Planum temporale morphology in children with developmental dyslexia.

The planum temporale is a highly lateralized cortical region, located within Wernicke's area, which is thought to be involved in auditory processing, phonological processing, and language. Research has linked abnormal morphology of the planum temporale to developmental dyslexia, although results have varied in large part due to methodological inconsistencies in the literature. This study examined the asymmetry of the planum temporale in 29 children who met criteria for dyslexia and 26 children whose reading was unimpaired.

Reading fluency: implications for the assessment of children with reading disabilities.

The current investigation explored the diagnostic utility of reading fluency measures in the identification of children with reading disabilities. Participants were 50 children referred to a university-based clinic because of suspected reading problems and/or a prior diagnosis of dyslexia, where children completed a battery of standardized intellectual, reading achievement, and processing measures. Within this clinical sample, a group of children were identified that exhibited specific deficits in their reading fluency skills with concurrent deficits in rapid naming speed and reading comprehension.

Testing the double-deficit hypothesis in an adult sample.

The double-deficit hypothesis of dyslexia posits that reading deficits are more severe in individuals with weaknesses in phonological awareness and rapid naming than in individuals with deficits in only one of these reading composite skills. In this study, the hypothesis was tested in an adult sample as a model of reading achievement. Participants were parents of children referred for evaluation of reading difficulties.

Right hemisphere brain morphology, attention-deficit hyperactivity disorder (ADHD) subtype, and social comprehension.

Social comprehension involves empathy for others' experiences and appropriate responses to nonverbal cues. Previous research using magnetic resonance imaging (MRI) has suggested a relationship between brain morphology and psychiatric syndromes, such as attention-deficit hyperactivity disorder (ADHD), that typically entail social difficulties. The right hemisphere, specifically, has been associated with social skill deficits, and numerous studies have also associated ADHD with social skill deficits.

The role of the corpus callosum in interhemispheric transfer of information: excitation or inhibition?

The corpus callosum is the major neural pathway that connects homologous cortical areas of the two cerebral hemispheres. The nature of how that interhemispheric connection is manifested is the topic of this review; specifically, does the corpus callosum serve to communicate an inhibitory or excitatory influence on the contralateral hemisphere? Several studies take the position that the corpus callosum provides the pathway through which a hemisphere or cortical area can inhibit the other hemisphere or homologous cortical area in order to facilitate optimal functional capacity. Other studies suggest that the corpus callosum integrates information across cerebral hemispheres and thus serves an excitatory function in interhemispheric communication.