Improvement in habit reversal as related to dimensional set.

Abstract

Pigeons and fish (goldfish and African mouthbreeders) were trained in long series of 40-trial, 2-dimensional discriminative problems which required them sometimes to shift dimensions and sometimes to reverse within a dimension. Pure reversals were more difficult at the outset than reversal shifts, and reversal shifts were more difficult than nonreversal shifts. In pigeons, but not in fish, progressive improvement in reversal appeared as training continued, and the differences in difficulty among the 3 transitions tended to disappear. The implications of the results for an attentional interpretation of reversal learning are considered.