Finally, this difference in CNV amplitude in the late time interval between high-difficulty and low-difficulty cues in reward trials was related to performance during target processing in that it correlated with the high-versus-low difficulty difference in the RTs to the following potentially rewarding target (r=−0.5, p=0.017; see figure 3C). In contrast, the difference in late CNV amplitude between high-difficulty and low-difficulty cues without a potential reward and the corresponding difficulty effect in RTs to the target was not significant (p=0.7). Moreover, no significant correlation was found between reward and no-reward differences for RTs and early and late CNV amplitude (respectively p=0.76 and p=0.38).
