Comparison of K-ABC performance between at-risk and normal preschool children

This study examined differences in K-ABC performance between at-risk (n = 44) and normal (n = 49) preschool children. For the group at-risk, all of the mean global scores on the K-ABC clustered around a standard score of approximately 90. The normal group's mean scores were 15 to 21 standard-score points higher and clustered near 110. The results of t tests for independent samples indicated that the normal group's scores on both the global scales and K-ABC subtests were significantly higher than the at-risk group's scores in nearly every instance. Correlations among scores were consistent with previous findings for preschoolers on the K-ABC. For the normal group, correlations obtained among the global scales were nearly identical to those reported for the standardization sample. For the at-risk group, however, the correlation of .75 between Sequential processing and Achievement was higher than that (.58) between Simultaneous processing and Achievement.     

DOES CONTINGENT REINFORCEMENT STRENGTHEN OPERANT BEHAVIOR?

In Experiment 1, pigeons were trained to peck keys with equal food-reinforcement schedules in components that ended with either noncontingent or contingent transitions to a third component with a five-fold richer schedule. Response rates were higher in the initial component with contingent transitions, but resistance to prefeeding or extinction was not consistently greater. Experiment 2 also included noncontingent or contingent transitions to a signaled period of nonreinforcement. There was no effect of the contingency on transitions to nonreinforcement, but the difference in response rates maintained by contingent versus noncontingent transitions to the richer schedule was replicated. In addition, response rates were higher in components that preceded nonreinforcement than in components that preceded the richer schedule. However, resistance to extinction was greater for noncontingent transitions to the richer schedule than to nonreinforcement, implicating stimulus–reinforcer relations in the determination of resistance to change. Resistance to change was also somewhat greater for noncontingent than for contingent transitions to the richer schedule. The latter result, together with the results of Experiment 1 and related research, suggests that response-contingent reinforcement does not increase resistance to change.     

Acute neuropsychological consequences of coronary artery bypass surgery

This study examines a series of coronary artery bypass patients (CABS) for neuropsychological and regional cerebral blood flow (RCBF) changes at 8 days and 8 weeks post surgery. Seventy-three percent were found to have moderate or severe neuropsychological deficits at 8 days post operation and 37% at 8 weeks post surgery. A comparison group of major vascular and thoracic surgery patients was also found to have a significant proportion of neuropsychological deficit following surgery. The RCBF assessments indicated a significant drop in mean RCBF at 8 days post surgery in the coronary artery bypass group which did not persist to 8 weeks. The comparison group showed no changes in RCBF following surgery. The findings suggest different patterns of recovery and origins of the neuropsychological deficit in the two groups and emphasize the need for appropriate control groups in studies examining the cortical effects of extracorporeal circulation. In addition, the project received generous support from the special trustees of the Middlesex Hospital.     

Perceived control and health

Perceived control (PC) is defined as thebelief that one can determine one’s own internal states and behavior, influence one’s environment, and/or bring about desired outcomes. Two important dimensions of PC are delineated: (1) whether the object of control is located in the past or the future and (2) whether the object of control is over outcome, behavior, or process. A variety of constructs and measures of PC (e.g., efficacy, attribution, and locus of control) are discussed in relation to these dimensions and selected studies are reviewed. The issues, controversies, and limits of the research on perceived control and health are addressed in terms of the antecedents and consequences of perceived control. Investigations should clearly conceptualize the object of perceived control, use measures that match the conceptualization, and when attempting to manipulate control, directly measure perceived control. The relation between PC and health outcomes is complex, and different aspects of PC may interact to affect health outcomes.     

Optimism, neuroticism, coping, and symptom reports: an alternative interpretation of the Life Orientation Test

Found in two studies that the Life Orientation Test (LOT) had limited discriminant validity relative to measures of neuroticism. Furthermore, although previous correlations of the LOT with measures of symptom reports and coping behaviors were replicated, these correlations were eliminated when neuroticism was controlled. In contrast, the correlations of symptoms and coping with neuroticism remained significant when LOT scores were controlled. Thus, the LOT is virtually indistinguishable from measures of neuroticism, and previously reported findings using this scale are perhaps more parsimoniously interpreted as reflecting neuroticism rather than optimism. These findings are discussed in terms of existing support for models of optimism and self-control and general methodological issues in studies of personality and health.