Investigating response conflict processes in 7 and 9-year old children: An EEG study using coherence

Assessing cognitive development in children is of paramount importance in understanding the development of critical neural pathways of the brain. In particular, recognition of stimuli, task accuracy and response time are key features that can inform on stages of brain cognition with respect to age and within age group differences. In this study we investigate neurophysiological responses of the Eriksen Flanker task - an experimental paradigm for assessing attention and cognition - in middle childhood ages (seven-nine years). We analyse EEG data in two age groups: 45 healthy subjects aged seven years with a follow-up study on the same subjects at age nine years. We examine spectral coherence - a method for analysing the correlation between electrode pairs - for all possible combination of pairs. Comparisons of coherence values based on Flanker task conditions (incongruent versus congruent) were assessed in each age group. Consequently, these assessments were used as indicators to the cognitive conflict induced by Flanker incongruent stimuli. For both age groups (seven and nine years) inter-hemispherical coherence increased in the right hemisphere. Moreover, the older children showed less Flanker conflict compared with children aged seven years, especially within the theta band. This decrease in the effect of the cognitive conflict may indicate age-related cognitive developments.