condition strongly suggests that is it not contingent on a motor response. Still, FRN peak latencies during button presses, as identified in the grand mean CSD waveforms, were about 75 ms longer for patients compared to controls, thereby approximating but not fully matching the 115-ms slower response latency of patients. While it is possible that the larger FRN amplitude during button press than silent count (cf. trend in Table 2), which was supported for the larger sample of healthy adults,48 may reflect an incomplete motor response or response inhibition, as suggested by Go/NoGo response tasks,28,97–99 the blocked assignment of response mode should have eliminated the need to inhibit motor responses during silent count; however, given the lack of NoGo trials in the present paradigm, these issues are beyond the scope of this report. As we have previously interpreted this stimulus-locked CSD component as an index of processes linked to response selection, evaluation, or monitoring,48 it is of interest to note that there were no group differences in the overall FRN amplitude, that is, neither in its midfrontal sink nor in its centroparietal source. This suggests that patients did not show evidence of any response monitoring deficit91,92 during these tonal and
