Complex Learning and Information Processing by Pigeons: A Critical Analysis

Abstract

Three models of conditional discrimination learning by pigeons are described: stimulus configuration learning, the multiple-rule model, and concept learning. A review of the literature reveals that true concept learning is not characteristic of the behavior of pigeons in matching-to-sample, oddity-from-sample, or symbolic matching studies. Instead, pigeons learn a set of sample-specific SD rules. Transfer of the discrimination to novel stimuli, at least along the hue dimension, is predicted by a "coding hypothesis", which holds that pigeons make a unique, but usually unobserved response, R,, to each sample, and that the comparison stimulus chosen depends on which R1 was emitted in the presence of the sample. Convincing evidence is found that pigeons do code sample hues, but there is little evidence that allows one to infer that the "coding event" must have behavioral properties. Parameters of the conditional discrimination paradigm are identified, and it is shown that by appropriate parametric manipulation, a variety of analogous tasks may be generated for both human and animal subjects. The tasks make possible the comparative study of complex learning, attention, memory, and information processing, with the added advantage that behavior processes may be compared systematically across tasks.

Successive two-item same-different discrimination and concept learning by pigeons

“…These transfer results rule out the possibility that the discrimination was based on learning stimulus-specific associations (e.g. Carter and Werner, 1978;Wright, 1997Wright, , 2001). Instead, the positive transfer suggests the pigeons were responding to the general stimulus relations of same and different between successive items.…”

“…at least when pecked at directly by the birds (Carter and Werner, 1978;Wright, 1997;Young et al, 1997Young et al, , 1999. The central location of the objects may have been more problematic.…”

Learning Processes in Matching and Oddity: The Oddity Preference Effect and Sample Reinforcement.

“…This is not the first time that the lack of sample reward has been proposed to cause the OPE. Such a proposal was made some 4 decades ago and has been repeated by others in the interim (e.g., Carter & Werner, 1978;Delius, 1994). Strangely, since no one has previously tested this proposal, one can only guess that its common-sense appeal has kept it viable all these years.…”

Predicting Taxonomic and Thematic Relational Responding

“…Such an analysis would not necessarily fly in the face of established explanations for responding in matching to sample (Carter & Werner, 1978;Cumming & Berryman, 1965) for non human subjects in which responding in the conditional discrimination is controlled by stimulus rela-tions of the type if ... then (i.e., if Al, then Bi) and the conditional discrimination is thought to be composed of a successive discrimination (between samples) followed by a simultaneous discrimination (between comparisons), that is, is composed of two, threeterm contingencies (Sidman, 2000).…”

“…Lowenkron, 1998). A third possibility is that the stimulus control topography in this trial type is if ... then (Carter & Werner, 1978), that is, if Al, select Bl. In this last instance, the subject's comparison selections could be under the control of neither the identical physical features, nor the taxonomic relation exemplified by the stimuli, but only the if ... then relation established by the contingencies in a conditional discrimination.…”