EEG biomarkers of free recall

•Increased theta (4–8 Hz), decreased alpha (8–20 Hz), and increased gamma (40–128 Hz) power appear in the moments immediately preceding spontaneous recall of context-dependent, long-term memories.•This pattern of increased theta, decreased alpha, increased gamma appears more strongly when recalling memories after a delay of one or more days than when recalling memories after just a few seconds. This comparison between immediate and delayed recall helps to minimize the contribution of motor-related EEG signals that may accompany vocal recall.•These spectral biomarkers of memory retrieval preceding spontaneous recall contributes to an emerging body of evidence demonstrating the utility of non-invasive recording methods for decoding cognitive states.