This study expands our understanding of the role of frontal executive processes beyond the cognitive domain to the cognitive-motor domain.”
“Two experiments examined the hypothesis that dual systems of stimulus evaluation for categorization can be observed in event-related potentials: one whose duration is

indexed by the latency of the P3 component, and a second evident in a later frontal potential. Subjects categorized artificial animals by a “”two out of three”" rule. Stimuli with two visual features of their own category and one feature of a different category (i.e., near the boundary between categories) elicited very prolonged reaction times as compared to stimuli with three features from a single category. This response Alvespimycin in vitro time (RT) delay was not accompanied by a delayed P3, suggesting that the P3 indexed only a first pass of stimulus evaluation. The near-boundary stimuli elicited more positive potentials than far-boundary stimuli at prefrontal and frontotemporal sites, suggesting that a

secondary stage of stimulus evaluation was triggered when detection of single features or simple conjunctions was insufficient to support a correct decision. The frontal potential that was sensitive to categorization difficulty was of opposite polarity to frontal potentials previously observed in manipulations of working memory. The roles of frontal executive processes in categorization and memory tasks are discussed.”
“Both exaggerated and attenuated responses to emotional stimuli have been documented in Generalized Nirogacestat order Anxiety Disorder (GAD). Event-related potentials are well-suited for examining the time-course of neural activity during emotional processing; early components (e.g., the P1) appear to index relatively automatic attention to emotional stimuli, whereas later positivities (e.g., the late positive potential or LPP) index dynamic allocation of attention

to emotional stimuli. Twenty-one individuals with GAD and 25 healthy controls (HC) passively viewed emotional MK-0518 cell line and neutral images while ERPs were recorded. An enhanced P1 for unpleasant compared to neutral images was larger in GAD. In addition, the increased LPP to unpleasant compared to neutral images was diminished in the GAD group. These data provide evidence for early hypervigilance for emotional stimuli, followed by failure to engage in elaborative processing, in GAD.”
“Feedback-related negativity is an event-related brain potential elicited by negative feedback. Its properties make it a valuable tool for the assessment of cognitive-affective processes that are involved in feedback and reward processing. The present study sought to determine the minimum number of trials that are required to obtain a reliable FRN component using a simple gambling paradigm. Three independent groups of young participants and one group of old participants were used. In the experimental conditions with healthy young controls, 20 trials were sufficient to measure the optimal FRN amplitude.