Recovery of the US representation over time during extinction

Four experiments used a conditioned suppression procedure in rats to explore changes in the US representation over time during the course of extinction. They employed two previously reported effects: reinstatement of responding to an extinguished CS by separate US presentation, and the erasure of that effect by interposed nonreinforcement of a second excitatory CS. These effects have been interpreted as enhancing and depressing the US representation, respectively. Experiment 1 found the erasing effect to decrease but still to remain substantial after over a 4-day period, suggesting a partial recovery with time of a deliberately depressed US representation. Experiment 2 implicated this change as a contributor to the phenomenon of spontaneous recovery by showing that recovery to be sensitive to erasure effects. Experiments 3 and 4 found evidence for an interaction between the state of the US representation and the amount of associative change which results from nonreinforcement of an excitatory CS. When the US representation was strong, either because of reinstatement or the passage of time, nonreinforcement of a CS was especially effective in producing associative change. When the US representation had been depressed by erasure, those nonreinforcements produced relatively less associative loss. Moreover, these effects upon associations were reasonably stable in the sense that they left asymptotic differences in the strength of associations after extinction. Together with previous findings, these results point to an important role for the US representation in the performance and learning which occurs during extinction.     

Some relations of general intelligence and selective attention

General intelligence may set structural feature limitations on three aspects of selective attention: direction, adjustability, and breadth. Amiable hypotheses considered are that subjects of varying intelligence may (1) have some partially fixed tendencies to look at different dimensions of stimuli, (2) have varying rates of adjusting their direction of attention, and (3) have varying upper limits on breadth of attention for tasks demanding it. Data, theory, and methods bearing on these hypotheses were reviewed from the domain of visual discrimination learning.     

The Adams and Reis observations revisited

This experiment was designed as a replication of the Adams and Reis (1971, 1974) experiments, which posited a direct relationship between frequency of stuttering and the number of “off-on” laryngeal adjustments during speech. Twenty adult stutterers read two prose passages equivalent in length, word length, and semantic content. The first passage contained a normal distribution of syllable-initial voiced and voiceless consonants whereas the second contained only voiced phonemes. The results demonstrated significantly greater stuttering during reading of the all-voiced passage (P?0.05). These results did not confirm the earlier observations of Adams and Reis and mitigate the hypothesized relationships between stuttering frequency and “off-on” laryngeal adjustments.     

Imaginative role-playing,need for achievement,and perceived outcome in relation to occupational status

Forty-four male and 44 female subjects, divided on the basis of their need for achievement scores, responded to three short verbal cues in which the central character was either male or female. The three cues (store clerk, social worker, and author) were chosen in order to maximize status differences and to minimize masculinity-femininity differences. In responding to each cue, subjects had to imagine themselves in each role. subjects rated each character on semantic differential scales to provide impressions of personality. Ratings were found to be a function of sex of the subject and need for achievement level, as well as status of the occupation. However, no significant effects were associated with the sex of the role.     

The usefulness of distinguishing between a defensive and a nondefensive external locus of control

The study's purpose was to determine whether a distinction can be made between individuals adopting an external locus of control as a defense and those adopting the orientation because it reflects their life experience. It was hypothesized that the two groups differ in the amount of personal responsibility they accept for task outcomes. Internals and externals were identified and then further designated as high or low in action taking. Among externals, a high action-taking score implied defensiveness. Subjects randomly received either success or failure feedback on a presumed task of interpersonal sensitivity. Defensive externals varied their causal attributions as a function of outcome, whereas nondefensive externals did not (p < .05). The distinction between defensive and nondefensive external control was thus supported.     

A general framework for the analysis of concept identification tasks

A general framework is presented for concept identification based on hypothesis-testing theory. It is a modification of the duoprocess theory presented by Chumbley (1972). It is shown how Markov models for various complex concept identification tasks may be derived from this framework and how such models may be analyzed by making use of probability generating functions. Two experiments are described. In experiment 1 three tasks were used: two simple tasks, where the subject either only had to select the relevant dimension in order to solve the problem or only had to learn a short list of paired-associates, and a more complex task, where both processes were needed to reach the solution. The results were in general favorable to the theory. Experiment 2 was designed to test the application of the theory to the four-choice concept problem. The predictions of the theory are compared to those of the subproblem learning theory of trabasso and Bower (1964), modified to include a ‘learning-on-errors’ assumption. The fit of the duoprocess theory was reasonably good and superior to that of the subproblem learning theory.