Visual Processing: A Complex System

Visual processing is a complex system within the brain and is devised of many neural circuits that carry information. The retina receives information which is transported in a hierarchical process through different levels of the brain including the thalamus, Primary Visual Cortex and Visual Association Cortex. The neural circuits meet and associations form, through a top-down and bottom-up process, enabling visual perception to take place. Various studies, for example brain damaged patients, have been carried out in order to explore the functions of different cells within the brain, neural circuits and regions in the brain responsible for different aspects of the visual processing. Arguably, attention has to be paid to the visual field, during which the brain picks out specific parts and

In both of these regions, information from the different neural circuits is collaborated. Information from the Parvocellular Pathway, which transports information mostly about colour, orientation and line widths, amalgamates in the temporal lobe. Meanwhile, information about movement as well as information from both eyes, transported by the Magnocellular pathway merges in the parietal lobe. This allows us to perceive location and movement as well as three-dimensional form.

Once the information reaches the point of being integrated it is questionable how the information is perceived. There is controversial debate about whether visual processing is bottom-up, top-down or both. Bottom-up processing is the idea of a hierarchical structure within the visual system, from which information travels from the retina to the highest levels of processing (as previously described). Top-down processing, however, is where contextual information is sent from higher levels of processing is transferred to lower levels to aid