Visual control of an action discrimination in pigeons

Abstract

Recognizing and categorizing behavior is essential for all animals. The visual and cognitive mechanisms underlying such action discriminations are not well understood, especially in nonhuman animals. To identify the visual bases of action discriminations, four pigeons were tested in a go/no-go procedure to examine the contribution of different visual features in a discrimination of walking and running actions by different digital animal models. Two different tests with point-light displays derived from studies of human biological motion failed to support transfer of the learned action discrimination from fully figured models. Tests with silhouettes, contours, and the selective deletion or occlusion of different parts of the models indicated that information about the global motions of the entire model was critical to the discrimination. This outcome, along with earlier results, suggests that the pigeons’ discrimination of these locomotive actions involved a generalized categorization of the sequence of configural poses. Because the motor systems for locomotion and flying in pigeons share little in common with quadruped motions, the pigeons’ discrimination of these behaviors creates problems for motor theories of action recognition based on mirror neurons or related notions of embodied cognition. It suggests instead that more general motion and shape mechanisms are sufficient for making such discriminations, at least in birds.

Pigeons (Columba livia) fail to connect dots in learning biological motion

“…In summary, consistent with previous studies (Dittrich et al 1998;Qadri et al 2014), the present study provides another case in which the pigeons, unlike humans, seem to fail to make the connection between the full-detail displays and their point-light counterparts even if the common motion features of stimuli are available as a cue. Contrary to our prediction, the motion-congruent group showed poorer transfer to point-light displays compared with the motion-incongruent group.…”

“…Previous studies reported that pigeons failed to transfer motion discrimination to point-light displays (Dittrich et al 1998;Qadri et al 2014). In those studies, the overall dissimilarity of point-light and full-detail displays greatly reduced peck rates to the point-light displays during transfer tests, resulting in poor discrimination of the pointlight test stimuli.…”

“…One interpretation for such unidirectional transfer is that pictorial cues in the full-detail displays facilitate perceptual grouping of multiple point lights into a single unity, which may be otherwise difficult to perceive. A more recent study also demonstrated that pigeons trained to discriminate two different actions of dogs and bucks in full-detail displays failed to transfer this learning to point-light ones (Qadri et al 2014). …”

Experimental Divergences in the Visual Cognition of Birds and Mammals

“…That the processing of PLDs and full-figured complete displays is not equivalent is further supported by studies of action recognition using digital models (Asen & Cook, 2012; Qadri, Asen, & Cook, 2014; Qadri, Sayde, & Cook, 2014). After training pigeons to discriminate complete, digitally rendered animal models engaged in either walking or running actions (Asen & Cook, 2012), Qadri, Asen, and Cook (2014) found that the discrimination of these action categories did not transfer to PLD models that were built using the same articulated structure, motion, and background as the trained actions.…”

“…After training pigeons to discriminate complete, digitally rendered animal models engaged in either walking or running actions (Asen & Cook, 2012), Qadri, Asen, and Cook (2014) found that the discrimination of these action categories did not transfer to PLD models that were built using the same articulated structure, motion, and background as the trained actions. This result persisted across differences in the size of the defining dots and changes in the overall visual angle of the display, both changes designed to promote the perceptual grouping of the separated dots.…”