PERCEPTION OF PICTORIAL SPACE BY BUSHMEN*

A new test for measuring the ability to perceive pictorial depth was used with children of two remote Bushman populations (!Xu and Kxoe), as well as with a sample of adult Bushmen drawn from these populations and a sample of urban Zulu children. The results show that subjects of apparently little sophistication are capable of perceiving depth when confronted with a ‘geometric’ figure. They also show surprising inter-group differences which cannot be easily explained by differences of environmental experience.     

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.     

Autism and Accuracy in Adolescent Perceptions of Friends' Sexual Attitudes and Behavior

This study uses data from adolescents matched with data from their friends to examine whether reference group effects on adolescent sexuality should be thought of as operating through the sharing of norms or the modeling of behavior. We observe that perception of attitudes has such a trivial reality component and such a strong autistic component that it cannot serve as a mechanism of peer influence. Perception of sexual behavior has a reality component which is as large as its autistic component, and large enough to serve as a route of influence. We reach two conclusions: (1) Reference group effects on adolescent sexual behavior probably work through behavior modeling rather than through normative influence. (2) Studies which infer peer influence on sexual behavior using only perception of peers will arrive at erroneous conclusions.     

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.     

Preferences for Individual Video Games as a Function of Their Emotional Effects on Players

Video games vary in terms of the emotional states they elicit from players. These differences in emotional reactions, in turn, help account for differential preferences of individual games. The three independent dimensions of pleasure-displeasure, arousal-nonarousal, and dominance-submissiveness were used to assess emotional impacts of individual games. In addition, a preference measure was constructed to evaluate attraction toward, versus avoidance of, specific games. In Study One, a group of subjects provided data on emotional responses to 22 common arcade video games and a different group rated their preferences for the same games. The emotional impact of video games was highly unpleasant, moderately arousing, and moderately dominance-inducing; thus, the predominant emotional response to these games was aggression, anger, or hostility. I n Study Two, subjects visiting a video game arcade were recruited and assigned to play two games each and to report their reactions to each game immediately after playing the game. Results showed that greater feelings of pleasure, and separately of arousal, while playing video games resulted in higher preferences for the games and that greater dominance (significant only for males) also led to higher preferences. It may be beneficial, therefore, to experiment with more arousing and more dominance-inducing game designs which are not necessarily unpleasant or which definitely yield high pleasure.     

Superimposition of response-independent reinforcement

Studies that have superimposed response-independent reinforcement (or reinforcers scheduled by contingencies placed on the absence of responding) upon conventional response-dependent schedules are reviewed. In general, providing alternative sources of reinforcement reduced response rates below the levels observed when alternative reinforcement was absent. However, response-rate elevation was sometimes found, particularly when rates of superimposed response-independent reinforcement were low. Superimposition of schedules providing reinforcers contingent on the absence of responding usually produced more severe response-rate decrements than superimposition of response-independent reinforcement. A variant of Herrnstein's equation, which assumes that some of the alternative reinforcers function as if they were delivered by baseline response-dependent source of reinforcement, is in qualitative agreement with the overall body of results obtained, and can predict both increases and decreases in response rate as resulting from superimposed reinforcers.     

Behavioral contrast in fixed-interval components: effects of extinction-component duration.

Seven albino rats were exposed to a multiple schedule of reinforcement in which the two components (fixed interval and extinction) alternated such that a presentation of the extinction component followed each fixed-interval reinforcement. In baseline sessions, the duration of the extinction component was constant and always one-third of the fixed-interval value. Probe sessions contained a probe segment in which the duration of the extinction component was increased; the response rate in fixed-interval components during the probe segment was compared with the response rate in the segments preceding and following the probe. The effect of increasing the duration of the extinction component was studied under three values of fixed interval: 30 s, 120 s, and 18 s, in three successive conditions. Response rate within fixed intervals was a direct function of duration of the extinction component. Pausing at the beginning of the fixed interval decreased as extinction duration increased. These effects were larger and more consistent for the shorter fixed-interval values (18 s and 30 s). These results indicate a functional relation between relative component duration and responding. For the component providing more frequent reinforcement, this could be stated as an inverse relationship between relative component duration and response rate. This relation is similar to findings regarding the ratio of trial and intertrial duration in Pavlovian conditioning procedures, and suggests that behavioral contrast may be related to Pavlovian contingencies underlying the multiple schedule.