The classification and integration of edges as critical to the perception of reflectance and illumination

A pattern of luminances equivalent to that of a traditional simultaneous lightness display (two equal gray squares, one on a white background and the other on an adjacent black background) was presented to observers under two conditions, and matches were obtained for both perceived reflectance and perceived illumination level of the squares and their backgrounds. In one condition, the edge dividing the two backgrounds was made to appear as the boundary between a white and a black surface, as in the traditional pattern. The squares then were perceived as almost the same shade of middle gray. In the other condition, a context was supplied that made the edge between the backgrounds appear as the boundary between two illumination levels, causing one square to appear black and the other white. These results were interpreted as a problem for local ratio theories, local edge theories, and lateral inhibition explanations of lightness constancy, but as support for the concepts of edge classification, edge integration, and the retinal image as a dual image.     

Two-part stimulus integration and specific reading disability.

29 dyslexics and 29 control children were presented with two halves of a black cross, one-half being presented at varying interstimulus intervals after the other half. Both dichoptic and binocular presentations were used and separation thresholds were at greater interstimulus intervals for the dichoptic condition. Dyslexics had thresholds at greater intervals than controls. These differences were significant and there was no significant interaction of group by dichoptic condition. The relative magnitudes of difference between dyslexics and controls were as previously reported by Stanley and Hall (1973) and support the notion that dyslexics have longer visual persistence than controls.     

Personality patterns of white,black, and Mexican-American patrolmen as measured by the Sixteen Personality Factor Questionnaire

The Sixteen Personality Factor Questionnaire was administered to 461 Los Angeles patrolmen to abtain a normative police profile. Multivariate analysis revealed that the average patrolman appeared brighter, more reserved, dominant, and tough-minded (p less than .001) than the average male. Comparisons were made for 29 black, 33 Mexican-American, and 399 white officers. Mexican-American officers emerged as more conservative and relaxed than whites, while black officers appeared more experimental, analytical, and group-oriented. A comparison with an idependent police sample revealed common traits of self-assurance and conservatism. Results were compared with a social workers' profile and discussed in relation to police officers' actual job activities and community needs.     

Effects of Job Redesign: A Field Experiment1

A telephone company project to redesign the job of directory assistance operator was: studied in order to determine the effects on workers of “job enrichment” programs. The change increased the amount of variety and the decisionmaking autonomy in the operator's job. However, no change in work motivation, job involvement, or growth need satisfaction occurred as a result of the changes; instead, the changes had a significant negative impact on interpersonal relationships. After the changes, the older employees reported less satisfaction with the quality of their interpersonal relationships, and those supervisors whose jobs were affected by the changes reported less job security and reduced interpersonal satisfaction. Implications of these findings for the theory of job redesign proposed by Hackman and Lawler (1971) are discussed.     

Peripheral and central components in variants of the Mueller-Lyer illusion

Illusion decrement with prolonged inspection was used as a technique to assess the relative amount of central component in seven variants of the Mueller-Lyer illusion. Results indicate that all of the variant forms share a common, central component, while the peripheral components, such as lateral inhibition, vary as a function of the presence of converging lines in the illusion configurations.     

An empirical taxonomy of visual illusions

A classification system for visual-geometric illusions, based upon the interrelationships between behavioral responses to various distortions was created. Forty-five illusion configurations were presented to 221 observers. Factor analysis revealed that there are five classes of illusions. A secondorder analysis revealed that visual distortions are ultimately reducible to two global types of distortions: illlusions of extent and illusions of shape or direction.     

Role of conditioned reinforcers in the initiation,maintenance and extinction of drug-seeking behavior

The development of a secondary reinforcer as a result of associating a neutral stimulus (buzzer) with intravenous (IV) doses of morphine was studied in rats. Secondary reinforcement developed in the absence of physical dependence and followed the association of the stimulus with either response-contingent or non-contingent injections of morphine. Strength of the conditioned reinforcer, measured in terms of responding on a lever for the stimulus plus infusion of saline solution, was proportional to the unit dosage of morphine employed in pairings of buzzer and drug. When extinction of the lever-press response for IV morphine was conducted (by substituting saline for morphine solution) in the absence of the conditioned reinforcing stimulus, it was seen later that the stimulus could still elicit lever responses, until it too had been present for a sufficient interval of non-reinforced responding. Similarly, extinction of the response for morphine by blocking its action with naloxone in the absence of the stimulus did not eliminate the conditioned reinforcement. Another study showed that a passive, subcutaneous (SC) dose of morphine served to maintain lever-pressing on a contingency of buzzer plus sahne infusion. Furthermore, the stimuli resulting from the presence of morphine (after a SC injection) were able to reinstate the lever-responding with only the buzzer-saline contingency when such responses had previously been extinguished. Moreover, it was shown thatd-amphetamine could restore responding under the same conditions, and that morphine could also do so for rats in which the primary reinforcer had beend-amphetamine. It is suggested that animal data such as these show that procedures designed for the elimination of human drug-taking behavior must take into account secondary reinforcers as well as the primary reinforcer(s).