Lateralization of Learning of Colour and Brightness Discriminations following Brain Bisection

Abstract

SEVERAL investigations dealing with interocular transfer of learning of visual discriminations in split-brain cats and monkeys support the general conclusion that brain bisection including the optic chiasm and posterior corpus callosum restricts the learning and memory of the discriminations to the trained hemisphere. These tasks cannot be correctly performed through the other eye until it has received comparable training, in contrast to the immediate interocular transfer usually shown by normal or chiasm-sectioned controls^1–3. This generalization has been qualified by more recent studies indicating that transfer of learning of brightness^4,5 and pattern⁶ discriminations in split-brain cats, and of brightness and colour discriminations in split-brain monkeys⁷, does occur under certain conditions. Transfer of colour and brightness learning in split-brain monkeys would, therefore, seem to be dependent on the conditions used. It appeared advisable, in reference to future studies on vision, to see if transfer of these tasks takes place under the conditions at present being used in this laboratory.