Oscillations and aperiodic activity: Evidence for dynamic changes in both during memory encoding

EEG studies show that human brain activity involves rhythmic oscillations linked to various cognitive processes and diseases. Recent research, however, highlights the importance of non-oscillatory, aperiodic neural activity, which is connected to the balance of neuronal excitatory and inhibitory signaling. Traditional analysis methods often mix up oscillations and aperiodic activity, obscuring their distinct roles in perception, cognition, and disease. This study reanalyzes intracranial human EEG data from Fellner et al., 2019, using techniques to separately analyze oscillations and aperiodic activity. The findings reveal that human memory encoding involves rapid co-modulation of both oscillatory and aperiodic activity, suggesting that these two processes, while independent, are interconnected and play significant roles in human cognition.