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Abstract: In a cross-sectional, electrophysiological study 91 workers of a big car factory performed a series of switch tasks to assess their cognitive control functions. Four groups of workers participated in the study: 23 young and 23 middle aged assembly line employees and 22 young and 23 middle aged employees with flexible job demands like service and maintenance. Participants performed three digit categorisation tasks. In addition to single task blocks, a cue-based (externally guided) and a memory-based (internally guided) task switch block was administered. Compared to young participants, older ones showed the typical RT-decline. No differences between younger and older participants regarding the local switch costs could be detected despite the source of the current task information. In contrast, whereas the groups did not differ in mixing costs in the cued condition, clear performance decrements in the memory-based mixing block were observed in the group of older employees with repetitive work demands. These findings were corroborated by a number of electrophysiological results showing a reduced CNV suggesting an impairment of task specific preparation, an attenuated P3b suggesting reduced working memory capacity and a decreased Ne suggesting deficits in error monitoring in older participants with repetitive job demands. The results are compatible with the assumption that long lasting, unchallenging job demands may induce several neurocognitive impairments which are already evident in the early fifties. Longitudinal studies are needed to confirm this assumption. [ABSTRACT FROM AUTHOR]

Abstract: This study compared children with ADHD, reading disorder (RD), ADHD+RD, and control children on behavioural (post-error slowing and post-error accuracy) and event-related potential (Ne and Pe) measures of error monitoring. Children with ADHD did not differ from children without ADHD in post-error slowing but showed less post-error accuracy enhancement, as evidenced by a higher proportion of double-errors. We found a smaller Ne but normal Pe amplitude in children with RD, and a smaller Pe but normal Ne amplitude in children with ADHD. Children from the comorbid group showed both a smaller Ne and a smaller Pe amplitude, which suggests that they showed the additive combination of the deficits found in both separate disorders. The results of the present study suggest that it might be important to control for the presence of comorbid RD when examining error monitoring in ADHD and that various measures of post-error adaptation should be included. [Copyright &y& Elsevier]

Abstract: In a recent experiment [Boksem, M.A.S., Tops, M., Wester, A.E., Meijman, T.F., Lorist, M.M., 2006. Error-related ERP components and individual differences in punishment and reward sensitivity. Brain Research 1101, 92–101], we showed that error-related ERP components were related to punishment and reward sensitivity. The present study was conducted to further evaluate the relationship between punishment/reward sensitivity and these ERP components. Therefore, we scored our subjects on the BIS/BAS measures of punishment and reward sensitivity. Then, subjects performed one of two versions of a Flanker task: in one, they were financially punished for committing errors; in the other, they were financially rewarded for correct performance. Analyses of ERN/Ne amplitudes indicated significant interactions between personality measures of punishment (BIS) and reward (BAS) and actual punishment and reward, while analyses of Pe amplitudes showed significant interactions between personality measures of reward sensitivity and actual reward. We suggest that ERN/Ne amplitude is related to concerns over mistakes and depends on the level of aversion experienced by individual subjects for making these mistakes. Subjects that are highly sensitive to punishment are strongly motivated or engaged in avoiding punishment, while subjects sensitive to rewards are motivated to obtain rewards and therefore show high task engagement when rewards may be earned. The error-related ERP components appear to track this level of engagement in task performance. [Copyright &y& Elsevier]

Abstract: In this study we examined whether the effects of mental fatigue on behaviour are due to reduced action monitoring as indexed by the error related negativity (Ne/ERN), N2 and contingent negative variation (CNV) event-related potential (ERP) components. Therefore, we had subjects perform a task, which required a high degree of action monitoring, continuously for 2h. In addition we tried to relate the observed behavioural and electrophysiological changes to motivational processes and individual differences. Changes in task performance due to fatigue were accompanied by a decrease in Ne/ERN and N2 amplitude, reflecting impaired action monitoring, as well as a decrease in CNV amplitude which reflects reduced response preparation with increasing fatigue. Increasing the motivational level of our subjects resulted in changes in behaviour and brain activity that were different for individual subjects. Subjects that increased their performance accuracy displayed an increase in Ne/ERN amplitude, while subjects that increased their response speed displayed an increase in CNV amplitude. We will discuss the effects prolonged task performance on the behavioural and physiological indices of action monitoring, as well as the relationship between fatigue, motivation and individual differences. [Copyright &y& Elsevier]

Abstract: A recent study reported a positive modulation of the response-locked event-related brain potential (ERP) on trials preceding errors (i.e., error−1 trials). It was proposed that this error-preceding positivity (EPP) reflects the disengagement of the response monitoring system prior to errors. In three studies, we sought to replicate the EPP, and to delineate the conditions under which it can be observed. Study 1 replicated the finding of a positive modulation of the ERP on error-preceding compared to RT-matched correct-preceding trials. This enhanced positivity was not due to differences in stimulus-related processing, and a similar modulation was not observed on error−2 or error+1 trials. Studies 2 and 3 indicated that similar EPP-like phenomena could be observed across a variety of tasks, and using much longer inter-trial intervals. The onset and duration of the modulation, however, did vary between studies. These results are discussed in terms of response-locked ERPs and action monitoring. [Copyright &y& Elsevier]

The error negativity, an EEG wave observed when subjects commit an error in a choice reaction time (RT) task, is often considered as a sign of error detection. Recently, reports of Ne-like waves on correct responses did challenge this interpretation. It has been proposed, however, that these Ne-like waves result either from an artifactual contamination of response-locked activities by stimulus-locked ones, or from an implicit monitoring of the time elapsing during the RT. Our aim was to reprocess published data: (1) to compare the shape and amplitude of EMG-locked and stimulus-locked ERPs on correct trials, and (2) to compare the size of the EMG-locked Ne-like waves obtained on fast and slow trials. The results neither support the artifact hypothesis nor the RT monitoring one. Therefore, it seems that the Ne-like waves observed on correct trials do correspond to a Ne, which suggests that the Ne has a broader significance than just error detection. [Copyright &y& Elsevier]