The sensitivity of a palm-based psychomotor vigilance task to severe sleep loss

In this study, we evaluated the sensitivity of a 5-min personal digital assistant-psychomotor vigilance test (PDA-PVT) to severe sleep loss. Twenty-one participants completed a 10-min PVT-192 and a 5-min PDA-PVT at two hourly intervals during 62 h of sustained wakefulness. For both tasks, response speed and number of lapses (RTs > 500) per minute significantly increased with increasing hours of wakefulness. Overall, standardized response speed scores on the 5-min PDA-PVT closely tracked those of the PVT-192; however, the PDA-PVT was generally associated with more lapses/minute. Closer inspection of the data indicated that when the level of sleep loss and fatigue became more severe (i.e., Day 3), the 5-min PDA-PVT was not quite as sensitive as the 10-min PVT-192 when 2- to 10-sec foreperiods were used for both. It is likely, however, that the observed differences between the two devices was due to differences in task length. Thus, the findings provide further evidence of the validity of the 5-min PDA-PVT as a substitute for the 10-min PVT-192, particularly in circumstances in which a shorter test is required and/or the PVT-192 is not as practical.     

Body checking behaviors in men

Males have been facing increasing pressure from the media to attain a lean, muscular physique, and are at risk for body dissatisfaction, disturbed eating and exercise behaviors, and abuse of appearance- and performance-enhancing drugs (APEDs). The aim of the current study was to examine the relationship between body checking and mood, symptoms of muscle dysmorphia, importance of shape and weight, and APED use in undergraduate males. Body checking in males was correlated with weight and shape concern, symptoms of muscle dysmorphia, depression, negative affect, and APED use. Body checking predicted APED use and uniquely accounted for the largest amount of variance in Muscle Dysmorphic Disorder Inventory (MDDI) scores (16%). Findings support the view that body checking is an important construct in male body image, muscle dysmorphia, and body change strategies and suggest a need for further research.     

A comparison of laboratory and clinical working memory tests and their prediction of fluid intelligence

The working memory (WM) construct is conceptualized similarly across domains of psychology, yet the methods used to measure WM function vary widely. The present study examined the relationship between WM measures used in the laboratory and those used in applied settings. A large sample of undergraduates completed three laboratory-based WM measures (operation span, listening span, and n-back), as well as the WM subtests from the Wechsler Adult Intelligence Scale-III and the Wechsler Memory Scale-III. Performance on all of the WM subtests of the clinical batteries shared positive correlations with the lab measures; however, the Arithmetic and Spatial Span subtests shared lower correlations than the other WM tests. Factor analyses revealed that a factor comprising scores from the three lab WM measures and the clinical subtest, Letter-Number Sequencing (LNS), provided the best measurement of WM. Additionally, a latent variable approach was taken using fluid intelligence as a criterion construct to further discriminate between the WM tests. The results revealed that the lab measures, along with the LNS task, were the best predictors of fluid abilities.     

Anticipation of future food: suppression and facilitation of saccharin intake depending on the delay and type of future food

A series of studies examined the (Sprague-Dawley) rat's tendency to suppress intake of .15% saccharin when it was followed by a second food after 4-, 16-, or 32-min delays. The second foods examined were 32% sucrose, 64% sucrose, lab chow, a Nutrasweet solution, skim milk, and chocolate milk. Saccharin intake was influenced by both the delay and the specific food available. Subsequent analysis showed that saccharin intake before the 4-min delay was an inverse function of the caloric value of the second food. However, saccharin intake before the 16-min delay was better predicted as an inverse function of the hedonic value of the second food. The results suggest that the caloric and hedonic values of a food may influence food selection across different time courses, and that the effective time horizon for the sequential comparison of foods depends on the specific foods that are compared.     

Criterion-referenced and norm-referenced assessment of minority group children

A variety of problems have been experienced with psychological assessment of minority children. Traditional norm-referenced measurement has repeatedly received criticism concerning cultural unfairness or bias. Responses to such accusations primarily have been in the form of new instrumentation aimed at attaining a culture fair assessment. Little response has been evident from a conceptual standpoint addressing the issues of purpose and use of test results Although many have turned to criterion-referenced measurement as an answer to the problems of norm-referenced evaluation, cultural bias is not necessarily avoided in this framework either. Issues of who determines criteria and what those criteria include must be addressed if criterion-referenced measurement is to meet adequately the challenge of multicultural evaluation.     

Target position and practice in the identification of letters in varying contexts: A word superiority effect

A forced-choice detection paradigm controlling for postperceptual inference was used to investigate letter identification in three-position displays. Letters from a predesignated set of four targets appeared singly, in strings of noise characters, in unpronounceable nonsense strings, and in words. Subjects knew which context would occur, but did not know which of the three display positions would contain the target. Correct detection data were collected at constant exposure duration over five testing sessions. Overall identification accuracy was higher in words than in all other contexts, the first word superiority effect to be found with targets specified in advance since Reicher’s (1969). This effect remained constant over sessions. An interaction between context type and target position showed enhanced accuracy for initial and terminal letters in words, but depressed accuracy at initial and terminal positions in other contexts. This was interpreted to mean that prior knowledge of context is used to alter the dynamics of perceptual analysis.