Concept learning by pigeons: Matching-to-sample with trial-unique video picture stimuli

Abstract

Pigeons were trained to match-to-sample with several new methodologies: a large number of stimuli, computer-drawn color picture stimuli, responses monitored by a computer touch screen, stimuli presented horizontally from the floor, and grain reinforcement delivered onto the picture stimuli. Following acquisition, matching-to-sample concept learning was assessed by transfer to novel stimuli on the first exposure to pairs of novel stimuli. One group (trial-unique), trained with 152 different pictures presented once daily, showed excellent transfer (80% correct). Transfer and baseline performances were equivalent, indicating that the matching-to-sample concept had been learned. A second group (2-stimulus), trained with only two different pictures, showed no evidence of transfer. These results are discussed in terms of the effect of numbers of exemplars on previous failures to find concept learning in pigeons, and the implications of the positive finding from this experiment on abstract concept learning and evolutionary cognitive development.Human cognitive behavior is characterized, in part, by our ability to abstract rules and form abstract concepts (Medin & Schaffer, 1978). Indeed, even our ability to effectively communicate with others depends upon this ability (Premack, 1978). One question that logically follows from discussions of human cognitive capabilities is: To what degree can animals form and learn concepts? Whether they can or not, bears upon one measure of how unique humans really are in the evolutionary hierarchy of cognitive abilities.The concepts, which are the focus of this article, are relational ones; they depend upon relations between pairs of items, for example, in situations in which subjects judge whether or not two items are identical (same) or nonidentical (different)-a same/different task-or ones in which they choose a comparison item to match a previously presented sample item-matching-to-sample. It is possible to learn a rule-based concept in these situations, so that any pair of items can be correctly judged. These relational concepts are to be contrasted to

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

“…Although previous studies have shown better than chance oddity transfer in pigeons (e.g., Lombardi, Fachinelli, & Delius, 1984), this article is the first example in the literature demonstrating that pigeons can fully learn an abstract concept of oddity, and one of the few examples of pigeons fully learning any abstract concept. Other examples would be pigeons fully learning the abstract concept of matching-to-sample with video cartoons presented from the chamber floor (Wright, 1997;Wright et al, 1988) and pigeons fully learning an abstract concept of same/different with digitized travel slides (Katz & Wright, in press). The present study showed that the OPE was a major contributing factor to acquisition for the oddity group without sample reward.…”

Unihemispheric memory in pigeons-knowledge, the left hemisphere is reluctant to share

“…It is highly unlikely that our animals had acquired a symmetry concept, since their level of performance when initially faced with the second or the third pair of patterns was not importantly superior to that at the beginning of the first pair. Additionally numerous studies could show that pigeons need a large number of exemplars until switching to a more abstract cognitive strategy [32] and are not as easily trained to categorize 'symmetry' as suspected previously [14]. However, the unexpected unilaterality of left hemispheric memory with a partial absence of interhemispheric transfer are not altered by the fact that the stimuli could in principle be grouped into a symmetric and an asymmetric group.…”

Concept Learning in Animals

“…These more recent experiments have shown that experience with several examples of same/different relations increases the tendency of pigeons and both old-and new-world monkeys to transfer that training to new stimuli (Katz, Wright, & Bachevalier, 2002;Wright et al, 1988;Wright, Rivera, Katz & Bachevalier, 2003). However, no such constraint or limitation of stimulus set size seems to hold for chimpanzees (Oden, Thompson, & Premack, 1988).…”

“…In recent years, studies of both birds and mammals have revealed even better evidence for the transfer of conceptual same/different discriminations (e.g., Blaisdell & Cook, 2005;Katz, Wright, & Bachevalier, 2002;Mercado, Killebrew, Pack, Macha, & Herman, 2000;Oden, Thompson & Premack, 1988;Pepperberg, 1987;Wright, Cook, Rivera, Sands, & Delius, 1988;see Wasserman, Young, &Cook, 2004 and for reviews). These more recent experiments have shown that experience with several examples of same/different relations increases the tendency of pigeons and both old-and new-world monkeys to transfer that training to new stimuli (Katz, Wright, & Bachevalier, 2002;Wright et al, 1988;Wright, Rivera, Katz & Bachevalier, 2003).…”