Differential effects of left and right cerebral vascular accidents on language competency.

While language facility was once considered to be the sole province of the "dominant" left hemisphere, clinical and experimental findings suggest the right hemisphere plays an equally important role in many language tasks. To elucidate differential hemispheric language processes, Right Hemisphere Language Battery and Western Aphasia Battery data from left (LHD) and right (RHD) hemisphere cerebral vascular accident (CVA) patients and controls were subjected to multivariate discriminant analysis. The highly significant group differences and overall 95% classification rate obtained confirms the utility of the dependent measures in differential diagnosis. Results suggest CVA patients experience disparate language deficits, with the LHD group experiencing concordant-convergent language deficits and the RHD group displaying discordant-divergent deficits that interfere with the receptive and expressive language skills necessary for successful social discourse.

Evaluating medication response in ADHD: cognitive, behavioral, and single-subject methodology.

Although evidence supports the use of double-blind placebo medication trials to evaluate methylphenidate (MPH) effects on the core behavioral symptoms of attention-deficit/hyperactivity disorder (ADHD), few studies have demonstrated their utility in examining MPH effects on the cognitive deficits associated with ADHD. This article presents a technique for evaluating behavioral and cognitive dose-response relationships at the single-subject level of analysis. Case study results and multivariate analyses suggest that systematic evaluation of behavioral and cognitive MPH dose-response relationships could lead to more accurate MPH titration and greater long-term multimodal treatment efficacy.