Does Theta Synchronicity of Sensory Information Enhance Associative Memory? Replicating the Theta-Induced Memory Enhancement Effect

Poster Session E - Monday, March 9, 2026, 2:30 – 4:30 pm PDT, Fairview/Kitsilano Ballrooms

Fatih Serin¹ (fatihsering@gmail.com), Danying Wang², Matthew Davis¹, Richard Henson^1,3; ¹MRC Cognition and Brain Sciences Unit, University of Cambridge, ²Institute of Cognitive Neuroscience, University College London, ³Department of Psychiatry, University of Cambridge

The binding of information from different sensory sources is critical for associative memory. Previous animal research suggested that the timing of theta oscillations in the hippocampus is crucial for long-term potentiation, which underlies associative memory. Studies with humans showed correlations between theta oscillations in the medial temporal lobe and episodic memory. Clouter et al. (2017) directly investigated this link by modulating the intensity of the luminance and the sound of the video clips so that they ‘flickered’ at certain frequencies and with varying synchronicity between the visual and auditory streams. Better memory was observed for the synchronous theta (4Hz) flickering compared with no-flicker, asynchronous theta, or synchronous alpha and delta flickering. This effect –the theta-induced memory enhancement (TIME) effect – is consistent with the importance of theta synchronicity for long-term potentiation. Electroencephalography data showed that synchronicity was achieved in neuronal oscillations. The theoretical importance, large effect size, and applicability to enhance real-world memory mean that replicating the TIME effect would be highly valuable. The present study aimed to replicate the key differences among synchronous theta, asynchronous theta, synchronous delta, and no-flicker conditions while addressing alternative explanations. Across two experiments (one registered report, one preregistered), we find no evidence of improved memory for theta synchronicity in any of the comparisons. MEG data from the first experiment suggested that the modulation manipulations worked as intended. We discuss explanations for the null results and provide a meta-analysis of TIME. Based on these findings, we suggest a reinterpretation of TIME to accommodate these non-replications.

Topic Area: LONG-TERM MEMORY: Episodic