PLE: A high-level multiprogramming language for psychology

This paper describes a software system called PLE that is designed to turn a Data General Corporation computer system into a sophisticated infinite-channel tachistoscope. We describe hardware and software characteristics of the PLE system and evaluate its performance in comparison to a typical tachistoscope. Additionally, we describe two example experiments that have been implemented in the PLE system.     

Extradimensional shift learning in pigeons: Positive and negative transfer produced by prior discrimination training

Four groups of pigeons were trained on a free operant successive discrimination between line-stimuli differing in orientation. The groups differed according to their previous treatment. Two groups had received true discrimination (TD) training with stimuli differing in colour and two groups had received pseudo-discrimination (PD) training. For one pair of groups the line-stimulus that was to become the positive stimulus in the transfer stage of the experiment was superimposed on both colours and in these the subjects given PD training learned the orientation discrimination more readily than those given TD training. In the other pair of groups TD animals learned more readily than PD. These results require us to modify current theories of attentional factors in transfer.     

Causal attributions of high and low achievement motivation college students for performance on examinations

College students high and low in test anxiety attributed their performance on each of four examinations in a course to ability, test difficulty, preparation, and luck. Individuals high and low in test anxiety typically evidence systematic predispositions to account for their achievement-related behavior in different terms. The present research substantially replicated these earlier (laboratory and Intellectual Achievement Responsibility Scale) findings in an actual achievement setting. In addition, however, the present findings differed from the earlier evidence in some important respects. Specifically, (a) high test-anxiety students' attributions for failure were far less self-deprecating than in the laboratory evidence, and (b) high test-anxiety students' attributions (for both success and failure) became more personally flattering, or comforting, as the semester progressed. Results were discussed in terms of the laboratory — field distinction and of the influence of a temporal, or time of measurement, factor, hitherto ignored in the causal attribution literature.This research was facilitated by a grant from the Research Council of the Graduate School, University of Missouri-Columbia, and the National Institute of Mental Health (1 R08 31910), both to the first author.     

The effects of intergroup comparison on the polarization of opinions

This study investigates the expression of attitudes by individuals within the context of groups. A link is made between two theoretical areas: that of intergroup relations and that of the effects of group interaction on the expression of opinions. It is argued that individuals in groups adopt more polarized attitudes to achieve a more positively distinct group identity, and to afford themselves identification with that group. Subjects individually expressed their opinion on an issue, while the salience of group membership was varied by evoking the identity of an alternative group which held opposed opinions on the issue. When their own group identity was more salient, subjects tended to express their opinions in a more polarized manner, and in a manner more in keeping with the presumed view of their group. Also, they attributed to the other group attitudes that were more polarized and more in keeping with their presumed view of the issue.     

Recognition memoryfor pictorial events

Subjects viewed sequences of slides depicting everyday events, and in later recognition tests, they correctly rejected distractors that were inconsistent with some invariant of the event but falsely accepted consistent distractors. J. J. Jenkins has accounted for the differential recognition of consistent and inconsistent slides of pictorial sequences in terms of fusion, the abstraction of an event from a series of temporally related items. The conditions under which event fusion was likely to occur were manipulated in three experiments: degree of ordering of the action-sequence slides, semantic vs. nonsemantic orienting tasks during acquisition, and duration of retention interval Recognition performance was generally more accurate under conditions of semantic processing, ordered acquisition sequences (for the semantic task), and shorter retention intervals. However, these variables did not affect differential recognition of consistent vs. inconsistent slides. A further experiment showed that the absence of an effect of disordering acquisition sequences on differential recognition could not be attributed to subjects’ reordering the disordered sequences in a way consistent with the original event. The data did not support the hypothesis that recognition performance was based on fusion of events depicted by temporally ordered slide sequences. It was suggested that memory for featural detail is a relevant factor in performance.     

Memory for objects and parts

Performance on whole comparisons of two whole objects was compared to that for partial comparisons of a whole object and a part. In particular, same-different comparisons were measured for sequential displays of two-dimensional line figures. The comparisons were analogous to those in the word priority paradigm (Johnson, 1975). The whole comparisons were found to be more accurate and faster than the partial comparisons. This whole advantage was also found for accuracy using a two-alternative forced-choice procedure. This effect was found for brief displays of a single object and for longer duration displays of two objects. It was also found for three different sets of line figures. In contrast, the whole advantage was not found for unconnected figures. These findings were interpreted in the context of hierarchical representations of objects and parts.     

Social influences on remembering: Intellectual,interpersonal and intergroup components

When people recall an event collaboratively we may expect the product to be influenced by the combined cognitive resources of the group, interpersonal acquaintance of the members, and social competition engendered by salient intergroup considerations. Using undergraduate students and serving police officers as subjects, a range of experimental conditions was established which varied on the three factors of cognitive resources of the participants (Cognitive Resources), interpersonal acquaintance of the participants (Interpersonal Acquaintance) and professional salience (Professional Salience) of the recall material. Participants answered a questionnaire concerning a police interrogation they had witnessed, and rated how much confidence they had in their answers. Multiple regression revealed statistically significant associations between (i) Cognitive Resources and number of correct answers, (ii) Interpersonal Acquaintance and confidence for implicational errors, and (iii) Professional Salience and (a) number of implicational errors and (b) confidence in confusional errors. The theoretical implications for our understanding of memory as a social process are discussed, and the practical implications for courtroom testimony briefly described.