Interocular Transfer of Pattern-Discrimination in the Goldfish

Interocular Integration of Visual Learning by Goldfish

“…The success of conflict training in the present study seems, at first sight, to contradict the conclusions of Schulte [1957] and of Shapiro [1965], who failed to obtain such results with carp and goldfish. Schulte overtrained two fish on a 'cross vs. ring' problem, and then reversed this discrimination via the second eye over the course of several weeks.…”

“…A recent electrophysio logical study of the goldfish [Jacobsen and Gaze, 1964] confirms the anatomists' conclusion that only the contralateral optic tectum receives a direct projection from the retina. Nonetheless, visual information must reach the second brain half since fish that are trained monocularly to discriminate patterns or colors can retain these discriminations while using the untrained eye alone [Schulte, 1957;McCleary, 1960;Ingle, 1965;Shapiro, 1965;Mark, 1966], Successful interocular transfer indicates that each hemisphere has access to two kinds of visual input: (1) that received directly from one eye, via retinotectal or retinothalamic projections, and (2) that arriving indirectly via commissural pathways, which remain to be specified.…”

The Fish Telencephalon and Its Relation to Learning

“…Possibly this discrepancy in results is explained by difficulties experienced by the tectally split fish in transferring some motor components of the task. McCleary (1960) and Shapiro (1965) have both shown that the successful demonstration of transfer is dependent either on an easy problem or on careful pretraining of both eyes on the motor aspects of the paradigm. If the tectal commissure is involved to some degree in the transfer of motor information relating to an imperfectly learned task, then splits of this commissure may appear to impede transfer of responses to a discrimination.…”

Visual discrimination versus visuo-motor learning in interocular transfer in the fish

“…Despite complete crossing of the optic nerves, interocular transfer (IT) of learning has been demonstrated with several kinds of fish (Ingle, 1965;Schulte, 1957;Sharpiro, 1965;Sperry & Clark, 1949), However, lack of IT was found in goldfish when opaque eye caps were used to effect monocular vision and new swimming patterns were involved in the learning (McCleary ,1960), From this finding and some other supporting evidence, McCleary proposed that in fish IT occurs in passive visual discrimination (PD), but not in visuo-motor learning (VM) involving visually guided voluntary motor responses. This proposal fits the findings of the other studies where IT was demonstrated, because the motor responses involved were either the usual swim-to-food response, or were pretrained for both eyes.…”