Effect of punishment on human variable-interval performance

Three female human subjects pressed a button for monetary reinforcement in a range of variable-interval schedules specifying different frequencies of reinforcement. On alternate days, responding was also punished (by subtracting money) according to a variable-ratio 34 schedule. In the absence of punishment, rate of responding was an increasing negatively accelerated function of reinforcement frequency; the relationship between response rate and reinforcement frequency conformed to Herrnstein's equation. The effect of the punishment schedule was to suppress responding at all frequencies of reinforcement. This was reflected in a change in the values of both constants in Herrnstein's equation: the value of the theoretical maximum response-rate parameter was reduced, while the parameter describing the reinforcement frequency corresponding to the half-maximal response rate was increased.     

The effect of signaled reinforcement availability on concurrent performances in humans

During Phase I, three female human subjects pressed a button for monetary reinforcement in two-component concurrent variable-interval schedules. Five different reinforcement frequencies were used in component A, whereas the reinforcement frequency in component B was held constant. Absolute rates of responding conformed to equations proposed by Herrnstein to describe concurent performances, and the ratios of the response rates and the times spent in the two components conformed to the matching law. During Phase II, the availability of reinforcement in component A was signaled by the illumination of a lamp. This resulted in suppression of response rates in component A and elevation of response rates in component B, these changes being reflected in a distortion of the matching relationship which took the form of a bias in favor of component B.     

IMPROVING THE GENERALIZED MNEMONIC PERFORMANCE OF A DOWN'S SYNDROME CHILD1

A training program was conducted to improve the generalized mnemonic performance, or memory, of a Down's Syndrome child. Training was directed at digit-span performance with generalization from training determined by responses to untrained mnemonic performance probes. The digit-span items varied in length from three to five digits. Each length constituted an item class, with each class trained within the framework of a multiple-baseline design. Probes consisted of untrained digit-span items, grammatical sentences, nongrammatical sentences, and match-to-sample items. A training procedure, in which 15 items from each class varied continually from trial to trial and from day to day, resulted in the percentage of correct responses to both training and probe items increasing to levels substantially above baseline. The results demonstrate the effectiveness of the training procedure in improving the generalized mnemonic performance of a Down's Syndrome child.     

Quasi-statistical inference in rating behavior I. Preliminary investigations

Bem and Allen (1974) have suggested that trait consistency-ratings can function as a moderator variable, with regard to the cross-situational validity of trait position-ratings. The present study attempts to consider the relationship between these two types of self-ratings. A model of “man the quasi-statistician” was proposed which yields the predictions that (a) consistency-ratings will vary positively with the polarization-estimate from position-ratings and (b) the extent of correlation will be a function of the degree of polarization associated with a given class of trait.In two experiments, position-ratings and consistency-ratings were obtained over a series of dimensions. The predictions were confirmed in both studies. In addition, Experiment II provided evidence for a correspondence between intuitive and formal estimates of central tendency polarization, although this was not the case for dispersion. The results were discussed as bearing on the model and as relating to the findings of Bem and Allen (1974).     

Increased susceptibility of aphasics to a distractor task in the recall of verbal commands

The ability of 15 control, 15 nonaphasic brain-damaged, and 15 aphasic patients to carry out three-word commands on the Token Test was studied under three conditions: no delay, 20-sec unfilled delay, and 20-sec delay filled with a counting task. Only aphasics with mild to moderate comprehension deficit participated in the experiment and their scores in the no-delay condition were not inferior to those of the other two groups. The 20-sec unfilled delay did not bring about a decrement of the performance in any group, while all of them were impaired with 20-sec filled delay. The rate of forgetting was, however, significantly greater in aphasics than in patients without language disorders, even when the scores of the no-delay condition were introduced as covariates in the analysis of the filled-delay condition. The same result was obtained when, in a second experiment, 4 sec elapsed between the end of the command and the beginning of the counting activity. The increased susceptibility of aphasics to the disruptive effect of the distractor task is viewed as following a failure in organizing verbal information, a deficit that may contribute to lowering their comprehension level.     

A comparison of self-directed and therapist-directed practice for fear reduction

Various amounts of self-directed and therapist-directed practice were evaluated in reducing fear of snakes. The conditions included an exclusively self-directed condition, a predominantly self-directed condition, a predominantly therapist-directed condition, and an exclusively therapist-directed condition. All treatments resulted in reduced fear on behavioral and self-report measures. The predominantly therapist-directed subjects showed more improvement than subjects in the exclusively self-directed and predominantly self-directed conditions, but not more improvement than subjects in the exclusively therapist-directed condition.