Here, we seek to reconcile the conflicting literature regarding theta’s role in human episodic memory. First, we will review electrophysiological studies which report increases, decreases, or mixed effects of theta activity during episodic memory tasks. In doing so, we will address how the recording methods as well as particular experimental and analytical methods may be responsible for reported increases or decreases in theta power during successful memory encoding and retrieval. We specifically highlight how contrasts that compare activity for remembered and forgotten stimuli, though commonly used in the literature, inherently confound associational memory processes with a diverse array of other cognitive functions that support successful task completion. These confounds make it difficult to interpret the results and are a key factor behind the conflicting findings. To that end, we will offer a defense for the prevailing theta hypothesis, explaining how the existing body of literature in spatial and episodic domains supports the idea that the theta rhythm underlies associative processing in the brain.
