Effects of experience on interocular transfer of pattern discriminations in split-chiasm and split-brain cats.

Interocular transfer of monocularly learned pattern discriminations was found to be imperfect in split-chiasm cats but to improve as a result of specific practice with interocular transfer tasks. Section of the forebrain commissures subsequently performed in these animals abolished immediate interocular transfer of pattern discriminations. However, there were some savings in reattaining the learning criterion with the second eye. Other cats that learned the same discriminations monocularly but had sustained a combined section of optic chiasm and forebrain commissures before learning showed no indication of interocular transfer. These data suggest that the commissural systems involved in interocular and interhemispheric transfer of pattern discriminations may be modified by practice and learning. Further, it is possible that the intervening transfer experience between the section of the optic chiasm and that of the forebrain commissures results in the persistence of some capacity for interocular transfer of pattern discriminations after commissurotomy. However, this residual capacity may be negligible when compared with the capacity for interocular transfer of split-chiasm cats with intact forebrain commissures.