Title: Discrimination of speed and direction of rotation in the pigeon: A mirror-image effect
Abstract: Pecks to a 15-rpm clockwise visual stimulus were reinforced on a mult VI 30-sec EXT schedule. Pecks were extinguished in the presence of: Part A, a dark key; Part B, a 10-rpm clockwise stimulus; Part C, a 15-rpm counterclockwise stimulus. In Parts A and B, the results indicated that responding to counterclockwise rotations mirrored the pattern of responding to clockwise rotations. In Part C a different pigeon learned to discriminate between clockwise and counterclockwise rotations, but generalization tests 5 and 12 days after the original tests showed emergence of the mirror effect noted in the first two parts.