Mediators of the effects of magnitude of reinforcement

The characteristics of mediational mechanisms based upon magnitude of reinforcement were investigated using rats. In two experiments, two-choice discriminations were trained in which selections of one lever in one external stimulus and a second lever in another external stimulus were reinforced with food. In the first experiment, it was found that the discrimination was acquired more rapidly when one choice was reinforced with a large number of food pellets and the other with a smaller number of pellets than when other configurations of reinforcement magnitude were provided. In the second experiment, reversal of a two-choice discrimination was found to be facilitated by prior exposure of the animals to the reversed relationships between the external stimuli and magnitudes of reinforcement. These results were consistent with predictions from a stimulus or associative view of anticipatory processes based upon magnitude of reinforcement.     

The effectiveness of visual and gustatory conditioned stimuli in human classical aversive conditioning with electric shock

Thirty-six undergraduate volunteers, divided into three equal groups, were given electric shock while sipping a colored, unflavored solution (Group I): a flavored, colorless solution (Group 2); or a colored, flavored solution (Group 3), in order to determine whether human Ss respond differentially to visual and gustatory cues when the UCS is aversive electric shock. Using a standard classical discrimination procedure, the CS + was blue water for Group 1, citric acid solution for Group 2, and blue citric acid solution for Group 3. For all groups the CS- was plain water, which was never paired with electric shock. The dependent variables were derived from Staats' A-R-D theory: attitudinal change (A) and a performance measure of sip-size taken during conditioning trials (D) both confirmed the hypothesis that taste can be an effective CS when the UCS is shock, in contrast to results typically obtained with rats where visual but not taste cues are effective with a shock UCS.     

The effects of perceived similarity upon the use of reward and punishment

Subjects were led to perceive a trainee as either similar or dissimilar to themselves. During subsequent influence trials, subjects attempted to assess the causes of the trainee's performance and to employ rewards, punishments, or manipulations of the trainee's environment to optimize her performance. It was predicted that subjects would perceive the performance of dissimilar trainees as caused more by the dispositional factor of motivation than the performance of similar trainees, and that dissimilar trainees would thus be rewarded more upon success as well as punished more upon failure. The hypotheses were supported, and a model of reward-punishment behavior and attribution is discussed.     

The effect of training procedures on the overlearning reversal effect in young children

The performance of 80 preschool children on a reversal problem was studied as a function of amount of training and type of training procedure used during acquisition and reversal. In the extinction phase of reversal learning, subjects given a correction procedure during the reversal problem made fewer perseverative errors than subjects given noncorrection. In the reversal midplateau phase of reversal learning, overtraining facilitated reversal learning for subjects receiving noncorrection during the acquistion problem, but not for subjects receiving correction. A shift in training procedure between acquisition and reversal increased the number of subjects who reached criterion immediately after perseveration. Since these results are difficult to explain in terms of traditional learning theories, an alternative response-switching strategy explanation was proposed.     

Partial reinforcement effects and type of reward

In two experiments 68 rats were trained to bar press or run down a straight runway for food or for water under conditions of either continuous reinforcement or partial reinforcement. In both experiments, there was greater persistence of behavior which had been reinforced with food than with water. In Expt 2, the partial reinforcement extinction effect (PREE) was observed with food reward, but not with water.Within the context of the experimental procedures used, it can be concluded that the rat has mechanisms for developing persistence which are dependent on the specific motivational system involved. This conclusion is related to theories of partial reinforcement effects and to possible biological origins of the mechanisms.     

The effects of uncontrollable failure and depression on memorial processes

Many investigators have argued that exposure to uncontrollable failure and depressed mood affect learning processes. However, little has been done to explore how information processing is affected by such events. Two experiments revealed that prior failure (Experiment 1) and depressed mood (Experiment 2) have similar effects on a simple free-recall task. These data are interpreted to suggest that the experience of uncontrollable failure and depression disrupt the transfer or retrieval of new information from a transient to a more permanent storage format. The implications of these data are discussed.     

Generality of persistence: The role of stimulus and response factors in persistence to punishment

Previous research has shown that intermittent punishment of a response increases its persistence to continuous punishment and that intermittent punishment training in one situation produces persistence to continuous punishment in other situations. Experiment 1 showed that as long as the instrumental response and punishing stimulus were held constant from intermittent to continuous punishment marked differences between these situations had no decremental effect on persistence. Experiment 2 showed that intermittent punishment training of one response resulted in substantial persistence to continuous punishment of a different and apparently incompatible response and that such response change had no more than a marginal effect on persistence. The results were seen as requiring some revision to the traditional conditioning-model interpretation of persistence to punishment.     

Peripheral vision: The effects of developmental,perceptual, and cognitive factors

The effects of perceptual and cognitive factors on information processing in the visual periphery were studied in 5- and 8-year-old children and in adults. Subjects judged either the similarity (Study 1) or the identity (Study 2) of geometric forms. In both studies, two forms were simultaneously presented for 20 msec at 2, 4, or 6°, with one form on either side of the fovea. Type of form and Axis of presentation were varied. Both studies demonstrated declining performance with increasing distance, poorer performance with open than closed forms, poorest performance along the vertical axis, and no major interaction of these factors with age. Greater “flattening” of the visual field was found in Study 2 than in Study 1 for all age groups. The results indicate that the parafoveal visual field is elliptical and that more difficult tasks accentuate this asymmetry. This effect of task demands on the relative flatness of the effective visual field cannot be interpreted on the basis of anatomical factors. The findings indicated striking developmental similarity in the effect of several variables on parafoveal processing and challenge the idea of greater tunnel vision in preschoolers than in adults. Further, the data suggest that perceptual and cognitive factors influence the size and shape of the effective visual field across the full age range studied.     

Age differences in organization and recall: The effects of training in categorization

An alternating sort/recall task was employed to train fourth graders and college students in organizational strategies. Free-sorting Ss, at both age levels, sorted a group of words into two to seven categories. Analyses of final sorting patterns indicated reliable differences between the children and adults. The organizational schemes thus developed by the free-sorting Ss were taught, by means of a yoking procedure, to other Ss. Results indicated that the recall of fourth graders was improved when they were forced to learn the sorting patterns developed by the older Ss. Similarly, impairment in the recall of college students was observed when they were required to sort according to the organization employed by the fourth graders. These findings imply that changes in organization can result in changes in recall performance.     

Partial reward training level and reward magnitude: Effects on acquisition and extinction

Two groups of 10 rats each received either a large magnitude (0.90 g) or a small magnitude (0.18 g) of partial reward (PR) and seven successive acquisition-extinction sessions in the runway. The large magnitude PR group ran much faster than the small magnitude PR group in the early acquisition sessions with differences between the groups declining over sessions. In the early extinction sessions, the large magnitude PR group showed greater resistance to extinction than the small magnitude PR group, but in the late extinction sessions this relation reversed itself. Finally, resistance to extinction decreased over sessions, this decrease being greater under a large than under a small magnitude of PR.     

The effects of positive and negative feedback and reward on originality

Forty subjects participated in a remote associates verbal learning task. Subjects were assigned to reward or feedback and positive or negative conditions in a 2 × 2 factorial design. Subjects in the various groups performed at significantly different levels with the positive reward group producing the most remote associates, folllowed, respectively, by the negative feedback, negative reward, and positive feedback groups. It was suggested that rewarding remote assocites results in relatively flat associative gradients, wherein the subject has ready access to all associates. Conversely, punishing common associates produces emotionality which reduces the response probability of remote associates, thus producing a relatively steep associative gradient. Extrapolations to Mednick's theory of creativity were made, suggesting that creativity is under environmental control.