process is no longer tenable. Visual perception naturally occurs within the context of an integrated array of ongoing cognitive processes involving memory, perception in other modalities, and motor control. In many situations, these processes allow expectations to be formed for likely visual events. This article explores the idea that the formation of visual expectations involves the active organization of visual cortical areas, providing a framework of contextual information within which expected events are interpreted. Retinal inputs are treated as constraints that feed into a complex system of interacting visual cortical areas and thalamic nuclei, which are concurrently imposing constraints on one another. Although the nature of expectational organization in the visual cortex is not well-understood, a reasonable hypothesis is that expectation involves the mutual constraint of spatiotemporal activity patterns in multiple visual cortical areas. In this scenario, expectation is instantiated by a set of activity patterns in high-level visual cortical areas that impose constraints on one another as well as on low-level areas according to the partial information that is available about expected retinal inputs. One approach to testing this proposal is through the analysis of simultaneously recorded local field potentials (LFPs) from local neuronal assemblies in multiple visual cortical areas. Analysis of LFPs by multivariate autoregressive modeling is showing promise in revealing the organization of expectation in visual cortex.