Contrasts which compare successful recall events to “deliberation” or “baseline” intervals in which no retrieval occurs [43] are similarly influenced by non-mnemonic factors. A subject’s disengagement from the task, or distraction with something else, could easily result in a lower rate of recall during that period. Therefore, a comparison of successful retrieval to such baseline intervals may not merely reflect cognitive processes related to memory retrieval. It remains therefore unclear, whether theta power decreases observed using this contrast [43,46,48,51,57] are linked to associative memory processes or the mentioned confounds.
