P46. Neuronal mechanisms of error monitoring in motivational context in healthy children and adolescents

Abstract

Introduction Flexible goal-directed behaviour requires an adaptive cognitive control system for context-specific organization and optimization of information processing. Because the continuous monitoring of the outcome of ongoing actions as well as the subject's motivation are essential for adaptive control over one's own performance, neuronal mechanisms of post-error processing were investigated in the motivational context of trials with different incentive load. These mechanisms were characterized in terms of changes of post-error oscillatory processes in a Go-NoGo task performed in MEG scanner. Developmental influences on neuronal mechanisms of error monitoring in the context of motivation were studied in different age groups of healthy children and adolescents. Methods Fifteen healthy right-handed children aged 10–16years participated as subjects. The Go-NoGo task was applied in two conditions: (A) standard Non-incentive Go-NoGo , and (B) rewarded Incentive Go-No-Go with two reward valences: reward for successful inhibition and response cost for error (for detailed description see Liddle et al., 2011; Mazaheri et al., 2009). The visual stimuli were single digits between 1 and 9 presented in the lower left visual field. Non-incentive Go-NoGo : each stimulus was displayed for 0.2 s and the inter-trial interval was 1.5s. Participants were asked to respond to all digits except of by pressing a button with the right index finger. Digits 1–4 and 6–9 are thus the Go stimuli and digit the NoGo stimulus. Incentive Go-NoGo : the procedure was as in the non-incentive condition with a one difference: for each successful NoGo the subjects obtained a point, and for each false alarm they lost 5 points. The MEG data were acquired using a 275-channel whole-head MEG system (Omega 2005, CTF-MEG, VSM MedTech Inc., Coquitlam, Canada). Results In the non-incentive Go-NoGo condition, there was a significant increase of power in the theta frequency band in the dorsolateral and medial prefrontal cortex bilaterally immediately after an error and reduction of alpha power in the parietal cortex 200–800ms after an error ( p p =0.028). In these regions, there was a reduction of alpha activity in the condition without motivation and an increase in the motivational context. The described changes were more pronounced in adolescents than in children. Conclusion The error monitoring and adaptive post-error optimization in children and adolescents is based on the neuronal signature related to the increase in activity in the prefrontal cortex and decrease in the regions of the default mode network. The increased motivation causes significant changes in pre-activation in the central motor region. The study illustrates neuronal mechanisms responsible to the improvement of performance in the motivation context.