ABSTRACT
In the enquiry into evolutionary changes in the visuo-motor system from hominoids to Homo sapiens, it is necessary to describe in outline our present understanding of the processing of visual information in the simian brain. The most intense study has been on the very complex visual system of the macaque (Macaca mulatta). Because it is essentially very similar to the visual systems of other higher primates, it is expedient to regard this visual system as the model for the hominoid visual system at the onset of hominid evolution. The Primates are extremely visual animals and already in their evolution simians had surpassed any other order of mammals. Their eyes project forwards, giving them complete binocular vision. As shown in Figure 6.1, the visual pathways are arranged with a partial decussation in the optic chiasma so that the right visual fields of the two eyes project via a synaptic relay in the lateral geniculate body (LGB) to the primary visual cortex (see Figure 4.4) (Brodmann area 17 or visual area V1) of the left occipital lobe, and vice versa for the left visual field.
