A cusp catastrophe: Hysteresis, bimodality, and inaccessibility in rabbit eyelid conditioning

Three properties of the cusp catastrophe: bimodality, inaccessibility, and hysteresis were evaluated in rabbit eyelid conditioning. Bimodality was evidenced by the fact that responding tended to occur at either very low or very high levels, and inaccessibility by the fact that intermediate levels of responding were rarely encountered. Hysteresis was demonstrated when: (a) levels of responding attained under a continuous schedule of reinforcement were largely maintained by a schedule which was too lean to promote conditioning by itself; and (b) levels of responding attained with a high intensity unconditional stimulus were largely maintained by a lower intensity unconditional stimulus which was too weak to promote conditioning in its own right. These results are consistent with the model of conditioning suggested by P. W. Frey and R. J. Sears (Psychological Review, 1978, 85, 321–340) which postulates response-mapping rules based on the cusp catastrophe.     

Differences in human ability to judge veracity from the audio medium

The few past studies in this topic area have consistently found that human subjects, as a group, are able to judge veracity better than chance; but no findings have been published relating individual differences to judgmental accuracy. Thus the present study was designed as a first step in filling this knowledge gap. To create a stimulus set of lies and truths, which listeners would later judge for veracity, a method was employed that generated 10 audio-tape recorded lies and 10 audio-tape recorded truths. Each of 100 subject-listeners judged each audio-tape for veracity, and also provided information on a set of personological variables. Listener, as a group, were significantly better than chance in accurately judging veracity (p < .001). In addition, a set of personological variables (social intelligence, field dependence/independence, number of siblings, TV viewing habits, and confidence in judgments) was identified that accounted for 22% of the variance in accuracy (p < .0002). It is acknowledged that these findings are tentative and will require replication before they can be regarded as reliable or valid.     

Sensitivity and responsivity measures for discrimination learning

The present report considers alternative measures of sensitivity and response bias for the discrimination learning paradigm. The classical signal detection measures, d′ and β, were compared with their nonparametric equivalents, A′ and B″, with theoretical measures derived from threshold theory and with empirical measures derived from the ROC graph. Differential rabbit eyelid conditioning data from three experiments were analyzed with these measures, and the results of these analyses were used along with other information to determine which measures of sensitivity and response bias are most useful for the analysis of discrimination learning data.     

Attributions of causality and reactions to uncontrollable outcomes

The experiment tested the hypothesis that the stress experienced by a person who is unable to control aversive stimulation is not a function of lack of control per se, but of the attribution of causality that (s)he makes for failure to exert control. Subjects were given a problem-solving task, and were told that they could prevent aversive noise bursts by correctly solving the problems. Subjects then received false feedback that they had done either well or poorly on the problems. In addition, failing subjects received information that led them to attribute their performance either to their own lack of ability or to situational factors (task difficulty). Subjects who attributed their failure to their own incompetence felt considerably more stress than subjects who made situational attributions. In fact, the latter subjects experienced no more stress than subjects who were successful in controlling the stimulation. Surprisingly, subjects whose attributions for performance led them to feel personally incompetent performed better than the remaining subjects both on problems administered in the same situation, and on problems administered in a new and different situation. The implications of the results for future helplessness studies and for the learned helplessness model were discussed.     

Subjective probabilities and moral judgments

The two experiments reported here examined the relationship between subjective probability estimates and moral judgments (credit and blame assignment, trait attributions, and behavior evaluations). Subjects read about situations that varied in outcome valence (moral or immoral); in addition, the nature of situational demands (Experiment 1) or behavior frequency (Experiment 2) was varied. In the first experiment, subjective probabilities were related to judgments of immoral behaviors (but not moral behaviors), whereas the situational demands only had an impact on judgments of moral behaviors. Experiment 2 included a wider range of behavioral situations, and the probability estimates and moral judgments were assessed independently. In contrast to the first experiment, subjective probabilities were related to trait and behavior ratings of both moral and immoral acts. Consistent with the first experiment, however, subjective probabilities predicted blame but not credit. Across both studies, the prior expectancies were more strongly related to evaluations of immoral acts than moral acts. Implications for understanding the determinants of judgments of moral and immoral acts are discussed.     

Self-serving bias in the attribution of responsibility: Cognitive versus motivational explanations

The purpose of this study is to compare the cognitive and motivational explanations of differences in the responsibility assigned to the victim of a crime. It has generally been found that the victim of a crime is assigned more responsibility for that crime by similar others if its consequences are severe. The motivational explanation for this finding is that subjects are threatened by the idea that a serious crime can happen by chance. The cognitive explanation is that serious crimes are rarer and subjects attribute more of the responsibility for rarer events to those who experience them. This study tested these two explanations by independently varying the severity and the likelihood of a crime and examining attributions of responsibility to its victim. The results of the study support the cognitive explanation. Similar others were found to attribute more responsibility for a crime to the victim when that crime was presented as rare, irrespective of whether its consequences were mild or severe. In addition, when likelihood was controlled experimentally no effect of severity upon attributions of responsibility was found. These results suggest that, within the context of attributions of responsibility to victims, patterns of attribution consistent with those predicted by theories suggesting motivational influences upon attribution may actually represent the operation of cognitive processes.     

Instrumental to Pavlovian transfer: Learning about response-reinforcer contingencies affects subsequent learning about stimulus-reinforcer contingencies

Two experiments examined the interaction between response-reinforcer (R-S) and stimulus-reinforcer (S-S) learning. In both experiments, three groups of rats were exposed to escapable, yoked inescapable, or no shocks. All groups were then exposed to either two or four sessions of truly random control (TRC) conditioning (Experiment 1) or to an excitatory conditioning procedure (Experiment 2) in which the shock US occurred with either moderate or low probability. Excitatory strength of the CS was assessed during extinction by a conditioned emotional response (CER) test. Inescapably shocked rats conditioned less than did their escapably shocked and nonshocked partners under all TRC conditions of Experiment 1, but only conditioned less than their partners in Experiment 2 when exposed to the moderate CS-US contingency for four sessions. These results provide a clear demonstration of transfer between instrumental training and Pavlovian excitatory conditioning and thus, support the influence of learning about R-S contingencies upon subsequent learning about S-S contingencies. Both a contextual blocking interpretation and an expansion of the learned helplessness theory were discussed as possible explanations of this transfer.     

Extinction after aversive conditioning: An associative or nonassociative process?

A series of three eyelid-conditioning experiments with rabbits examined the traditional extinction procedure in which the CS is presented in the absence of US presentations. The first study employed a savings test to demonstrate that the rate of reacquisition is faster after a conventional extinction procedure than after a procedure in which the CS and US have been unpaired. The second experiment indicated that this readiness to respond in reacquisition was related to a carry-over effect from the initial acquisition trials. The third study demonstrated that acquisition and reacquisition are similar when the US is maintained in extinction but not when it is omitted. These results imply that procedures which retain the US during extinction are more effective than the conventional CS-alone extinction procedure in eliminating or inhibiting the associative connection between the CS and the US.