RESTING-STATE OSCILLATORY SIGNATURES OF SUCCESSFUL FEAR MEMORY CONSOLIDATION

Although individuals differ in their propensity to consolidate fear memories, the neural oscillatory mechanisms underlying these inter-individual differences remain poorly understood. The present study employed magnetoencephalography (MEG) to investigate differences in resting-state neural oscillations between individuals who do and do not successfully undergo fear memory consolidation.
34 healthy participants underwent fear conditioning where visual stimuli were paired with painful electrical stimulation, and fear responses were quantified using skin conductance responses (SCRs). Based on SCR indices, participants were categorized into "Consolidation Success" and "Failure" groups. Eyes-closed resting-state MEG was recorded for 5 minutes pre-conditioning and for 15 minutes post-conditioning, targeting the critical window for early memory stabilization. To identify consolidation-related changes, we reconstructed brain activity for 15,000 vertices using minimum norm estimation and compared the power spectral density between the pre- and post-conditioning sessions within each group using threshold-free cluster enhancement.
In the Success group, alpha-band power was significantly reduced in the post-conditioning session compared to the pre-conditioning baseline. This reduction was observed across widespread cortical regions, including the bilateral temporal regions, the right insular cortex, the right inferior frontal gyrus, and the right anterior cingulate cortex. These findings suggest that alpha-band power reductions across relatively widespread cortical regions contribute to fear memory consolidation, including key areas involved in salience and emotional processing, such as the temporal region, insular cortex, and anterior cingulate cortex.