On interpretation of interactions

The principle focus of this paper is on interpretation of interactions that are obtained when response probability is used as a dependent variable. It is argued that results obtained with probability [or any dependent variable) are only interesting insofar as they reflect something about a corresponding theoretical component. It follows that the functional mapping of response probability [which is measured) onto the state of a theoretical component (which is inferred) must be somehow specified if conclusions are to be meaningful. Depending on the nature of such a mapping, various types of results, particularly results involving interactions, may or may not be interpretable.     

Comprehending compass directions

Two experiments investigated the processes by which compass directions are comprehended. In both experiments, the task was as follows. A compass direction (e.g., 210 deg) was visually presented. The subject drew a representation of the direction and then pressed a key. Reaction time from onset of the stimulus to the keypress was measured. The results suggested a model of direction comprehension involving two steps: first, computing the nearest cardinal direction to the target direction, and then “rotating” from the cardinal to the target direction. Rotation could be performed equally well clockwise or counterclockwise. Additionally, north-south. tended to be comprehended faster than east-west, confirming past results that have shown an advantage of up-down over left-right in discrimination tasks.     

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.     

Delayed monochromatic hue matches indicate characteristics of visual memory

Short-term memory for 16 monochromatic hues from 425 to 640 nm was measured after six delays from .1 to 24.3 sec by means of an iterative, momentary stimulus-matching technique. Small shifts were revealed in the remembered hue produced by certain wavelengths at some delays. These shifts did not follow trends consistent with a storage dependent on sensory pathway characteristics, perceptually unique hues, or semantic encoding but may reflect entropic effects in a storage that is remarkably unbiased. By indicating the discriminability of hues in memory, standard deviations of the delayed matches reveal other characteristics of what is stored: Their smooth, exponential growth questions the existence of "levels" and permits estimating the half-life of hue memory; their continued resemblance to the discrimination function for simultaneously perceived hues suggests that the stored activity; closely resembled the sensory response of color. The results also indicate how successive comparisons may be corrected in applied color work.     

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.