In terms of phase coherence, our ITC analysis yielded stronger effects, surviving the FDR procedure. We observed an approximate 200-400 ms by4.5 Hz to 8 Hz condition effect, with greater ITC for no win vs. win, consistent with the typical time window of the FRN. This effect was qualified by a Condition by Age interaction, partly driven by the 10-12-year-old group, who showed comparable ITC for the win and no win conditions. Both the 13-14 year-olds and the 15-17-year olds displayed greater ITC for no win vs. win. Two ITC age effects emerged irrespective of condition, before aggregating for summary effects. The first reflected a reduction in overall phase coherence in the 15-17-year-old group compared to the younger groups from 150-250 ms and 4-6 Hz. The second effect, when examined in aggregate, resembled the ITC condition effect. Specifically we observed an age by condition interaction from 350-450 ms in the 4-5 Hz range, again reflecting a lack of ITC difference for the 10-12-year-old group, but significantly greater ITC for no win compared to win for the older groups. These findings suggest that the transition from childhood to adolescence is reflected by greater phase consistency of the theta oscillations following non-rewards.
