The ability to adapt behavior to situational changes is a central aspect of human cognitive control or executive functioning. Through trial and error, individuals can then infer the correct rules and adapt their behavior or response strategy accordingly. Prior research has mostly linked feedback-related negativity (FRN) and theta band activity to feedback-related behavioral adaptation. Based on neurophysiological and cognitive science considerations and using an extended sample of N = 226 healthy individuals, we asked whether other neural activities (i.e., aperiodic activity and alpha band activity) are important elements enabling adaptive behavior. In an EEG-based Wisconsin Card Sorting Task, we examined the chain of processes triggered by the feedback presentation up to the next trial to see how people adjusted. Our findings highlight the distinctive role of alpha band activity, particularly after adjusting for aperiodic activity. Alpha activity, modulated throughout feedback stages, increased following negative feedback and strongly predicted improved performance in subsequent trials. This predictive relationship emerged after controlling for aperiodic activity, revealing alpha's role in inhibitory gating and categorization processes critical for adaptive behavior, especially under conditions requiring suppression of task-irrelevant information. Although not directly predictive of performance, aperiodic activity influenced alpha processes during feedback, suggesting a metacontrol mechanism that supports feedback-related behavioral adaptation. These findings integrate alpha and aperiodic activity with established FRN and theta band processes, offering novel insights into the neural basis of behavioral adaptation.