A conditioned reinforcer maintained by temporal association with the termination of shock

Two experiments were conducted to determine whether a stimulus can be established as a positive conditioned reinforcer by associating it with the termination of shock, but without training the animal to make any response in its presence. In the first, six rats were conditioned to press a bar to terminate shock on a variable ratio schedule; white noise was then substituted as the immediate consequence, with the shock terminating 30 sec after the last press in its presence. It was found that the rate of pressing in the absence of noise depended on the contingency between the pressing and the noise. The second experiment sought to determine whether the difference in rates before and after the onset of the noise was due to the reinforcement of prior responding by the onset of the noise or to the suppression of subsequent responding by differential reinforcement of competing behavior. Six more rats were trained in the same manner, but with shock terminating 30 sec after the onset of the noise, regardless of what the animal did in its presence. Again the rate was higher before the onset of the noise, indicating that pressing was indeed maintained by the noise as a conditioned reinforcer.     

Childhood play and adolescent leisure preferences: Associations with gender typing and the presence of siblings

Childhood play and adolescent leisure preferences were solicited from a sample of 168 predominately white undergraduate students, who also completed the Bem Sex Role Inventory (BSRI; Bem, 1974) and provided ratings of the amount of time spent in play and leisure with same- and opposite-sex siblings. Higher Femininity (F) scores were found among those females who gave higher ratings of interaction with female siblings. The BSRI measures were also predicted by play and leisure preferences for strongly gender-stereotyped activities. Amount of interaction with same- and opposite-sex siblings was associated with activity preferences for both sexes. There was evidence of more sex-stereotyped preferences being given by those with same sex siblings and fewer by those with opposite sex siblings. The results are discussed in terms of the possible influences of siblings upon play and leisure preferences and the differing developmental pathways of male and female sex roles.     

Halving and doubling isometric force: Evidence for a decelerating psychophysical function consistent with an equilibrium-point model of motor control

Several previous investigations have measured accelerating psychophysical functions for perceived force with exponents of about 1.7. Two halving and doubling experiments presented here imply a psychophysical function for perceived force with an exponent between 0.6 and 0.8. That is, more than a doubling of force was needed to double the sensation, and similarly for halving. In the first experiment, subjects squeezed rigid instrumented cylinders between the thumb and first two fingers of each hand. They generated and released a reference force with one hand, and then squeezed the opposite hand to produce a sensation magnitude equal to, twice that, or half that of the reference. An analysis using a model that accounted for compression bias yielded average psychophysical functions with exponents of 0.58 and 0.59 (nondominant and dominant hands, respectively). The second experiment was an attempt to replicate earlier results and to reconcile them with the first experiment by using a paradigm duplicated from a previous study. Subjects in the second experiment made unilateral halving and doubling judgments of handgrip while squeezing a hand dynamometer. Again, the halving and doubling judgments yielded decelerating functions with exponents of 0.75 and 0.80 (nondominant and dominant hands, respectively). Even though the results of the first two experiments contradict earlier investigations, they can be explained by an equilibrium model of motor control assuming that subjects halve and double the central motor command rather than the sensation of force. The force is simply the result of the mechanical equilibrium established between the load and the compliant effector (the hand). The predicted relationship between the motor command judgments, the compliance of the hand, and the resultant forces was confirmed in a third experiment in which the mechanical compliance of the three-finger pinch was measured by using a pneumatic manipulandum to apply force perturbations in a “do-notintervene” paradigm. The measured compliance characteristic was accelerating, just as predicted by the model, in order to produce a decelerating psychophysical function for “perceived force.” In this experiment, then, judgments of perceived force appear to be judgments of the central motor command.     

Chaining and secondary reinforcement based on escape from shock

Three white rats were trained to press a bar while being shocked. This produced a white noise. After 30 sec they were allowed to terminate both the shock and the noise by nosing a pigeon key. Comparison of the rates of pressing before and after the onset of the noise indicated that the noise itself was the immediate reinforcing agent for pressing. Furthermore, control tests showed that pressing was maintained only if it produced the noise: either omission of the noise or elimination of the dependency of the noise on the occurrence of the response led to a gradual abolition of pressing. When automatic termination of the shock was substituted for the key nosing requirement, however, only the key nosing extinguished. This indicated that the effectiveness of the noise as a reinforcer did not depend on its status as a discriminative stimulus for some other form of operant behavior.     

Skill‐based versus effort‐based task difficulty: A task‐analysis approach to the role of specific emotions in motivating difficult actions

We make a distinction between primarily effort-based and skilled-based tasks and examine the correspondence between emotion and task. We reverse attribution theory results wherein failure to expend effort engenders regret and accomplishing tasks with skill engenders pride, and propose these emotions as antecedents to effort-based and skill-based behaviors. Specifically, pride (regret) produces higher self-efficacy, behavioral intentions and sign-ups when the task (CPR training) is portrayed as skill-intensive (effort-intensive) compared to effort-intensive (skill-intensive) or easy. Our research highlights the value of integrating an attributional analysis of tasks into an appraisal theory of emotions and suggests mechanisms that might underlie this relationship.