No abstract

The current study investigated contradictory findings from recent experimental and meta-analytic studies concerning working memory deficits in ADHD. Working memory refers to the cognitive ability to temporarily store and mentally manipulate limited amounts of information for use in guiding behavior. Phonological (verbal) and visuospatial (nonverbal) working memory were assessed across four memory load conditions in 23 boys (12 ADHD, 11 typically developing) using tasks based on Baddeley's (Working memory, thought, and action, Oxford University Press, New York, 2007) working memory model. The model posits separate phonological and visuospatial storage and rehearsal components that are controlled by a single attentional controller (CE: central executive). A latent variable approach was used to partial task performance related to three variables of interest: phonological buffer/rehearsal loop, visuospatial buffer/rehearsal loop, and the CE attentional controller. ADHD-related working memory deficits were apparent across all three cognitive systems--with the largest magnitude of deficits apparent in the CE--even after controlling for reading speed, nonverbal visual encoding, age, IQ, and SES.

SummaryVery little research has investigated whether believing in paranormal, conspiracy, and pseudoscientific claims are related, even though they share the property of having no epistemic warrant. The present study investigated the association between these categories of epistemically unwarranted beliefs. Results revealed moderate to strong positive correlations between the three categories of epistemically unwarranted beliefs, suggesting that believers in one type tended to also endorse other types. In addition, one individual difference measure, looking at differences in endorsing ontological confusions, was found to be predictive of both paranormal and conspiracy beliefs. Understanding the relationship between peoples' beliefs in these types of claims has theoretical implications for research into why individuals believe empirically unsubstantiated claims. Copyright © 2014 John Wiley & Sons, Ltd.

Two experiments examined whether video game expertise transfers to performance on measures of spatial ability. In Experiment 1, skilled Tetris players outperformed non-Tetris players on mental rotation of shapes that were either identical to or very similar to Tetris shapes, but not on other tests of spatial ability. The pattern of performance on those mental rotation tasks revealed that skilled Tetris Players used the same mental rotation procedures as non-Tetris players, but when Tetris shapes were used, they executed them more quickly. In Experiment 2, non-Tetris players who received 12 hours of Tetris-playing experience did not differ from matched control students in pretest-to-posttest gains on tests of spatial ability. However, Tetris-experienced participants were more likely to use an alternative type of mental rotation for Tetris shapes than were Tetris-inexperienced participants. The results suggest that spatial expertise is highly domain-speci®c and does not transfer broadly to other domains.

In three experiments we tested the effects of spatial visualization ability on performance of a motion-verification task, in which subjects were shown a diagram of a mechanical system and were asked to verify a sentence stating the motion of one of the system components. We propose that this task involves component processes of (1) sentence comprehension, (2) diagram comprehension, (3) text-diagram integration, and (4) mental animation. Subjects with low spatial ability made more errors than did subjects with high spatial ability on this task, and they made more errors on items in which more system components had to be animated to solve the problem. In contrast, the high-spatial subjects were relatively accurate on all trials. These results indicate that spatial visualization is correlated with accuracy on the motion-verification task and suggest that this correlation is primarily due to the mental animation component of the task. Reaction time and eye-fixation data revealed no differences in how the high- and low-spatial subjects decomposed the task. The data of the two groups of subjects were equally consistent with a piecemeal model of mental animation, in which components are animated one by one in order of the causal chain of events in the system.