Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.21 (CPT)
 4,580 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present developmental study aimed to trace changes in response expectation, preparation, conflict monitoring and subsequent response inhibition from 6 years of age to adulthood. In two groups of children (6-7 and 9-10 years old) and young adults (19-23 years old), behavior and event-related brain activity (ERP) in a CPT-AX task was measured. Hits, false alarms, inattention and impulsivity scores and ERP measures of conflict monitoring and inhibition (Nogo-N2 and P3), cue-orientation and prestimulus target expectation (cue-P2 and P3) and response preparation (Contingent Negative Variation; CNV) were collected. Behavioral measures indicated that attention processes developed most strongly before age 10, whereas impulsive behavior only started to diminish after the age of 10. Nogo-N2 effects were largest and more widely distributed across fronto-parietal electrodes in 6-7-year olds and decreased linearly with age. Nogo-P3 effects showed an opposite pattern by being absent in the youngest children, starting to develop at age 9-10 and reaching maturity in young adulthood. These developmental behavioral and ERP results are supportive of links between Nogo-N2 and conflict monitoring and Nogo-P3 and response inhibition and suggest that both are liable to different developmental progress. Furthermore, enhanced cue-P3 activity in both 6-7 and 9-10-year olds was argued to reflect a higher level of Go-stimulus expectation, that might cause them to experience more conflict on subsequent Nogo-trials, when the 'not-expected' stimulus appears. On the other hand, young children's reduced preparatory CNV activity was interpreted as a sign of reduced response priming caused by yet immature fronto-parietal networks involved in motor regulation.
 ...
PMID:The development of preparation, conflict monitoring and inhibition from early childhood to young adulthood: a Go/Nogo ERP study. 1672 77

Twenty male adults with ADHD, 16 dyslexic adults, 15 comorbid adults, and 16 normal controls were compared on performance and underlying brain responses, during a cued Continuous Performance Test (O-X CPT), with the aim of discovering features of information processing differentiating between the groups. The study evaluated both cue- and target-related processes by analysing performance measures (errors, reaction time, and variability of reaction time), and event-related potentials (ERPs). Cue-related ERP components included the Cue-N2, Cue-P3, contingent negative variation (CNV) consisting of the CNV1, related to cue orienting, and the CNV2, related to response preparation. For targets, a distinction was made between response-related (Go), and inhibitory (Nogo) processing. Target-related components included the Go-P3, Nogo-N2, and Nogo-P3. Performance deficits were found only for the ADHD group, who demonstrated a faster decline in response speed with time-on-task and greater overall within-subject variability. No group differences were found for cue-related ERP components. Yet, controlling for group differences in internalising problems, inhibitory control was reduced in all clinical groups compared to controls, as demonstrated by an absence of frontal amplification of P3 in the Nogo condition, relative to the Go condition. For the ADHD group, in contrast to the comorbid and the dyslexic group, this effect remained after controlling for externalising symptoms, indicating that only for the ADHD group deficiencies in inhibitory control were not explained by externalising behaviour.
 ...
PMID:Information processing differences and similarities in adults with dyslexia and adults with Attention Deficit Hyperactivity Disorder during a Continuous Performance Test: a study of cortical potentials. 2060 Jan 94

Cognitive control processes may depend on contextual information, sometimes improving performance, but impairing performance if expectancies about forthcoming events induce pre-potent responses. The neurobiological bases of these effects are not understood. Here, we examine context-dependent variations of response control processes using the AX-CPT task with respect to the relevance of the functional serotonin 1A receptor polymorphism (5-HT1A C(-1019)G) in a sample of healthy subjects (N=90) by means of event-related potentials (ERPs). The results show that, when context information is helpful to drive behavioural performance, carriers of the -1019G allele reveal compromised cognitive control. Yet, they show enhanced task performance when strong context representations would lead to declines in behavioural control. These findings are paralleled by modulations of the (Nogo)-P3 ERP-component. These results show for the first time that, even though the -1019G allele enhances the risk to develop anxiety disorders, it also confers an advantage to its carriers in terms of better cognitive control processes in conditions where contextual information compromises cognitive control. Effects of the 5-HT1A C(-1019)G polymorphism were further modulated by anxiety sensitivity. As the functional effect of the 5-HT1A C(-1019)G polymorphism has previously been shown to be rather specific for serotonergic 1A autoreceptors in the dorsal raphe nucleus (DRN), the results suggest that contextual modulations in cognitive control may be exerted by the DRN.
 ...
PMID:The functional 5-HT1A receptor polymorphism affects response inhibition processes in a context-dependent manner. 2164 34

The attention deficit/hyperactivity disorder (ADHD) shows an increased prevalence in arrested offenders compared to the normal population. The aim of the present study was to investigate whether ADHD symptoms are a major risk factor for criminal behaviour, or whether further deficits, mainly abnormalities in emotion-processing, have to be considered as important additional factors that promote delinquency in the presence of ADHD symptomatology. Event related potentials (ERPs) of 13 non-delinquent and 13 delinquent subjects with ADHD and 13 controls were compared using a modified visual Go/Nogo continuous performance task (VCPT) and a newly developed version of the visual CPT that additionally requires emotional evaluation (ECPT). ERPs were analyzed regarding their topographies and Global Field Power (GFP). Offenders with ADHD differed from non-delinquent subjects with ADHD in the ERPs representing higher-order visual processing of objects and faces (N170) and facial affect (P200), and in late monitoring and evaluative functions (LPC) of behavioural response inhibition. Concerning neural activity thought to reflect the allocation of neural resources and cognitive processing capability (P300 Go), response inhibition (P300 Nogo), and attention/expectancy (CNV), deviances were observable in both ADHD groups and may thus be attributed to ADHD rather than to delinquency. In conclusion, ADHD symptomatology may be a risk factor for delinquency, since some neural information processing deficits found in ADHD seemed to be even more pronounced in offenders with ADHD. However, our results suggest additional risk factors consisting of deviant higher-order visual processing, especially of facial affect, as well as abnormalities in monitoring and evaluative functions of response inhibition.
 ...
PMID:Neurophysiological correlates of delinquent behaviour in adult subjects with ADHD. 2224 45