The Effect of Vertical Lobe Removal On the Performance of Octopuses in Retention Tests

Abstract

1. Octopuses were trained to make a tactile discrimination until they attained a criterion of either 75% or 85% correct responses in twenty successive trials. They were then overtrained for an equal number of trials. Retention of training was tested in twenty unrewarded trials with the same objects 5 or 10 days later. 2. Exactly similar experiments were made with animals trained after removal of the vertical lobes of their brains; these animals were slower to learn, but once trained to a similar standard of accuracy of response they forgot their training at the same rate as controls. 3. This shows that while the presence of the vertical lobe enhances the effect of experience on the establishment of memories causing discrimination of things touched, it does not affect the maintenance of these memories once established.