Visual discrimination of the orientation of rectangles by Octopus Vulgaris Lamarck.

Abstract

16 octopuses were trained on successive visual discriminations between rectangles in horizontal, vertical, and oblique positions. Vertical-horizontal discriminations were the most accurately made, discriminations between 2 opposite oblique forms the least accurate. The results are taken as consistent with the hypothesis that the octopus classifies shapes by analyzing their lateral and vertical extents at different points on the horizontal and vertical axis. From Psyc Abstracts 36:01:1EJ52S. (PsycINFO Database Record (c) 2006 APA, all rights reserved)