Disrupted patterns of consummatory behavior in rats with fornix transections

The feeding and drinking behavior was examined in male rats with fornix transections and sham-operated control rats. Total food and water consumption was recorded but supplemented by a pattern analysis of feeding and drinking behavior. The behavior of the rats was continuously monitored during four hour morning and afternoon sessions under ad lib access and during a two hour session following adaptation to a restricted access feeding schedule. Rats with fornix transections were more active and exhibited increased frequencies of rearing, eating and drinking. The increased meal frequency in rats with fornix transections was accompanied by decreased meal durations and a reduction in the length of intermeal intervals. Total food and water consumption was unaffected by fornix transection as were the duration of sleep bouts and the frequencies of grooming, sleeping and carrying shavings. Fornix transections also reduced food carrying and food hoarding but only under conditions of restricted food access. The results suggest that fornix transection does not alter major homeostatic regulatory mechanisms nor does it alter the components of feeding and drinking behavior. Fornix transection alters, instead, the organization of microregulatory feeding and drinking patterns.     

Sustained behavioral contrast in children

Children were exposed to a multiple schedule involving equal variable-interval schedules in each of two components and a multiple schedule involving a variable-interval schedule in one component and an extinction schedule in the other. Response rates were equal in both components when each involved a variable-interval schedule. Response rates differed in the two components of the multiple variable-interval extinction schedule. Response rates were higher in the variable-interval schedule when the accompanying schedule was extinction than when it was variable interval. The increase in response rate in the variable-interval component, simultaneous with the decrease in response rate in the extinction component, illustrated sustained behavioral contrast, and was the first evidence of this phenomenon in children.     

IMPROVED CURVEBALL HITTING THROUGH THE ENHANCEMENT OF VISUAL CUES

This study investigated the effectiveness of using visual cues to highlight the seams of baseballs to improve the hitting of curveballs. Five undergraduate varsity baseball team candidates served as subjects. Behavior change was assessed through an alternating treatments design involving unmarked balls and two treatment conditions that included baseballs with 1/4-in. and 1/8-in. orange stripes marking the seams of the baseballs. Results indicated that subjects hit a greater percentage of marked than unmarked balls. These results suggest that the addition of visual cues may be a significant and beneficial technique to enhance hitting performance. Further research is suggested regarding the training procedures, effect of feedback, rate of fading cues, generalization to live pitching, and generalization to other types of pitches.     

Sentencing severity with mock jurors: Predictive validity of three variable categories

Previous studies have identified three categories of variables which influence decisions of mock jurors: type of crime, defendant characteristics, and personal characteristics of jurors. This study manipulated the following variables towards the ends of assessing their influence on mock jurors' sentencing severity: premeditated vs. unpremeditated murder, black vs. white defendant, low SES vs. high SES defendant. Only defendant SES predicted sentencing severity: low SES defendants were assigned significantly longer sentences than high SES defendants. None of the measures of juror characteristics correlated with sentencing severity. Failure to replicate significant relationships with most of these variables and sentencing severity suggest that results of studies which manipulate only one variable dimension may overestimate the influence of these variable dimensions in mock jurors' decisions.     

Women in families: feminist therapy and family systems*

Current family therapy has as its basis the concept of the family as a system. Systems theory has developed a set of explanations that are frequently functional in nature; they are often applied as though they assume that within a system a common goal is worked towards as in biological systems. For example, the concept of homeostasis is used in much the same way as Cannon (1929) used it to describe the mechanisms of stability within biological systems such as body temperature regulation. Here all the components of the system co-operate to maintain body temperature within certain limits. This functional assumption of a common aim amongst components of a system to achieve balance should be compared with a pluralist systems analysis which does not assume such commonality of goals. For example, a pluralist analysis could highlight the conflict inherent amongst different subsystems when one subsystem has more power than the other. At a theoretical level it can be seen that family systems theory has restricted itself to a limited set of assumptions about the explanatory concepts it uses. An analysis of women's psychology which has emerged through the developments of feminist therapy can enrich the theory and practice of family therapists.     

Test of structural relationships within a proposed exercise and self-esteem model

This study tested structural relationships within a model proposed to explain the manner in which self-esteem changes are associated with exercise experiences. As initially assessed by self-efficacies (EFFs) specific to physical tasks within a training program, we postulated that competence can generalize to feelings of global self-esteem (SE) through an intervening construct of perceived physical competence (PC). Three measures of EFF and two each of PC and SE were administered to 145 people in their mid- to late adulthood. Confirmatory factor analysis examined orthogonal and oblique versions of three measurement models and identified three distinct but correlated factors, each assessed by its hypothesized indicators. Alternative structural equation models were specified and tested using both normal and nonnormal estimation procedures. The proposed model provided the most parsimonious fit and explained 29% of the variance in SE. Confirmation of its structural relationships provides preliminary validity for model use in examining the manner in which exercise experiences influence levels of self-perception.     

Temporal properties of responding during stimuli that precede response-independent food

Pigeons' keypecks were reinforced with grain on the average of once per minute by schedules that maintained low response rates and by schedules that maintained high response rates. During these schedules, a fixed-duration conditioned stimulus (CS) ranging from 7.5 to 120 sec in duration across conditions terminated with response-independent food. Response rates during the CS were inversely related to CS duration. The rates and the temporal patterns of responding during the shortest CS were similar whether the ongoing schedule maintained high response rates or low response rates. As CS duration increased, the rate and pattern of responding during the CS converged on the rate and pattern of responding maintained by the baseline schedule. These data indicate that changes in responding during stimuli that signal response-independent reinforcement are not homogeneous throughout the CS; that response measures, such as “suppression ratios”, which presume homogeneity may mislead us; and that conditioned suppression and conditioned enhancement may be better talked about in terms of species-specific approach and avoidance than in terms of emotional states.