Performance of psychopaths on cognitive tasks related to frontal lobe function.

On the basis of their performance on several cognitive tasks, including the Wisconsin Card Sorting Test (WCST), the Necker Cube, and a sequential matching memory task (SMMT), E. E. Gorenstein (see record 1983-01261-001) concluded that psychopaths have specific deficits in cognitive processes associated with frontal-lobe functioning. However, it is argued that his diagnostic procedures were inadequate and his results confounded by group differences in age, education, general ability, and substance abuse. In the present study, the WCST, Necker Cube, and SMMT were administered to 46 male prison inmates divided into low-, medium-, and high-psychopathy groups on the basis of a 22-item checklist developed by the present author (see record 1982-02477-001). ANOVAs and ANCOVAs (with age, education, IQ, and substance use as covariates) failed to detect any group differences in task performance. Similar results were obtained when diagnoses were based on the Socialization scale of the California Psychological Inventory and the DSM-III criteria for antisocial personality disorder and when multiple criteria were used. Some general problems associated with attempts to explain psychopathy in terms of brain damage or dysfunction are discussed. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Male psychopaths and their criminal careers.

Cross-sectional and longitudinal analyses were used to examine the criminal histories of male psychopaths and nonpsychopaths. Dependent variables included time spent in prison and conviction rates during each 5-year period between the ages of 16–45 years. Both types of analysis indicated that the criminal activities of nonpsychopaths were relatively constant over the years, whereas those of psychopaths remained high until around age 40, after which they declined dramatically. Nevertheless, more than half of the subjects in each group still received at least one conviction after age 40. The results are consistent with clinical impressions that some psychopaths tend to "burn out" in middle age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental investigation of heat generation during the mixing of granular materials using an overhead stirrer

Bladed mixers are commonly used for processing granular materials, requiring significant mechanical energy for optimal blending. During this process, heat is generated due to dissipated mechanical energy within the granular medium. However, our understanding of heat generation mechanisms without external thermal loads is limited. This article investigates heat generation by monitoring temperature changes in granular beds mixed using an overhead stirrer. First-order kinetic equations are employed to extrapolate experimental data to a thermal equilibrium where heat generation and loss rates are balanced. Lead, steel, and glass particles are utilized under different operating conditions. Notably, metallic particles exhibit faster heating due to their lower heat capacity. Increasing rotation speed, fill ratio, and particle size result in greater temperature rises. Additionally, flat blades generate more heat compared to tilted blades. Through dimensional analysis, the experimental data are collapsed into linear curves that correlate system power consumption and granular bed temperature with operating conditions.