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.     

Suicide survivors: psychotherapeutic implications of egocide.

Interviews with seven of ten known survivors of jumps from the Golden Gate Bridge and San Francisco-Oakland Bay Bridge revealed that all of them experienced transcendence and spiritual rebirth phenomena. The psychotherapeutic implications of these findings lie in helping depressed and suicidal individuals confront death in a symbolic and meaningful way. The issue is one of "egocide" (symbolic suicide) and aiding individuals in the rebirth process. In this way actual suicides can be prevented. When individuals experience partial "deaths" (like loss, failure, rejection, depression, suicidal states, or negative parts of their egos), there is opportunity for "rebirth" (positive transformation, creative change, growth, and significant spiritual reawakening). The therapeutic task is to help individuals differentiate between "ego death" and total death and to discover through the creative process of psychotherapy that overt suicide need not be a solution.     

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).     

Prior experience as a moderator of disaster impact on anxiety symptoms in older adults

As participants in a panel study, 234 older adults were interviewed before, as well as after, serious flooding occurred in southeastern Kentucky. Floods are not uncommon in this area, but these were more widespread than most, and resulted in both previously exposed and newly exposed subsamples of disaster victims. Flood impact was measured at both personal and community levels. With preflood symptoms controlled, there were modest flood effects on both trait anxiety and weather-specific distress in older adults without prior flood experience, but no flood effects in older adults who had been in floods before. Thus, the study provides support for the "inoculation hypothesis" and other conceptualizations that emphasize the advantage of being familiar or experienced with a stressor that is at hand. An implication is that "experienced" victims could be a valuable resource in prevention efforts.     

Application of model-selection criteria to some problems in multivariate analysis

A review of model-selection criteria is presented, with a view toward showing their similarities. It is suggested that some problems treated by sequences of hypothesis tests may be more expeditiously treated by the application of model-selection criteria. Consideration is given to application of model-selection criteria to some problems of multivariate analysis, especially the clustering of variables, factor analysis and, more generally, describing a complex of variables.     

In search of closure: subjective contour illusions, Gestalt completion tests, and implications

This study investigates the construct validity of perceptual closure tests (CTs), and isolates a common processing demand from the right-hemisphere. Sixty-seven patients with focal unilateral lesions (34 right side, 33 left side), and 80 control subjects participated. Multivariate analyses indicated that there was substantial age-related variance in all CTs, while sex was variably significant; CTs are not uniform in their discriminating ability, and hence factorially complex; and their specifically right hemisphere-sensitive dimension was subjective contour illusions, and interestingly unrelated to facial discrimination ability. The methodological and theoretical implications are discussed.     

The Composite-Stimulus Analysis and the Quantal Nature of Stimulus Control: Response and Incentive Factors

The Psychological Record -     

Computer-based interactive video systems

Computer-controlled interactive video instruction provides an instructional technique that overcomes many of the shortcomings of using the computer alone as an instructional device. Students who have used interactive video modules have been shown to better retain the material presented and to enjoy the course more than students not using the video modules.