Sequence learning in pigeons was studied in asimultaneous chaining paradigm: all stimuli and the opportunity to respond to each stimulus were available simultaneously. In contrast to the traditionalsuccessive chaining paradigm, a simultaneous chaining paradigm provides no differential feedback following each response (except the last). Subjects were first trained to perform on sequences of two (AB), then three (ABC), and then four colors (ABCD). Performance greatly exceeded that predicted by models of random choice. Generalization to novel arrays of three and four colors was complete. After training with a four-color sequence, the subjects were tested with subsequences consisting of all possible combinations of two and three of the four training colors (e.g., BD, AD, BC, ACD, BCD, etc.). The successful completion of these subsequences showed that the organization of the original sequence did not entail overt pecks to successive elements of that sequence. That subjects can respond accurately on nonadjacent subsets is not readily explained by a chaining theory, or by any theory that assumes that responding to element n provides a cue for responding to element n+1. 相似文献
John Dunning's Tune in Yesterday: The Ultimate Encyclopedia of Old-Time Radio, 1925-1976 (Englewood Cliffs, N.J.: Prentice-Hall, 1976---$14.95 until January 1st, and then $17.95) Vincent Terrace's The Complete Encyclopedia of Television Programs, 1947-1976 (South Brunswick, N.J.: A.S. Barnes, 1976---$29.95, two volumes) 相似文献
Five groups of pigeons were studied in an auto-shaping procedure which programmed two types of trials represented by hues on the response key. Each signal was separated by a brief intertriai interval. Three groups were studied with a positive correlation between one of the signals and food (contingent groups). They differed with respect to the frequency with which the positive signal appeared. Two noncontingent groups were studied in which the correlation between the signals and food was eliminated by programming food with the same probability following either signal. One noncontingent group had a high density of reinforcement produced by adding reinforcement in the other signal, at the same rate as programmed in the positive signal for the contingent groups. The other noncontingent group experienced the same number of reinforcements in the session as the contingent group with the least frequent positive trial, but these reinforcements were distributed with equal probability across the signals. Birds in the contingent groups with intermediate or infrequent positive signals all acquired reliable pecking, with acquisition most rapid for the infrequent signal. Maintained responding covaried with the speed of acquisition. No birds in the noncontingent groups showed reliable responding. Birds in the contingent group with a frequent positive signal (approximately 3/4 of the session), also showed no reliable pecking. This result suggests that more than one noncontingent group is informative for assessing the role of differential reinforcement probability in the acquisition of auto-shaped keypecking. In particular, a noncontingent group which controls for the frequency of reinforced trials is an appropriate reference group.
Rats were exposed to an autoshaping procedure in which each lever-contact or leverpress delayed trial offset and, hence, food delivery. Yoked subjects received identical trial-food pairings as did delay subjects. This procedure was studied at two delay values (2.5 and 10.0 sec) in experimentally naive rats and those which had previously received 25 sessions of autoshaping. The delay procedure retarded the acquisition of autoshaped responding in naive subjects and reduced responding for experienced subjects. Yoked subjects responded at higher levels than did delay subjects throughout training. 相似文献
Food-deprived pigeons were given briei meals of grain following the presentation of a lignt on a response key. Pecking the key had no consequence Virtually all of the pigeons pecked the lignted key. The number of trials prior to the first peck varied inversely witn the value of the mean interval between light onsets. Trials to criterion was a negative power function of the value of the intertrial interval. The addition of a second stimulus, never followed by food, retarded the acquisition of the keypeck, particularly at short intertriai intervals. During steady state performance, the value of two measures of response strength, rate and probability of responding, increased as a function of the duration of the intertriai interval.
ROD SERUNG: THE DREAMS AND NIGHTMARES OF LIFE INTHE TWILIGHT ZONE by Joel Engel (Chicago: Contemporary Books, 1990—$18.95, ISBN 0-8092-4538-8,368 pp.) THE PIED PIPERS OF ROCK 'n ROLL: RADIO DEEJAYS OF THE 50s AND 60s by Wes Smith (Marietta, GA: Longstreet Press, 1989—$16.95, ISBN 0-929264-69-X, 300 pp.) GUNSMOKE.A COMPLETE HISTORY by SuzAnne Barabas and Gabor Barabas (Jefferson, NC: McFarland & Co., 1990—$45.00, ISBN 0-89950-418-3, 832 pp.) is just that—a detailed narrative and then episode guide to both the radio (1952-61) THE COMPLETE ACTORS TELEVISIONCREDITS, 1948-1988, VOLUME I: ACTORS by James Robert Parish and Vincent Terrace (Metuchen, NJ: Scarecrow Press, 1989—$59.50, ISBN 0-8108-2204-0, 560 pp.) THE CHILDREN'S HOUR: RADIO PROGRAMS FOR CHILDREN, 1929-1956 by Marilyn Lawrence Boemer (Metuchen, NJ: Scarecrow Press, 1989—$25.00, ISBN 0-8108-2270-9, 230 pp.) I REMEMBER TELEVISION: A MEMOIR by Ira Skutch (Metuchen, NJ: Scarecrow Press, 1989—$29.50, ISBN 0-8108-2271-7, 273 pp.) LIVE TELEVISION: THE GOLDEN AGEOF1946-1958 IN NEW YORK by Frank Sturcken (McFarland & Co., P.O. Box 611, Jefferson, NC 28640—$29.95, ISBN 0-89950-523-6, 178 pp.) 相似文献
The acquisition, maintenance, and extinction of autoshaped responding in pigeons were studied under partial and continuous reinforcement. Five values of probability of reinforcement, ranging from .1 to 1.0, were combined factorially with five values of intertrial interval ranging from 15 to 250 sec for different groups. The number of trials required before autoshaped responding emerged varied inversely with the duration of the intertriai interval and probability of reinforcment, but partial reinforcement did not increase the number of reinforcers before acquisition. During maintained training, partial reinforcement increased the overall rate of responding. A temporal gradient of accelerated responding over the trial duration emerged during maintenance training for partial reinforcement groups, and was evident for all groups in extinction. Partial reinforcement groups responded more than continuous reinforcement groups over an equivalent number of trials in extinction. However, this partial-reinforcment extinction effect disappeared when examined in terms of the omission of “expected” reinforcers. 相似文献
Pigeons were trained to recall an arbitrary sequence on a delayed matching-to-successive-samples (DMTSS) task. Sample items were presented successively and then displayed simultaneously. Subjects were required to respond to them in the order in which they appeared. In Experiment 1, pigeons responded correctly on 75% of the trials on a two-item DMTSS task but at a chance level of accuracy on a three-item task. In Experiment 2, pigeons who learned to produce a three-item sequence prior to DMTSS training mastered a three-item DMTSS task at a 75% level of accuracy. Control groups, trained initially with the same items on nonserial tasks, performed as poorly on a three-item DMTSS task as the naive subjects of Experiment 1. It was hypothesized that pigeons that first learned to produce a three-item list were able to recall three-item samples in DMTSS because they had learned to represent three-item sequences. 相似文献
