GENERALIZATION DURING ACQUISITION, EXTINCTION, AND TRANSFER OF MATCHING WITH AN ADJUSTABLE COMPARISON¹

Abstract

Three groups of pigeons were given conditional discrimination training in which the number of standard stimuli was varied across groups. In the presence of each standard, a pigeon adjusted the comparison stimulus on a second key until the two keys matched. A report of this match (response on the first key) was reinforced. Transfer of the matching performance was investigated by adding new standards to the ones already available. All pigeons were exposed to two extinction sessions after 155 sessions of training. Rapidity of acquisition was inversely related to the number of standards presented. Generalization gradients derived from the several comparison stimuli showed that all pigeons reached a high level of accuracy in the presence of at least one standard, and some pigeons did so in the presence of as many as four of the six standards. There was no evidence of a systematic effect of extinction upon overall accuracy, or the individual generalization gradients. When a new standard was added, a given pigeon's performance (in terms of responding to the comparisons) was similar to performance in the presence of one of the old standards. However, the pigeons did not show evidence of confusion among the comparisons.

Complex Learning and Information Processing by Pigeons: A Critical Analysis

“…The transfer tests just described constitute generalization tests using a single novel stimulus. A more complete generalization study has been reported by Cohen (1969). Stimuli were presented on only two keys.4 Comparison hues always appeared on the right key, and a single response on that key produced the next comparison.…”

Acquisition, extinction, and reacquisition of a conditional discrimination to avoid shock by goldfish

“…With pigeons, positive reinforcement, and an extinction procedure of turning off the food dispenser, response strength (comparable to TwR) decremented, but the accuracy of the conditional discrimination choice response remained intact (Cohen, 1969;Cumming et aI., 1967;Looney et aI., 1977;Lydersen & Cheney, 1973). In the present study, TwR remained intact but choice accuracy decremented.…”

“…Earlier studies, using pigeons, food reinforcement, and the traditional extinction procedure of turning off the food dispenser, have uniformly found substantial decrements in the strength of the keypeck response, but little if any decrement in the accuracy of the choice response (Cohen, 1969;Cumming, Berryman, Cohen, & Lanson, 1967;Looney, Cohen, Brady, & Cohen, 1977;Lydersen & Cheney, 1973). Clearly, an extinction procedure that does not cause the accuracy of the choice response to diminish would be inadequate for the present purposes.…”

A matching-to-sample procedure for the study of visual perception and concept formation in infrahumans: A test in the pigeon

“…The middl e panel (Pm) contained th e sample st imulus d isplay (Ss), and th e eight side panel s (PI -P, seq uent ially sta rting from th e left side and omitt ing Pm) con tained the co mpa riso n st imulus d isplay s (Sc)' A trian gular block ex tended o ut from t he middl e panel to discourage peckin g at th e samp le wind ow. Opp osit e the middle panel (Pm) , eq uidis tant from all the st imulus pan els, was the end more than two comparison stimuli ; the largest number of comparison stimuli reported is six, and that was on a sequential matching task (Cohen, 1969). The present stud y was conducted to determine whether or not pigeons were capable of performing on a simultaneous matching task with as many as eight comparison stimuli (three bits of information transmission per respon se) .…”