In summary, our ITC data suggest that the typical window of 4-8 Hz for theta largely captures the synchronous feedback activity coincident with the feedback negativity (we observed 4.5-8 Hz). In turn, the greater phase locking of theta for no win vs. win feedback (ITC Condition Effect 1), was absent for the 10-12-year-olds, but emerged for the older groups. A later effect (~350-450 ms × 4-5 Hz; ITC Age Effect 2) similarly suggested a lack of differentiation for no- win vs. win feedback among the younger group, which emerges across the middle and older adolescent groups. Moreover, differences across the age groups (Condition Effect, Age Effect 2) indicate a quadratic pattern for no win theta ITC, reduced at 10-12 years, increased at 13-14 years and then decreased again for the 15-17-year-old group. A second, early aspect of feedback processing (~150-250 ms × 4-6 Hz; ITC Age Effect 1), reflected greater trial-to-trial coherence, irrespective of condition, for the younger groups, which was markedly reduced for the older group.
