An Investigation of Reversal Learning in Octopus Vulgaris Lamarck

Abstract

Eighteen octopuses were trained by a method of successive discrimination training to discriminate between a vertical and a horizontal rectangle. They were then overtrained for either 20 or 60 trials, after which they learnt the reverse discrimination. At the beginning of each reversal they were given 20 trials pretraining on the new positive stimulus. The subjects completed from two to nine reversals. It was found that the amount of overtraining had no effect on the rate of learning the subsequent reversal. The first four reversals all took significantly longer to learn than the original problem, but did not differ significantly from one another. However, examination of the raw data suggests that later reversals do take longer to learn. The performance when learnt (i.e. on the first day of overtraining) was as good after reversal learning as after the learning of the original problem. The results do not show definite signs that could be interpreted as an exhaustion of a limited supply of neurones available for learning.