Rats learn to eat more to avoid hunger

Several recent experiments have provided evidence that the ingestion of a distinctive food by rats can be a learnt instrumental act as well as an associatively conditioned reaction. In the previous work, maintenance food was withheld for shorter and longer durations on different days following access to the training food. Extra eating before the longer fast was interpreted as avoidance of hunger. This interpretation was based on the evidence showing that extra eating as a result of classical conditioning comes from pairing food stimuli with the presence of little or no hunger because of repletion with energy nutrients. The theory that the extra eating arose from a response-depletion contingency was tested in the present experiment by training rats on only a long fast or only a short fast. Greater increase in intake was seen before the longer fast. The results also replicated previously seen cycles of increase, decrease, and renewed increase in putative deficit-avoidant eating over about three trials, indicating that the extra eating reduces the response-reinforcing hunger and that the consequent part-extinction restores reinforcement. The shape of the learning curve was consistent with these cycles occurring from the start of training, further supporting the view that the increase in food intake before a long delay in refeeding is hunger-reinforced instrumental behaviour.     

Speech in spinocerebellar ataxia

Spinocerebellar ataxias (SCAs) are a heterogeneous group of autosomal dominant cerebellar ataxias clinically characterized by progressive ataxia, dysarthria and a range of other concomitant neurological symptoms. Only a few studies include detailed characterization of speech symptoms in SCA. Speech symptoms in SCA resemble ataxic dysarthria but symptoms related to phonation may be more prominent. One study to date has shown an association between differences in speech and voice symptoms related to genotype. More studies of speech and voice phenotypes are motivated, to possibly aid in clinical diagnosis. In addition, instrumental speech analysis has been demonstrated to be a reliable measure that may be used to monitor disease progression or therapy outcomes in possible future pharmacological treatments.     

Mindfulness and integrative self‐knowledge: Relationships with health‐related variables

This study examined how mindfulness and integrative self‐knowledge were related to health‐related issues. Men in general population (n = 103) and coronary heart disease samples (n = 101) completed the Mindful Attention Awareness Scale, the Integrative Self‐knowledge Scale, the Type 2 subscale of the Interpersonal Reactions Inventory, the Perceived Stress Scale, and the Anxiety and Depression Scales. In both samples, there was a moderate positive correlation between mindfulness and integrative self‐knowledge and they were negatively correlated with all health‐related variables. However, only integrative self‐knowledge explained independent variance in health‐related variables. Specifically, in both samples, the relationship between mindfulness and health‐related variables was mediated by integrative self‐knowledge. Mindfulness and integrative self‐knowledge are related domains of self‐awareness that are associated with a range of health‐related variables. These relationships are robust across samples drawn from general population and patients with coronary heart disease. The finding that integrative self‐knowledge explained additional variance in the health‐related variables after the contribution of mindfulness had been accounted for suggests that reflective self‐awareness in integrative self‐knowledge may make a unique contribution to the explanation of individual differences in health variables.     

The general factor of personality: Substance or artefact?

While it is now widely recognized that a general factor (GFP) can be extracted from most personality data, this finding has been subject to numerous critiques: (1) that the GFP is an artefact due to socially desirable responding; (2) that it is factorially indeterminate; (3) that it can be more parsimoniously modelled using blended variables; (4) that it shows less genetic variance due to dominance than should be true of a fitness trait; (5) that it correlates more weakly with g than would be predicted from Life History theory; (6) that it cannot be recovered across personality inventories. We present new evidence and argument to show that each of these critiques is open to reasonable doubt.     

Identifying predictor variables of weight loss outcome: Implications for a stepped program and weight management

Abstract

Four variables were identified that predicted outcome for the minimal and moderate intensity weight control programs presented in sequence. Predictive models for pounds lost and percentage overweight lost were computed for both programs and follow-up and accounted for 33% to 62% of the variance. The predictor variable that contributed to the two programs and follow-up was success in losing weight previously. Greater rate of weight loss in the first five weeks contributed to the model for the minimal intensity program and for follow-up and total number of calories expended in nonroutine physical activity added to the model for the minimal intensity program. Marital dissatisfaction of subjects was a predictor for the moderate intensity program and follow-up. The findings have utility for a stepped program for weight and provide confirmation of variables noted as predictors in prior research. This study may help in the quest to identify consistent predictors of weight loss success.     

Factors Impacting on Career Choices of Technikon Students From Previously Disadvantaged High Schools

Career development is a socially constructed process involving complex interactions among different structures, forces, and systems all constituting spheres of influence. The purpose of this study was to investigate factors that influence career decisions. Eighty respondents (40 males and 40 females with mean age of 22 years) participated in the study. Results revealed that family variables of parental high expectations of children and appropriate communications within the family, as well as factors such as prestige statuses of some occupations, school curricular subjects, academic performance, teacher influences, and peer pressure had strong positive influences on career choices. Barriers to career choices identified included finance, lack of appropriate information, poor academic performance, and unsatisfactory career counseling services. Results suggest need for a better approach to career education in schools and counseling services that are adaptive to social, economic, and cultural contexts.     

Influence of school-level variables on aggression and associated attitudes of middle school students

This study sought to understand school-level influences on aggressive behavior and related social cognitive variables. Participants were 5106 middle school students participating in a violence prevention project. Predictors were school-level norms opposing aggression and favoring nonviolence, interpersonal climate (positive student–teacher relationships and positive student–student relationships), and school responsiveness to violence (awareness and reporting of violence and school safety problems). Outcomes were individual-level physical aggression, beliefs supporting aggression, and self-efficacy for nonviolent responses. School norms and both interpersonal climate variables had effects on all three outcomes in theorized directions. Only one of the responsiveness measures, awareness and reporting of violence, had theoretically consistent effects on all outcomes. The other, school safety problems, affected self-efficacy later in middle school. Evidence of gender moderation was generally consistent with greater influence of school-level factors on female adolescents. Discussion focuses on implications in light of previous research and intervention possibilities.     

Predicting Presidential Performance in the United States: Equation Replication on Recent Survey Results

Abstract

For more than 2 decades, researchers have tried to identify the variables that predict the overall performance of U.S. presidents. In 1986, there emerged a 6-variable prediction equation (D. K. Simonton, 1986c, 1987b) that has been replicated repeatedly. The predictors are years in office, war years, scandal, assassination, heroism in war, and intellectual brilliance. The author again replicated the equation on recent rankings of all presidents from George Washington through William Jefferson Clinton according to a survey of 719 experts (W. R. Ridings, Jr., & S. B. Mclver, 1997). The original 6-variable equation successfully predicted both the overall rankings as well as the 5 core components of the rankings (leadership qualities, accomplishment, political skill, appointments, character and integrity). The predictive value of the equation was illustrated for the presidencies of Ronald W. Reagan, George H. W. Bush, and Clinton.     

Mediation analysis and categorical variables: The final frontier

Many scholars are interested in understanding the process by which an independent variable affects a dependent variable, perhaps in part directly and perhaps in part indirectly, occurring through the activation of a mediator. Researchers are facile at testing for mediation when all the variables are continuous, but a definitive answer had been lacking heretofore as to how to analyze the data when the mediator or dependent variable is categorical. This paper describes the problems that arise as well as the potential solutions. In the end, a solution is recommended that is both optimal in its statistical qualities as well as practical and easily implemented: compute z_Mediation.