The representation of nonuniform motion: induced movement

Induced motion occurs when there is a misallocation of nonuniform motion. Theories of induced motion are reviewed with respect to the model for uniform motion recently proposed by Swanston, Wade, and Day. Theories based on single processes operating at one of the retinocentric, orbitocentric, egocentric, or geocentric levels are not able to account for all aspects of the phenomenon. It is therefore suggested that induced motion is a consequence of combining two different types of motion signals: one provides information by registering the motion with respect to the retina, orbit, and egocentre; the other provides information only on the relational motions between the pattern elements. Simple rules are given for defining a frame of reference for the relational motion process, which can result in a reallocation of the motion signals. It is proposed that the two signals in combination are weighted differentially, with the greater influence coming from the relational signals. Procedures for determining the weighting factors are described, and predictions from the model are examined.     

The perception of continuous curves in dot stimuli

Two categorisation experiments are reported in which the perceptual phenomenon that some simple arrays of discrete dots appear as a continuous curve whereas others are perceived as an angular contour or as consisting of separate groups of dots was investigated. Triplets of dots were presented in the first experiment, and complete or incomplete regular dot polygons (ie dots positioned on the vertices of imaginary regular polygons) in the second. In both experiments the perception of a curve versus an angle was determined mainly by the relative orientations of the dots, ie by the angles between successive virtual lines, whereas the lengths of the virtual lines had relatively little influence. In experiment 2 the number of displayed dots was shown to be a second independent factor for perceiving continuity. These results are in agreement with results from experiments on dipole textures discrimination, and suggest the psychological existence and importance of virtual lines in the visual processing of dot stimuli.     

Individual differences and measures of aggression in laboratory studies

After inducing hostility toward a confederate by threatening subjects' self-esteem, subjects were then given the opportunity either to deliver shocks (Experiment 1) or to withhold rewards (Experiment 2) from their confederate. Physiological measures were taken prior to the hostility induction, shortly after the induction and, finally, after the opportunity to aggress. Measures of individual differences relating to aggressive behavior were also considered. While the experimental manipulation was the best predictor in the ‘withholding rewards’ condition, measures of dissipation-rumination tendencies and emotional vulnerability were the best predictors in the ‘shock administration’ condition. In both conditions, systolic blood pressure seemed to reflect differences in arousal as a function of the hostility induction procedure, while subjects in the withhold rewards procedure also showed a decrease in systolic pressure after having an opportunity to aggress toward the confederate. It was concluded that not only is the withholding of rewards a more ethically acceptable procedure than shock administration, but it is also more likely to reflect experimental rather than individual difference affects.     

Auditory-visual interaction and the timing of inputs

Summary The objective of this study was to analyze the structural properties of the respective inputs that are conducive to immediate auditory-visual cross-modal bias. The study was designed as an updated and extended replication of one by Thomas (1941). Subjects were presented with either auditory or visual target signals in several positions around the median plane, together with a competing signal, always in the other modality, 15° to the left or to the right of that plane. The task was to indicate whether the target signal came left or right of center. Target and competing signals were delivered according to three temporal configurations: continuously on for 4 s, or periodically interrupted at either a fast or a slow tempo, and all combinations of the three configurations were used. Judgements of the location of the auditory target signal were attracted toward the visual competing signal in all conditions but two, those with a periodic target signal and a continuous competing one. Conditions with the two signals in the same configuration yielded larger biases than those combining different configurations, confirming that synchronization of discordant inputs is a major condition of cross-modal interactions. The occurrence of significant bias in nonsynchronous conditions, on the other hand, suggests that another factor might be the attraction of localization responses by competing signals with salient temporal configurations, and that interruption might be one important source of saliency. Auditory biases of visual localization were, as usual, smaller than visual biases, but nevertheless reached significance in a majority of conditions, and were also influenced by timing in much the same way as the latter.This work was supported in part by the Belgian Fonds de la Recherche Fondamentale Collective (FRFC) under convention 2.4505.80. The first author is Chercheur qualifié of the Fonds National de la Recherche Scientifique (FNRS). The results have already been reported at the Symposium on Perception, Action and Development, Brussels, January 1984     

Learning and motivation: Computer simulations of the Rescorla-Wagner,Solomon-Corbit,and Schull models

A suite of programs is described for simulating the Rescorla-Wagner (1972) model of associative learning, the Solomon and Corbit (1974) opponent-process theory, and Schull’s (1979) extension of the latter. The programs are written for the Commodore 64 computer.     

Biofeedback, cognitive training and relaxation techniques as multimodal adjunct therapy for hospitalized adolescents: a pilot study

Modifications and adjuncts to traditional therapy techniques appear to be necessary for successfully treating hospitalized adolescents with impaired social and verbal skills, and a history of acting-out behavior. Modified therapy groups were combined with a structured biofeedback and cognitive training program to help these adolescents control anger and modify their behavior. Used in conjunction with training and practice in relaxation techniques, this multimodal treatment approach appeared to be helpful in both reducing incidents of acting out on residential units, and in reaching individualized therapeutic goals. The present paper describes use of this multimodal approach within selected residential settings, and outlines the structured materials developed by the authors.     

Programming maintenance after correspondence training interventions with children

Interventions were employed to program maintenance following correspondence training. The use of reinforcement of verbalization and a mixed sequence of procedures designed to establish indiscriminable contingencies was evaluated in multiple-baseline designs across subjects and behaviors. The results indicated that target behaviors were maintained under less intrusive interventions and in the absence of programmed contingencies during extended follow-up conditions. The results are discussed in terms of changes in reinforcement schedules established in maintenance interventions.     

Reactions to Patients' Self-or Chance-Blaming Attributions for Illnesses Having Varying Life-style Involvement

The effects of the perceived accuracy of attributions of self blame and chance blame were examined in the context of health care. Health practitioners ( N = 147) rated interviews in which patients made self-or chance-blaming attributions for diseases with high (heart attack, stroke), or low (cancer, arthritis) life-style involvement, or acidental injuries. Three discriminant analyses yielded p < .001. Self-blaming heart and stroke patients were rated as coping better and acting more appropriately and typically than chance blamers. Other self blamers were rated as more depressed, poorly adjusted, coping poorly, not accepting disability, needing counselling and information. Additionally, self-blaming accident victims were judged as more dependent, less likeable, and having poorer prognoses than chance blamers. Realistic self blame for life-style diseases did not lead to victimization, but other self-blaming patients were stigmatized and the adaptiveness of self blame as a coping strategy was unrecognized.