Serial discrimination reversal learning in the pigeon: Potentiation of "pattern" by a conditional cue.

In 6 experiments 52 domestic pigeons were trained daily on a conditional serial discrimination reversal problem. In the standard training procedure, on odd-numbered days a vertical line was superimposed on a successive wavelength discrimination task. On even-numbered days a horizontal line was superimposed on the reverse wavelength discrimination task. Exps I, II, and III assessed the degree of control acquired by the compound conditional cues (lines plus "days") and by the component elements (lines or "days"). Only Ss trained with lines relevant mastered the reversal task. In testing, when the conditional line stimuli were present, they exerted strong control, and no day effect was noted. However, when tested in the absence of lines, Ss that had had training with the compound conditional cue demonstrated reversal performance controlled by day (i.e., the pattern of alternating reversals had been acquired). Exps IV, V, and VI tested alternate interpretations of the control exerted by the day cue. Results imply that the "potentiation" effect noted is due to separate storage of the wavelength discrimination problems and different retrieval processes elicited by presence vs absence of the line stimuli. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Paleostriatal lesions in the pigeon (Columba livia) potentiate classical conditioning: Evidence from fixed-interval responding, free operant go–no-go discrimination, and alternation.

Explored the existence of behavioral deficits in the paleostriatum augmentatum in 4 experiments in which pigeons were given bilateral electrolytic lesions. Exp I, conducted with 16 Ss, investigated the effects of lesions on keypecking for reinforcement on a 1-min FI schedule. The lesions increased total response rates, but response timing was not disrupted in paleostriatal Ss. In Exp II, 17 naive Ss were given VI baseline training and, in contrast to the results of Exp I, paleostriatal lesions did not increase responding. Go–no-go discrimination, which followed baseline training, revealed enhanced positive behavioral contrast in paleostriatal Ss, which was explained in terms of additivity theory. The results of Exps I and II suggest that potentiated classical conditioning occurred in paleostriatal Ss. In Exp III, 16 naive Ss were given spatial alternation training, and performance was temporarily impaired following paleostriatal lesions. The same paleostriatal Ss showed superior differentiation performance in Exp IV with a classical go–no-go alternation procedure (which also suggested potentiated classical conditioning). It is argued that disruption of (irrelevant) response-produced information may account for paleostriatal superiority. (55 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reactivation of a visual discrimination in early infancy.

16 78–92 day old infants learned to produce movement in 2 successively presented overhead crib mobiles by footkicking in a conjugate reinforcement paradigm. The mobiles differed in both color and pattern displays on the suspended components. Following acquisition, a discrimination was introduced whereby responding was reinforced in the presence of one mobile (the positive stimulus; S+) but not in the presence of the other (the negative stimulus; S–). During a cued-recall retention test administered 21 days after the completion of discrimination training, Ss evidenced no retention of either initial or discrimination training. Nevertheless, a brief reactivation treatment with S+ 24 hrs prior to the long-term retention test alleviated forgetting and restored the S+/S– discrimination. Reactivation with S– was no more effective than no reactivation treatment at all. Results confirm the efficacy of reminder procedures with young infants and demonstrate the specificity with which the reminder alleviates forgetting. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attenuation of reversal deficits of mice with septal lesions by shifts in the motivational context.

Response perseveration following septal lesions (SLs), demonstrated on tasks that require change of a learned pattern of responding, depends in part on a relatively constant motivational context. The present experiment examined the effects of concurrent changes in the temperature of the water in a water-escape maze and the reversal of a spatial discrimination in 83 male Binghamton heterogeneous mice that had received either SLs or control surgery. Control and experimental Ss were trained on a spatial discrimination in either 17 or 34°C water. Following acquisition, reversal training was conducted in the maze filled with the same temperature water used during acquisition, or both water temperature and spatial reinforcement contingencies were reversed. When the water temperature remained constant across acquisition and reversal, Ss with SLs showed persistence during reversal training. Changing the water temperature concurrently with the institution of reversal training attenuated the perseverative deficits of Ss with SLs, in contrast to the relative lack of effect in controls. The role of the septal region in attention is discussed. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Asymptotic free-operant discrimination reversal in the goldfish.

Studied 8 goldfish in a 7-stage experiment. The general pattern of asymptotic free-operant red-green discrimination reversal was the same whether the schedule of reinforcement for response to S+ was VI 1 min. or VI 2 min., whether 1 or 3 days of training per reversal were given, whether reversal occurred at the start of an experimental session or in midsession, and whether 1 or 2 stimuli were encountered in each session. Rate of response to S+ increased gradually from a low initial level, decreasing slightly in the intersession interval, while rate of response to S- decreased gradually from a high initial level, increasing slightly in the intersession interval. The pattern was also the same as that found in discrete-trial experiments with goldfish but different from that found both in free-operant and discrete-trial experiments with pigeons. Data are reported for control Ss treated like the experimental Ss in all respects except for the correlation between color and reinforcement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Operant responding for visual stimuli during sensory deprivation: Effect of meaningfulness.

Employed slide series differing in amount of meaningfulness as reinforcers for conjugately programed operant responding during 2-hr sessions of sensory deprivation and control conditions. Ss were 36 student nurses, 17-22 yr. old. Every S had the opportunity to respond to the slide series under both sets of conditions. Rates of responding under both conditions were higher for the more meaningful slide series, but rates of responding for the least meaningful reinforcers were higher under sensory deprivation conditions than under control conditions. Results are interpreted as indicating a need for nonmeaningful stimulation and for meaningful stimulation during sensory deprivation. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Helping counselor trainees learn to respond consistently to anger and depression.

50 graduate students were randomly divided into 5 groups that were exposed to different kinds of videotaped counselor training procedures. The group of main interest was exposed to a training procedure that enabled the Ss 1st to verbally practice responding to client negative affect and then to observe a model counselor's response. When these Ss counseled either angry or depressed role-playing clients, they responded more consistently to client feelings than did Ss exposed to other training procedures. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual discrimination and reversal learning in the aged monkey (Macaca mulatta).

Visual discrimination and reversal learning were assessed in young adult (10–12 yrs old, n?=?4) and aged (23–27 yrs old, n?=?5) female rhesus monkeys. Performance was comparable across age groups in many tasks, suggesting that the acquisition of stimulus–reward associations remains largely intact in the aged monkey. Most older Ss, however, required more training than any young animal to learn an initial pattern discrimination. In combination with previous findings (P. R. Rapp and D. G. Amaral; 1989) from the same groups of monkeys, these data suggest that deficits in attending to the relevant stimulus features in novel testing procedures may contribute to poor performance in aged Ss across a variety of learning and memory tasks. In addition, preliminary findings from a discrimination probe procedure raise the possibility that aged Ss may adopt alternate testing strategies that compensate for some aspects of age-dependent cognitive dysfunction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early experience in domestication.

Conducted 2 experiments to assess the ontogenetic as well as phylogenetic influences of early experience on domestication. A total of 40 Long-Evans hooded and 32 Sprague-Dawley albino domestic rats and 72 1st generation, laboratory-reared wild rats were the Ss. Exp I was a factorial, reciprocal cross-foster study. Exp II was a factorial assessment of the combined effects of preweaning handling and postweaning enriched environments. These experiments on rat domestication show that preweaning handling had a strong influence on the ontogenetic development of the S in terms of reduced emotionality. Handled wild Ss became much more like domestic Ss in their behavior. This finding for handling contrasted with minimal effects for cross-fostering and enriched environments. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the acquisition of dimensional stimulus control by the pigeon.

Trained 80 domestic pigeons to peck a white illuminated key for variable interval (VI) reinforcement. Ss were tested for angularity generalization following 0, 5, 10, or 20 min. of VI-reinforced exposure to a given line angle. For 40 Ss, the line angle was 90–; for the others, 30–. The 0-min Ss showed a systematic preference for 90–; however, 5 min. of training (with either SD value) produced nondifferential responding during generalization testing. Both 10 and 20 min. of training produced reliable gradients peaking at the SD values, with the 20-min gradient sharper but not reliably so. Furthermore, the 2 20-min gradients, peaking at 90– and 30–, were equal in slope. The various groups did not differ reliably in absolute level of responding during generalization testing, suggesting that response strength was fully established prior to the introduction of line training. Under this condition, dimensional stimulus control was acquired very rapidly and initial stimulus preferences were as rapidly overcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hippocampectomy disrupts the topography of conditioned nictitating membrane responses during reversal learning.

The effects of bilateral hippocampectomy on the topography of conditioned nictitating membrane (NM) responses in 24 male New Zealand white rabbits were examined during 4 learning tasks: 1-tone delay conditioning, unpaired extinction, 2-tone discrimination, and reversal of 2-tone discrimination. Results show that hippocampal ablation altered conditioned NM response topography only during reversal learning and not during the other training paradigms. The shapes of learning curves for hippocampectomized Ss were different from those of controls only during reversal conditioning. Implications for unit-recording studies of hippocampal cellular activity during classical conditioning of the NM response are discussed. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contextual control in discrimination reversal learning.

In 3 human predictive learning experiments, the authors examined contextual control of responding in discrimination reversal learning. In Phase 1, a discrimination between 2 stimuli (A+, B-) was trained in Context 1. During Phase 2, participants received discrimination reversal training (A-, B+) in Context 2. Testing occurred in Context 1 and Context 2 (Experiments 1A and 1B) or in Context 1 and Context 3 (Experiment 2). During the test phase, performance in Context 1 and Context 2 reflected the contingencies trained during Phase 1 and Phase 2, respectively. When testing occurred in Context 3, there was no discriminative responding between A and B. In addition, the experiments demonstrated that discriminating stimuli with a consistent reinforcement history were also affected by contextual manipulations. Results indicate that each training context acquires the ability to control performance. Unique-cue and configural approaches account for a major part of the results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus control after extradimensional training in pigeons: A comparison of response contingent and noncontingent training procedures.

In an experiment with a total of 32 White Carneaux pigeons, 2 groups of Ss for which reinforcement was procured by keypecking were given true discrimination (TD) or pseudodiscrimination (PD) training with different colors of the house light before they were taught to peck at a display of 3 vertical lines and tested on the line orientation continuum. 2 other groups were trained in the same way except that no response was required during discrimination training. Of the latter groups, the TD-trained Ss acquired the keypecking response (with autoshaping) more quickly than the PD-trained Ss. Their generalization gradients did not differ. Of the former groups, the TD-trained Ss produced a steeper generalization gradient than the PD-trained Ss. These results suggest that (a) general transfer effects are produced by TD and PD training and (b) differential stimulus control resulting from these procedures is mediated by the operation of response-produced cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences and residual effects of food deprivation in the satiated rat.

Following 100 days of food deprivation, during which 9 male and 9 female albino rats received acquisition and extinction training in a runway, and following 2 mo of ad lib feeding, Ss were given a reacquisition test under satiated conditions. Results indicate that females were significantly superior in running speed and frequency of food consumption during satiated reacquisition; while there was a large performance decrement in males following the drive shift, females performed at about the same level during satiation as during food deprivation. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Olfactory basis for the delayed onset of maternal behavior in virgin female rats: Experimental effects.

A previous study showed that intranasal zinc sulfate (ZnSO4) treatment shortens the latencies for the onset of maternal behavior in nonpregnant rats. The present study attempted to determine whether after recovery from the effects of ZnSO4 treatment, the latencies for maternal behavior increased. In Exp I, with 28 Charles River female rats, nonpregnant Ss were intranasally infused with ZnSO4 or air were left untreated and exposed to pups starting 48 hr later. Olfactory discrimination tests using chocolate bits were done simultaneously. The ZnSO4 treatment resulted in short latency maternal behavior (1.1 days) compared with latencies of control Ss (3.8 days), but neither group showed any loss of olfactory discrimination. 3 wks later, ZnSO4-treated Ss showed increased latencies for all but retrieving, while control groups showed decreased latencies for all maternal behaviors. In Exp II, with 13 nulliparous Charles River females, intranasal ZnSO4- and air-treated Ss were given olfactory discrimination tests under food deprivation, using chocolate bits and guinea pig pellets. Choice of guinea pig pellets was more severely affected than choice of chocolate bits, but recovery of the discriminations was complete in 4-5 days. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioning of relative frequency of sniffing by rabbits to odors.

Developed and evaluated an automated procedure for sniff detection in 4 experiments with 21 adult New Zealand white rabbits. The sniff was identified by a brief episode of increased respiratory rate, usually with a well-defined time of onset. It was detected against the background of respiratory activity in Ss simply, reliably, and noninvasively by statistical evaluation of digitized pneumograph records. The basal rate of exploratory sniffing was controlled by familiarization. Upon conditioning to olfactory cues, the rate of sniffing for CS+ increased sharply above the basal rate during the 1st trials and was maintained at high levels by continued reinforcement. During extinction with discrimination between olfactory cues, the rate for CS– fell sharply at first and then more slowly toward the basal rate. With pseudoconditioning, Ss responded to an unpaired odor after several sessions; the rates of response acquisition and extinction and the maintained level of responding were lower than with a paired odor in classical delayed conditioning, and the response was not discriminative in respect to another novel odor given during extinction. The sniff displayed a prominent sensory bias for olfactory cues. The relative frequencies of sniffing and respiratory slowing were measured as CRs by screening procedures with a small computer. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hippocampal response patterns during discriminative eyeblink/jaw movement conditioning in the rabbit.

Rabbits were given concurrent training in eyeblink (EB) and jaw movement (JM) conditioning in which 1 tone predicted an airpuff and another tone predicted water. After 10 days of discrimination training, the animals were given 10 days of reversal training. In the discrimination phase, acquisition of the 2 conditioned responses was not significantly different; however JM discrimination errors were much more frequent than were EB errors. In the reversal phase, correct performance on EB trials increased gradually, as was expected, whereas there was immediate behavioral reversal on JM trials. Differences in size and topography of dorsal CA1 multiple-unit responses reflected the ability of the hippocampus to discriminate between stimuli in trained animals, corresponding to the performance of the behavioral discrimination. During JM trials, the rhythmicity of the neural response was further modulated by the type of the prior trial, suggesting the coding of sequential events by the hippocampus. Thus, hippocampal conditioned activity can rapidly change its magnitude and pattern depending on the specific trial type during a concurrent EB/JM discrimination task and its reversal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Father absence in low-income Mexican-American families: Children's social adjustment and conceptual differentiation of sex role attributes.

Investigated the effects of paternal deprivation on 248 4th-grade Mexican-American students. Drawings of the human figure--1 male and 1 female--were obtained from each S, following the procedures of the Goodenough-Harris Drawing Test. Ss were also administered Raven's Coloured Progressive Matrices and the Bender Gestalt Test. Each S was rated on degree of personal adjustment by his/her classroom teacher on a 4-point scale, ranging from well adjusted, no problems in relating to others, to serious maladjustment. Results show that father-present Ss obtained significantly higher Goodenough-Harris scores than father-absent Ss on both the male and the female figures drawn. The female figures drawn by the father-absent Ss had significantly fewer feminine attributes than those drawn by father-present Ss. Whereas teachers found father-present males and females and father-absent females fairly well adjusted, father-absent males were found to show significantly more signs of social and emotional maladjustment than all the other 3 groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cue and response-choice acquisition and reversal after exposure to uncontrollable shock: Induction of response perseveration.

Evaluated the effects of inescapable shock in shock-motivated cue, response-choice (RC), and RC/positional Y-maze discrimination tasks. Ss were 253 male CD-1 mice. In the RC paradigm, Ss were required to turn in a predetermined direction to escape, whereas in the RC/positional task, Ss were required to enter the arm to the right of the start arm on any given trial. Although inescapable shock retarded escape performance, this was dependent on task difficulty and on the compatibility between response tendencies and the response requirement of the task. Irrespective of the task, exposure to inescapable shock did not influence accuracy of discrimination responding (acquisition or performance of a previously established discrimination). Likewise, discrimination reversal performance was unaffected by inescapable shock in either the cue or the RC paradigm. In contrast, acquisition of the RC/positional reversal was retarded by inescapable but not escapable shock. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociation of spatial discrimination deficits following frontal and parietal lesions in monkeys.

Gave 40 rhesus monkeys dorsolateral prefrontal, posterior parietal, or inferotemporal lesions. 4 additional Ss served as unoperated controls. Ss then received 2 forms of spatial discrimination training, based on body position ("egocentric" cues) and on the position of an external referent ("allocentric" cues), respectively. On the former, a place discrimination reversal, frontal Ss were impaired but not parietals. On the latter, a landmark discrimination reversal, parietal Ss were impaired but not frontals; this result was also obtained on a test involving distance discrimination without reversal. Finally, the inferotemporals but not the frontals or parietals were impaired on a nonspatial object discrimination reversal. Results suggest that the 2 modes of spatial orientation, egocentric and allocentric, are related to frontal and parietal mechanisms, respectively. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)