Functional differentiation within the neostriatum of the rat using electrical (blocking) stimulation during discrimination learning.

Sixteen rats, eight with bipolar electrodes implanted bilaterally in the anterodorsal head of the caudate-putamen and eight with similar electrodes in the posteroventral caudate-putamen, learned a spatial and a form discrimination task and their reversals while receiving "continuous" stimulation. Rats receiving stimulation to the anterodorsal caudate-putamen were imparied on spatial reversal learning compared with the posteroventral group. On form discrimination reversal the posteroventral group were impaired compared with the anterodorsal group. This dissociation is related to the particular cortical neostriatal projection system for the region stimulated and demonstrates a behavioral differentiation in rat neostriatum comparable with that observed in the monkey.     

Use of perceptually based apparatus to train adult women's performance on a Piagetian measure of the horizontality concept.

A segmented container called the V-box was designed to train adult subjects who fail a Piagetian type measure of the horizontality concept. The first segment appears round when viewed from straight an and virtually all adults were able to predict correctly howthe water line would appear when this segment was half filled with water. Partitions can be removed and the water allowed to fill up the entire container which has straight-line boundaries. On a pretest, 28 of 43 subjects failedto indicate the water line correctly on the container, when its straight-line characteristics were apparent. Of these 28, 18 were able to do so after being exposed gradually to the container's rounded segment and, step by step, to its elongated segments with straight-line boundaries. The difference in pre- to posttest change in performance between these 18 subjects and the 10 control subjects was significant.     

The stages of acquisition in stimulus fading

Pigeons were exposed to a stimulus fading procedure in which control of responding was transferred from red and black stimuli to lines of different angular orientation. After superimposing one line on the red stimulus and the other line on the black stimulus, the intensity of the lines was gradually increased and that of the red stimulus was gradually reduced. Probes consisting of red and line stimuli presented separately were used during the course of fading to assess control exerted by each element of the compound. As the lines were faded in, they did not acquire control of responding. As red was faded out, control of responding was acquired first by the lower intensity red stimuli in combination with the line stimulus, and finally by the angular orientation of the lines. Probes also determined the point at which the line stimuli, presented alone, would maintain a high degree of stimulus control. The results demonstrated that new stimuli in fading acquire dimensional control of responding in two sequential stages. Acquisition of stimulus control in fading was explained in terms of attenuation of stimulus blocking.     

Sex-related effects on clinicians' attributions of parental responsibility for child psychopathology

An attempt was made to reproduce and extend previously reported data suggesting the operation of sex-related bias in clinicians' attributions of parental involvement in children's psychopathologies. More and less sex-role traditional male and female family-oriented practitioners were shown contrived profiles in which a boy or girl was described as masculine or feminine role-deficient, and apportioned maternal versus paternal blame, treatment focus, adjunctive therapy need, and likelihood of sabotage. As in the previous study, mothers were implicated slightly more than fathers and also were viewed as requiring relatively greater therapeutic attention by female than by male clinicians. However, several earlier findings were not replicated. Overall, the results offer only marginal support for the notion of sex-related practitioner bias.     

Stimulus control of differential-reinforcement-of-low-rate responding

Five pigeons were given single-stimulus training on an 8-sec differential-reinforcement-of-low-rate schedule followed by steady-state generalization training using 12 wavelength stimuli. Three birds had a high percentage of reinforced responses on the training schedule and flat generalization gradients of total responses. The birds with fewer reinforced responses had much steeper generalization gradients. Generalization gradients plotted as a function of both stimulus wavelength and interresponse time showed that for most birds, stimulus control was restricted to responses with long interresponse times. Responses with very short interresponse times were not under stimulus control and there was some evidence of inhibitory control of short interresponse times. Interresponse-times-per-opportunity functions, plotted as a function of stimulus wavelength, showed that stimulus wavelength controlled the temporal distribution of responses, rather than the overall rate of response. The data indicate that the differential-reinforcement-of-low-rate schedule generates several response categories that are controlled in different ways by wavelength and time-correlated stimuli, and that averaging responses regardless of interresponse-time length obscures this control.     

Cardiovascular responses to avoidance conditioning in the dog: Effects of alpha adrenergic blockade

Laboratory dogs were trained to press a response panel to postpone shocks during daily one-hour avoidance conditioning periods. Each dog was also confined in the experimental environment for 5 hours prior to the avoidance periods. Blood pressure and heart rate were monitored continuously during these experiments from chronically indwelling arterial catheters. Extended training resulted in the emergence of a cardiovascular response pattern during the pre-avoidance interval characterized by gradual increases in blood pressure together with decreases in heart rate. Elevations in both blood pressure and heart rate were sustained during the avoidance periods. During sessions in which alpha adrenergic activity was suppressed by phenoxybenzamine, absolute levels of blond pressure were found to be lower than during control (non-drug) sessions, but a progressive rise in blood pressure continued to be observed during pre-avoidance. These results suggest that sustained cardiovascular responses during avoidance periods are associated with activation of the sympathetic nervous system, but that the gradual rise in blood pressure during pre-avoidance is due to other factors.     

Perceived orientation in depth from line-of-sight movement

Twelve college students viewed computer-generated displays of a cross comprised of two orthogonal dotted lines, and judged the apparent in-depth orientation of the horizontal arm by positioning a horizontal bar mounted on a rotary potentiometer. The vertical arm of the simulated cross was always in the observer’s frontal plane, but the randomly textured horizontal arm was in one of nine orientations relative to the line of sight. Each observer viewed displays in which the simulated cross was, alternately, (a) stationary, (b) approaching the viewer, and (c) stationary but expanding in size. The static texture density gradient in the horizontal arm of the simulated stationary cross mediated perceived orientation in depth. Further, when motion perspective was added to the detail perspective, the impression of depth was enhanced, with the greatest enhancement obtaining at the near viewing distance. When dynamic magnification was added to the detail perspective, the impression of depth was attenuated; this effect was interpreted as an illusory case of motion perspective.     

Psychosocial maturity and interpersonal attraction

Psychosocial maturity (PSM), assessed by scores on the Inventory of Psychosocial Development, was related to interpersonal behavior. In Experiment I PSM and proportion of attitude similarity was varied using Byrne's attraction paradigm in a between-subjects design. The personality variable failed to affect attraction. In Experiment II PSM and proportion of attitude similarity were manipulated in a within-subjects design. High PSM subjects rated the stranger significantly higher in attraction at high levels of similarity and significantly lower in attraction at low levels of similarity when compared to Low PSM individuals. The results were discussed in terms of design differences in personality research and potential mechanisms by which PSM affects attraction (self-esteem and/or competence).