Flanker-Task in Children Time-Frequency Analyses of Response Monitoring

Response processing may comprise multiple systems working in parallel at different functional levels of performance monitoring. In time-frequency decompositions of response-locked event-related potentials from adults, a subprocess operating in the delta frequency band was interpreted as an index of cognitive error monitoring, distinguishable from a process with theta frequency probably related to motor control. However, it remains unclear whether such subprocesses can also be distinguished in children. In the current study, error processing was assessed in 22 normal boys aged 8 to 15 years using an Erikson Flanker task. Performance data revealed the expected indices of conflicting task demands, such as increased reaction times and error rates. A clear error-negativity was found in the response-locked event-related potentials after incompatible stimuli, and correct responses show a slow negative deflection immediately preceding the button-press, which is absent in errors. Time-frequency decompositions disclosed that a subprocess in the lower delta band preceding correct responses may reflect a more general action monitoring process sensitive to conflicting task demands that, moreover, may prevent one from making an error if it is active early enough. Processes in the delta and theta bands are modulated specifically by errors and may index motor-related monitoring in children. Moreover, these processes occurred considerably earlier for correct responses compared to errors, suggesting that their timing reflects some performance capacity. These considerations may help to clarify response processing in tasks with conflicting demands.