Nightmare disorder is a prevalent parasomnia characterized by vivid and highly unpleasant dream experiences during night time sleep. The neural background of disturbed dreaming was proposed to be associated with impaired prefrontal and fronto-limbic functioning during REM sleep. We hypothesized that the impaired prefrontal and fronto-limbic…

Anxiety is typically considered an impediment to cognition. We propose anxiety-related impairments in cognitive-behavioral performance are the consequences of enhanced stimulus-driven attention. Accordingly, reflexive, habitual behaviors that rely on stimulus-driven mechanisms should be facilitated in an anxious state, while novel, flexible…

The processing-speedtheory and the prefrontal-executivetheory are competing theories of cognitive aging. Here we used a theoretically and methodologically-driven framework to investigate the relationships among measures classically used to assess these two theoretical constructs. Twenty-eight young adults (18-32 years) and 39 healthy older adults…

Physical and Name Identity letter-matching tasks were used to explore differences in interhemispheric collaboration in younger and older adults. To determine whether other factors might also be related to across/within-hemisphere processing or visual field asymmetries, neuropsychological tests measuring frontal/executive functioning were…

This study aims to investigate the types of difficulty encountered by children with nonverbal (visuospatial) learning disabilities (NLD) during the processing of spatial information derived from descriptions. Two spatial descriptions--one in survey, one in route perspective--and one nonspatial description were orally presented to children aged…

Background: Diffusion tensor imaging (DTI) has revealed microstructural aspects of adolescent brain development, the cognitive correlates of which remain relatively uncharacterized. Methods: DTI was used to assess white matter microstructure in 18 typically developing adolescents (ages 16-18). Fractional anisotropy (FA) and mean diffusion (MD)…

Both emotional reactivity and categorization have long been studied within the framework of hemispheric asymmetry. However, little attempt has been made to integrate both research areas using any form of neuropsychological research, despite behavioral data suggesting a consistent relationship between affective and categorization processes. The…

In recent years, an exciting thrust in the developmental research literature has been the focus on ''executive'' functions (EF). However, the emphasis has been on the more purely cognitive aspects of EF operative in abstract reasoning and problem solving-aspects associated mainly with dorsolateral frontal regions. Although the literature on adult…

Slowness in obsessive-compulsive disorder (OCD) has been attributed to intrusive thoughts or meticulousness. Recent research suggests that slowness in OCD may be particularly evident on tests of executive function subserved by frontostriatal circuitry. In the present study, the speed and accuracy of responding on neuropsychological tests of…

Core symptoms of Tourette's syndrome (TS) and obsessive-compulsive disorder (OCD) may be attributed to an impairment in inhibitory control. Neuropsychological studies have addressed inhibition in both disorders, but findings have been inconsistent. The aim of this study was to examine cognitive inhibition, using a semantic Simon effect paradigm,…

Two experiments are reported that examine the possibility that exercise selectively influences different types of cognition. To our knowledge, these experiments represent the first attempt to study higher-cognitive processes during exercise. Theoretical thinking was guided by the transient hypofrontality hypothesis. In both experiments, athletes…

N400 is an event-related brain potential that indexes operations in semantic memory conceptual space, whether elicited by language or some other representation (e.g., drawings). Language models typically propose three stages: lexical access or orthographic- and phonological-level analysis; lexical selection or word-level meaning and associate…

Evoked potential studies have demonstrated that musicians have the ability to distinguish musical sounds preattentively and automatically at the temporal, spectral, and spatial levels in more detail. It is however not known whether there is a difference in the early processes of auditory data processing of musicians. The most emphasized and…

Background: Brain morphology and physiological measures in schizophrenia have yielded inconsistent results. This may be due in part to difficulties in ascertaining precisely to what degree each measure deviates from its genetically and environmentally determined potential level. We attempted to surmount this problem in a paradigm involving…

Neuropsychological and neuroimaging studies implicate attentional difficulties in obsessive-compulsive disorder (OCD), but results are inconsistent due possibly to sample heterogeneity and lack of control of comorbid disorders, such as Tourette's syndrome (TS). Nevertheless, it has been suggested that OCD symptomatology may be a result of…