Reliability and Validity of a DSM-IV Based ADHD Screener

The Diagnostic Rating Scale (DRS) was completed by the parents and teachers of 82 children referred for clinical evaluations, 73 referred children seen twice, and 218 non-referred children from the community. The DRS, which uses a categorical rather than a dimensional rating approach, was 70% to 90% sensitive to diagnoses of Attention Deficit/Hyperactivity Disorder (ADHD) made by blind clinical teams. In research and clinical applications, the DRS could improve screening efficiency, especially in situations where it would be desirable to exclude all children who might have ADHD or identify all children with Hyperactive-Impulsive symptoms. Because of its objectivity and consistency with the Diagnostic and Statistical Manual (DSM)-IV criteria, the DRS could facilitate comparison of participant samples across studies.     

Rats’ memory for time and relational responding in the duration-comparison procedure

Rats were trained in a duration-comparison task to press one lever if the comparison duration (c) was 1.2-s shorter than a standard duration (s), and another lever if c was 1.2-s longer than s. The interval between s and c duration was 1 s. The 10 duration pairs used during training controlled for the absolute duration of c and the total duration of an s-c pair. The total duration of an s-c pair was not predictive of the correct response. In Experiment 1, during equal-duration pair test trials, rats increasingly responded long (i.e., c > s) as the s-c delay was lengthened. In Experiment 2, long responding increased as the s-c delay was lengthened, even when the illumination condition during the s-c delay differed from that during the intertrial interval (ITI). In Experiment 3, transfer to novel duration pairs was assessed. Overall accuracy for the novel duration pairs was significantly above chance, but transfer performance was also affected by the absolute value of the novel c durations. This is the first study to demonstrate that rats can acquire relational duration discriminations. As in previous studies with pigeons the evidence was consistent with subjective-shortening of the standard duration and there was also evidence of a reliance on a mixture of absolute and relational strategies in responding.     

Co-regulation of movement speed and accuracy by children with heavy prenatal alcohol exposure

The study investigated how children with heavy prenatal alcohol exposure regulate movement speed and accuracy during goal-directed movements. 16 children ages 7 to 17 years with confirmed histories of heavy in utero alcohol exposure, and 21 nonalcohol-exposed control children completed a series of reciprocal tapping movements between two spatial targets. 5 different targets sets were presented, representing a range of task difficulty between 2 and 6 bits of information. Estimates of percent error rate, movement time, slope, and linear fit of the resulting curve confirmed that for goal-directed, reciprocal tapping responses, performance of the group with prenatal alcohol exposure was described by a linear function, as predicted by Fitts' law, by sacrificing movement accuracy. The index of performance was the same for the two groups: it initially increased, then leveled off for more difficult movements.     

Distinctions Between Two Expectancies in the Prediction of Maladaptive Eating Behavior

In this longitudinal study, the authors provide support for the validity of the claim that differences in the nature of the reinforcement that adolescent girls expect from eating contribute to the development of different forms of maladaptive eating. The learned expectancy that eating is pleasurable and rewarding predicted higher levels of social/celebratory overeating across the first year of middle school but did not predict higher levels of clinical binge eating. In contrast, the expectancy that eating helps one manage negative affect predicted higher levels of binge eating but not of social/celebratory overeating across the same time period (n = 394). The results also supported a reciprocal model in which binge eating predicted higher levels of the expectancy that eating will manage negative affect but not that eating is pleasurable and rewarding; conversely, social/celebratory overeating predicted higher levels of the expectancy that eating is pleasurable and rewarding but not that eating will manage negative affect.     

False-positive psychology: undisclosed flexibility in data collection and analysis allows presenting anything as significant

In this article, we accomplish two things. First, we show that despite empirical psychologists' nominal endorsement of a low rate of false-positive findings (≤ .05), flexibility in data collection, analysis, and reporting dramatically increases actual false-positive rates. In many cases, a researcher is more likely to falsely find evidence that an effect exists than to correctly find evidence that it does not. We present computer simulations and a pair of actual experiments that demonstrate how unacceptably easy it is to accumulate (and report) statistically significant evidence for a false hypothesis. Second, we suggest a simple, low-cost, and straightforwardly effective disclosure-based solution to this problem. The solution involves six concrete requirements for authors and four guidelines for reviewers, all of which impose a minimal burden on the publication process.     

Different components of working memory have different relationships with different mathematical skills

A comprehensive working memory battery and tests of mathematical skills were administered to 90 children-41 in Year 1 (5-6 years of age) and 49 in Year 3 (7-8 years of age). Working memory could explain statistically significant variance in number writing, magnitude judgment, and single-digit arithmetic, but the different components of working memory had different relationships with the different skills. Visual-spatial sketchpad (VSSP) functioning predicted unique variance in magnitude judgments and number writing. Central executive functioning explained unique variance in the addition accuracy of Year 1 children. The unique variance explained in Year 3 multiplication explained by phonological loop functioning just missed conventional levels of significance (p=.06). The results are consistent with the VSSP having a role in the development of number writing and magnitude judgments but a lesser role in early arithmetic.