Blocking of the response-reinforcer association: Additional evidence

Response rates maintained by free-operant schedules are sometimes reduced when a brief signal is interposed between the response and reinforcer. Early interpretations of this rate reduction were in terms of associative competition between the response and signal, analogous to blocking and overshadowing effects obtained in Pavlovian conditioning. But subsequent evidence has disputed this interpretation by showing that the signal enhances response rate in several circumstances. The present study attempted to define the conditions determining the different effects by investigating the role of signal location in the delay-of-reinforcement interval. When it occurred immediately after a response, response rate was enhanced. When it occurred at the end of the delay interval, immediately preceding the reinforcer, the signal decreased response rate. A similar decremental effect occurred when the signal occurred in the middle of the delay interval, contiguous with neither the response nor the reinforcer. Similar blocking effects occurred with a response acquisition procedure. The results demonstrate that blocking effects do indeed occur in instrumental conditioning but that the usual procedure of using signals immediately contingent on responding confounds such blocking effects with the competing effects of conditioned reinforcement/marking.     

Psychopathy,anxiety and malingering

Psychopathy is commonly measured as a low score on an Anxiety scale or as a high score on the MMPI Pd scale. The Pd scale, the Spielberger et al. Trait Anxiety scale and a short Achievement Motivation scale were administered to a random postal sample of 115 Australians. It was found that there was a high positive correlation between the Pd and Anxiety scales. This strongly supports Eysenck's theory that psychopaths are neurotic extraverts. A possible alternative explanation of the findings, however, is that the Pd scale may measure not psychopathy but malingering.     

Law,professional practice,and professional organizations: Where do we go from here?

The ethical dilemmas presented to the practicing school psychologist by the plethora of laws that dictate procedures, policies, and instrumentation are discussed. The function of professional organizations, both national and state, is described as (a) anticipating legislation, (b) developing political impact, (c) affecting existing laws, and (d) affecting proposed legislation. Coordination of efforts among various groups and development of political expertise is urged as a way to approach issues of concern to both psychologists and their clients.     

Masking,aftereffect, and illusion in visual perception of curvature

Masking, aftereffect, and illusion paradigms were used to establish the spatial selectivity of curvature detectors in human vision. Arcs with the same chord orientation mask each other maximally when they are identical in radius and direction of curvature. There is gradual reduction in masking over an extensive spatial range as arcs diverge in curvature. The transition from convexity to concavity does not produce discontinuity in the masking function. The extent to which a straight line appears curved also depends on the curvature of arcs shown previously (aftereffect) or at the same time (illusion). It is suggested that these effects could occur through selective adaptation of detectors responsive to either global curvature or the orientation of local straight-line approximations within an arc. Evidence is reviewed in support of the latter interpretation.     

The free-operant partial reinforcement effect: A discrimination analysis

Twelve continuously reinforced rats were extinguished in a modified operant chamber, with an S^D for goal-approach after each bar-press. Three groups of twelve rats each trained under FR 10 were extinguished with the S^D for goal-approach after every 6, 10, or 14-bar-presses, respectively. Results showed: (1) number of bar-presses to extinction was a direct function of the bar-press to S^D ratio during extinction, (2) number of food or goal-approaches was independent of both training and extinction conditions, and (3) prior to the breakdown in discrimination a revised response-unit hypothesis, based on a discrimination analysis of the effect of intermittent reinforcement, accurately predicted the number of bar-presses for each FR group.     

Criterion-referenced and norm-referenced assessment of minority group children

A variety of problems have been experienced with psychological assessment of minority children. Traditional norm-referenced measurement has repeatedly received criticism concerning cultural unfairness or bias. Responses to such accusations primarily have been in the form of new instrumentation aimed at attaining a culture fair assessment. Little response has been evident from a conceptual standpoint addressing the issues of purpose and use of test results Although many have turned to criterion-referenced measurement as an answer to the problems of norm-referenced evaluation, cultural bias is not necessarily avoided in this framework either. Issues of who determines criteria and what those criteria include must be addressed if criterion-referenced measurement is to meet adequately the challenge of multicultural evaluation.     

The disadvantaged as a social and professional phenomenon

Being culturally disadvantaged is a social condition which is created, managed, and maintained by both social and professional institutions. When institutions attempt to sustain societal norms by selecting certain attributes and calling them desirable, these institutions are relegating large segments of the population to a deviant status if it does not share these attributes. The “culturally disadvantaged” are such a group. This phenomenon not only results in differential perceptions and expectations, but also influences their self-evaluation, academic success, and career opportunities. The transformation of deviance into incompetency has also led to formally sanctioned methods of managing deviancy. Methods, such as compensatory education, ability grouping, and special class placement can be viewed as maintaining the position that the culturally disadvantaged are indeed deviant and incompetent.     

Absence of binocular interaction between spatial and color attributes of visual stimuli

The hypothesis that induction of the McCollough effect (spatially selective color aftereffects) entails adaptation of monocularly driven detectors tuned to both spatial and color attributes of the visual stimulus was examined in four experiments. The McCollough effect could not be generated by displaying contour information to one eye and color information to the other eye during inspection, even in the absence of binocular rivalry. Nor was it possible to induce depth-specific color aftereffects following an inspection period during which random-dot stereograms were viewed, with crossed and uncrossed disparity seen in different colored light. Masking and aftereffect in the perception of stereoscopic depth were also nonselective to color; in both cases, perceptual distortion was controlled by stereospatial variables but not by the color relationship between the inspection and test stimuli. The results suggest that binocularly driven spatial detectors in human vision are insensitive to wavelength.     

The preventive and therapeutic effects of two school mental health programs

In 30 classrooms randomly assigned to experimental conditions, effects on mothers' reports of behavior symptoms were compared for (a) a parent education program; (b) an in-school program of consultation, counseling, training, and referral; and (c) control classrooms. A sample of 426 families were followed for 30 months from the child's entry into third grade. A simple unweighted count of the number of symptoms reported in a home interview had adequate validity, good reliability, low reactivity, and intrinsic significance. Both programs had significant preventive and therapeutic effects on boys but not on girls. Effects were immediate in the upper middle class families, delayed in the lower class families.The larger study on which this article is based was initiated some years ago by Professor Glidewell and his colleagues, and represents a pioneering research effort in the field of community psychology. The present article was prepared by the authors in response to an invitation from the Editor to report important and still timely aspects of the original study that were not previously published in archival sources. We are grateful to Professor Glidewell and his colleagues for giving us this opportunity to make their findings more generally available to community psychology researchers.This work was supported by research grant M-592 from the National Institute of Mental Health, U.S. Public Health Service, and the St. Louis County Health Department.     

Teaching directional skills to preschool and kindergarten children

Studied a new device and training procedure for teaching the directional orientation and sentence tracking skills used in reading and writing western languages. Twelve preschool and 14 kindergarten children were randomly assigned to E and C groups. Between pre- and posttests, Es practiced for a total of 20 min. over a two-week period with an electronic device which flashed a correct signal only when S scribed left-to-right through successive sentences from top to bottom of the display. Any error in sequence extinguished the signal. Cs received only pre- and posttests. On test sentences prior to practice neither Es nor Cs were able to show where the sentences began or how they went from beginning to end. After using the device, Es tripled their orientation and tracking scores, while Cs not given access to the device did not improve (p < .002). Left-right and up-down directional confusion, often the subject of many hours of remedial training, were shown to be rapidly corrected in normal children by the use of a simple electronic device providing clear feedback distinguishing correct from incorrect responses. Implications for prereading instruction are discussed.