Motor functions of the basal ganglia

Summary A study of movement disorders such as Parkinson's disease and Huntington's disease can provide an indication of the motor functions of the basal ganglia. Basal-ganglia diseases affect voluntary movement and can cause involuntary movement. Deficits are often manifested during the coordination of fine multi-joint movements (e. g., handwriting). The disturbances of motor control (e.g. akinesia, bradykinesia) caused by basal-ganglia disorders are illustrated. Data suggest that the basal ganglia play an important role in the automatic execution of serially ordered complex movements.     

Promotion and employee turnover: Critique,meta-analysis,and implications

Qualitative reviews of the withdrawal literature have reached inconsistent conclusions regarding the strength of the relationship between promotion and turnover. Several issues were addressed in this study which may account for these inconsistencies. First, we differentiate among three distinct operationalizations of promotion: (1) promotion satisfaction; (2) perceptions of promotional opportunity; and (3) actual promotion. We then conduct quantitative reviews using meta-analytic procedures on turnover and the three operationalizations of promotion. We found no significant relationships between promotion satisfaction and turnoveror between perceived promotional opportunities and turnover. However, a significant negative relationship was found between actual promotion and turnover. Theoretical implication of these findings are presented.     

Academic Gender Bias and Women's Behavioral Agency Self-Efficacy

The relationship between academic gender bias and female students' agentic self-efficacy expectations was examined. Agentic self-efficacy expectations was defined as an individual's beliefs about her ability to successfully engage in proactive educational and career facilitative behaviors. Participants included 67 full-time junior and senior undergraduate women enrolled in traditional, nontraditional, and gender-neutral majors. Results revealed that perceived academic gender bias was significantly predictive of agentic self-efficacy expectations, above and beyond the contributions of sex role attitudes, gender concentration of major, and race/ethnicity. Implications for women's career development and future research are discussed.     

The effects of situational performance constraints on intrinsic motivation and satisfaction: The role of perceived competence and self-determination

Situational performance constraints, task interest, and pay contingencies were manipulated in a laboratory study in order to investigate the cognitive mechanisms associated with the previously observed detrimental effects of constraints on affective task reactions. It was hypothesized that feelings of task competence and self-determination would account for both the direct and the interactive effects of constraints on motivation and satisfaction. The results of the study indicated that despite the fact that participants' performance was being constrained and they were aware of these constraints, the mere presence of the constraints alone failed to result in lower levels of satisfaction or motivation on a proofreading task. Post hoc analyses suggested that the constraints, in fact, led to negative affective task reactions when they also reduced participants' feelings of competence and self-determination. Interestingly, participants' generalized locus of control was associated with such effects. Internals tended to maintain stronger feelings of competence and self-determination than externals in the presence of constraints, thereby also maintaining greater motivation and satisfaction.     

CULTURAL VARIATION IN PROBABILISTIC THINKING: ALTERNATIVE WAYS OF DEALING WITH UNCERTAINTY*

This study reviews research on cultural differences in “probabilistic thinking” and presents some intra- and inter-cultural findings. Strong differences are shown to exist between people raised under Asian and British cultures on measures of this ability. These differences were found to out-weigh any influence of subculture, religion, occupation, arts/science orientation and sex. Generally, Asians were found to adopt a less finely differentiated view of uncertainty both numerically and verbally than did the British sample. Numerical probabilities assessed by the Asians were more extreme and less realistic than those assessed by the British sample. Possible antecedents of these differences are outlined, and cultural differences in probabilistic thinking are shown to be compatible with decriptions of cultural differences in business decision making. It is argued that there are qualitative cultural differences in ways of dealing with uncertainty.     

Functional Differences Between Upright and Rotated Images

In Experiment I subjects imaged an alphanumeric character either upright or upside-down, and triggered a test display character. Their task was to decide as quickly as possible whether the test character was NORMAL or MIRRORED. On 72% of the trials the test was at the orientation imaged. Reaction time (RT) was then about 200 ms longer in the upside-down image condition. This difference reduced with practice. On the remaining trials the orientation of the test character differed from that of the prepared image. For upright images RT increased monotonically with the angular difference in orientation between test and image. For upside-down images RT did not increase monotonically with angular difference as there was a wide dip around the upright. Further experiments suggested that upside-down images can be rotated, but at considerably slower rates than upright ones, and that the apparent rates of rotation for upside-down images are dependent upon the width of the sector tested. These results indicate that visual short-term memory (STM) and long-term memory (LTM) are distinct; that the process of mental rotation does not operate directly upon LTM; and that functionally, upright and rotated images may differ in important ways.     

Ecological interventions and the process of change for prevention: Wedding theory and research to implementation in real world settings

Considers a preventive intervention effort designed to modify the characteristics and regularities of the school environment so as to enhance the expectations conveyed to high risk students. Employing this case effort (Weinstein et al., 1991) as a base, several issues are highlighted that deserve greater attention in the design, implementation, assessment, and reporting of other preventively-focused social interventions. These issues include: (1) the degree of program implementation fidelity, (2) the impact a lack of attainment of program fidelity may have on arriving at erroneous evaluation conclusions about social programs, (3) the ways in which the theory and basic research employed in the program rationale is appropriate to and reflected in the program as designed, (4) issues of program potency and dosage, (5) the ways in which quantitative and qualitative evaluation data can enhance each other, and (6) the import of evaluability assessments of programs prior to moving to outcome evaluations. In addressing these issues, the importance of developmentally- and ecologically-informed program formulations is underscored. Finally, the critical role that program reports such as the Weinstein paper, with its careful discussion of both the process of implementation and outcome assessments, can play in the development of more effective prevention program implementation efforts is highlighted.