The relationship between cerebral hemisphere volume and receptive language functioning in dyslexia and attention-deficit hyperactivity disorder (ADHD).

Because poor comprehension has been associated with small cerebral volume and there is a high comorbidity between developmental dyslexia, attention-deficit hyperactivity disorder (ADHD), and specific language impairment, the goal of this study was to determine whether cerebral volume is reduced in dyslexia and attention-deficit hyperactivity disorder in general, as some suggest, or whether the reduction in volume corresponds to poor receptive language functioning, regardless of the diagnosis. Participants included 46 children with and without dyslexia and attention-deficit hyperactivity disorder, aged 8 to 12 years. Our results indicated that cerebral volume was comparable between those with and without dyslexia and attention-deficit hyperactivity disorder overall.

A quantitative magnetic resonance imaging analysis of the cerebellar deficit hypothesis of dyslexia.

Recent evidence suggests that the primary source of dysfunction in dyslexia is the cerebellum. To examine the cerebellar deficit hypothesis of dyslexia, 20 children with dyslexia and 20 children without dyslexia were assessed using neuropsychological testing and quantitative magnetic resonance imaging. Results demonstrated that the volumes of both hemispheres and the vermis were not statistically significantly different between groups.

Memory prediction accuracy in younger and older adults: a cross-sectional and longitudinal analysis.

Across three experiments, the effects of age and normative information on memory prediction accuracy were examined. In Experiment 1, younger and older adults were given an arbitrary midpoint anchor and made global predictions about how they expected to perform on subsequent verbal, visual, and name-face memory tasks. In Experiment 2, the normative information was varied by providing participants with a midpoint anchor, accurate anchor, or no anchor.