Evaluate the evidence that visual perception involves bottom-up and top-down processing.
The perceptual system is comprised of a of a diverse range of senses including visual, auditory, olfactory and tactition; the perceptual system is part of the nervous system, which contains millions of nerve cells called receptors that sense and respond to a plethora of sensory stimuli including light, sound and temperature. The act of perceiving rather than merely sensing enables us to analyse and make sense of incoming sensory information, allowing us to construct a description of the environment to inform and guide our actions within a complex, dynamic world. For primates, as compared to other species, vision has predominantly been relied…show more content… The vibrant environment to which Gibson refers is composed of images and surfaces with varying densities, textures, sizes, distances and shapes, and the interaction or movement of the observer and the movement of the object provide ample information to generate perception.
Gibson emphasises the significance of what he terms the ‘optic array’ whereby light reflected from a multitude of textured surfaces unites in the visual field occupied by the observer, thus altering in conjunction with the position of the observer, hence providing information about where the object is in space. Furthermore, Gibson purposed that in addition to the optic array, invariants or higher-order features, such as ‘horizon ration relation’ and ‘texture gradient’ offer explicit insight into the nature of the environment (as cited in Pike & Edgar, 2010, pp 74-76). ‘Horizon ration relation’ explored by Sedgwick (1973) enables us to judge relative heights and distances of objects; the distance of objects can be judged as the ratio of the proportion of the horizon above to below the object remains constant, however if objects viewed at the same distance differ in height the overall height of the horizon correspondingly increases (as cited in Pike & Edgar, 2010 pp 74-76). Likewise, texture gradient provides information about the density, height, and width of individual elements contained within and varying from surface to surface. Additionally Gibson posits motion and