.I approach also crystallised Marr’s computational theory.

Marr (1982) was a cognitive scientist who followed the connectionist and semantic networks. The computational theory displays visual perception and identifies it as a complex information processing task (Marr, 1982). This approach is split into a Tri-level hypothesis; the algorithmic level, the implementational level and finally the computational level. Churchland, Koch and Sejnowski, (1990) have highly criticised the tri level hypothesis as being “fundamentally simplistic” as each level can be further sub-divided into further levels. According to Warren, Marr explained in further detail Gibson’s theory of perception, however he left out all natural constraints. At the algorithmic and implementational levels Marr failed to understand that vision is more complex and harder than the A.I approach first theorised (Freidenberg, 2010). Warrington and Taylor, (1978) found that brain damaged patients who have problems with object recognition cannot turn viewpoint dependent 2.5D sketches into 3D objects. Object recognition is achieved when the viewed image matches a representation of a known object stored in the brain, a top down approach. This supports the computational theory of visual perception, as different stages of processing are used to achieve the overall view of how object recognition is being perceived. Lappin et al, (2011) stated individual differences, such as brain damage were not taken into consideration in the approach as it was only a generalised theory. Dawson, (1998) found information processing occurs in both connectionist and classical systems and this implies Marr’s tri-level hypothesis can be applied equally to both approaches.

The connectionist approach differs from cognitive science as it theorises that knowledge is represented as a pattern of activation distributed through a network and is more global than a localised symbol. In regards to processing, connectionists suggest it occurs parallel through simultaneous activation of nodes in the network. Jerry Fodor (1980) argued that connectionism threatened to obliterate progress in the classical approach made fro