Effects of sectioning the corpus callosum on interocular transfer in hooded rats

Summary After learning a vertical/horizontal visual discrimination with one eye rats were tested on the same or the reverse discrimination with the second eye. Positive but imperfect savings were found in transfer rats and zero savings in reversal rats. However, there were no differences between the savings scores of normal rats and rats with section of the corpus callosum. When the first eye was subsequently retested, the normal rats which had learned the reverse discrimination with the second eye were significantly worse than those tested on transfer with the second eye, whereas no such difference occurred in the operated groups. It is argued that the uncrossed optic pathway is responsible for the indistinguishable performance of normal and operated rats on second eye performance, but that performance when the first eye is retested is now influenced by callosal fibres connecting primary traces in each hemisphere.