We specifically focused on the theta band for feedback processing of no win and win conditions because the body of adult data suggested the relevance of this frequency range for feedback processing. Our overall spectral plots (Figure 2) are consistent with this choice. However, we could have considered other frequency ranges and other cortical regions that may vary with reward feedback processes. Other work suggests that reward feedback may elicit midfrontal beta band activity(Marco-Pallares et al., 2008; van de Vijver, Ridderinkhof, & Cohen, 2011). Similar to Cavanagh et al. (2010) we saw little if any evidence for elevated beta activity in the midfrontal region for either ERSP or ITC (see our Figure 2). Because both chance-based (e.g., this study) and learning tasks (e.g., Cavanagh et al. 2010) have been employed, the absence of a beta effect for reward in our study is probably not due to this factor.
