Results showed widespread NADPH-oxidase inhibitor group differences in the categorical representation of semantic knowledge in several language-related brain areas. For example, the right inferior frontal gyrus showed selective brain response for nonliving items in the CN group but living items in the AD group. Additionally, the AD group showed increased brain response for word retrieval irrespective of category in Broca’s homologue in the right hemisphere and rostral cingulate cortex bilaterally, which suggests greater recruitment of frontally mediated neural compensatory mechanisms in the face of semantic alteration. Published by Elsevier
Ltd.”
“Errors in speeded decision tasks are associated with characteristic patterns of brain activity.
In the scalp-recorded EEG, error processing is reflected in two components, the error-related negativity (ERN) and the error positivity (Pe). These components have been widely studied, but debate remains regarding the precise aspects of error processing they reflect. The present study investigated the relation between the ERN and the Pe using a novel version of the flanker task to allow a comparison between errors reflecting different causes response conflict versus stimulus masking. The conflict and mask conditions were matched for overall behavioural performance but differed in underlying response dynamics, MG-132 manufacturer as indexed by response time distributions and measures of lateralised motor activity. ERN amplitude varied in relation to these differing response dynamics,
being significantly larger in the conflict condition compared to the mask condition. Furthermore, differences in response dynamics between participants were predictive of modulations in ERN amplitude. In contrast, Pe activity varied little between conditions, but varied across Amisulpride trials in relation to participants’ awareness of their errors. Taken together, these findings suggest a dissociation between the ERN and the Pe, with the former reflecting the dynamics of response selection and conflict, and the latter reflecting conscious recognition of an error. (C) 2010 Elsevier Ltd. All rights reserved.”
“Neuroimaging studies on attention-deficit/hyperactivity disorder (ADHD) suggest dysfunctional reward processing, with hypo-responsiveness during reward anticipation in the reward system including the nucleus accumbens (NAcc). In this study, we investigated the association between ADHD related behaviors and the reward system using functional magnetic resonance imaging in a non-clinical sample. Participants were 31 healthy, female undergraduate students with varying levels of self-reported ADHD related behaviors measured by the adult ADHD self-report scale.