Linear and nonlinear categorization rule learning was examined in patients with Huntington's disease (HD) and a group of controls using the perceptual categorization task. Participants learned to categorize simple line stimuli into 1 of 2 categories over 600 trials. In addition to traditional measures of accuracy, quantitative model-based analyses were applied to each participant's data to char...

Although categorization is fundamental to speech processing, little is known about the learning systems that mediate auditory categorization and even less is known about changes across the life span. Vision research supports dual-learning systems that are grounded in neuroscience and are partially dissociable. The reflective, rule-based system is prefrontally mediated and uses working memory an...

Several studies have provided evidence for a phonological deficit in developmental dyslexia. However, recent studies provide evidence for a multimodal temporal processing deficit in dyslexia. In fact, dyslexics show both auditory and visual abnormalities, which could result from a more general problem in the perceptual selection of stimuli. Here we report the results of a behavioral study showi...

Previous research on cognitive set shifting in patients with Parkinson's disease has often been confounded by concept formation, rule learning, working memory and/or general slowing of cognitive processes. To circumvent this problem, the present study used the task-set switching procedure in which good performance was independent of rule learning, and in which working memory load was reduced by...

Attention Deficit Disorder and Specific Learning Disorders Attention Deficit Hyperactivity Disorder, (ADHD) is characterized by impulsivity, hyperactivity, and distractibility. These symptoms may be present in varying degrees. For example, hyperactivity may not necessarily be obtrusive in order to diagnose the condition. ADHD is not a disease. There is no single diagnostic test. It is diagnosed...

Cognitive impairment in epileptics may be a consequence of the epileptogenic process as well as antiepileptic medication. Thus, there is need for drugs, which can suppress epileptogenesis as well as prevent cognitive impairment. In the present study, the effect of Khamira Marwarid (KAH 1 ), a formulation based on Indian system of Unani medicine, was evaluated on the course of pentylenetetrazole...

Dyslexia is a common learning disability, but its core deficit is still under debate. The anchoring deficit hypothesis suggests that dyslexics’ benefit from experimental stimuli statistics is impaired (e.g. Ahissar, 2007). In this study we asked whether dyslexia is also associated with reduced sensitivity to long-term statistics. Spans for lists of syllables were measured, and indeed, dyslexics...

Neurofibromatosis type 1 (NF1) is the most common monogenic disorder in which individuals manifest CNS abnormalities. Affected individuals develop glial neoplasms (optic gliomas, malignant astrocytomas) and neuronal dysfunction (learning disabilities, attention deficits). Nf1 genetically engineered mouse models have revealed the molecular and cellular underpinnings of gliomagenesis, attention d...

OBJECTIVE This study uses the Attribution Style Questionnaire (ASQ) to measure the causal thinking of 42 college students with diagnosed language-based learning disabilities (LD), ADHD, or co-occurring ADHD and LD. Attribution style, or explanatory style, is a term used to describe the tendencies of individuals to think that the causes of meaningful events are internal or external, global or sp...