Auditory-evoked changes in slow oscillations and spindles correlate with memory consolidation in children with epilepsy and controls

Objective: We investigated the effects of auditory stimulation during sleep on slow oscillations (SOs), SO-spindle complexes, and sleep-dependent memory consolidation in children with Rolandic Epilepsy (RE) and controls. Methods: Participants completed two nap visits with auditory or sham stimulation. SOs and SO-spindle complexes rates were measured offline using validated detectors. Sleep-dependent memory consolidation was assessed using the motor sequence typing task. Results: Auditory stimulation evoked SOs and SO-spindle complexes with maximal effect over frontal electrodes. Compared to sham, stimulation of background activity increased SOs (29.8 %, p < 0.001) and SO-spindle complexes (16.8 %, p < 0.001); stimulation of an ongoing SO upstate maximally evoked SOs (51.3 % increase, p < 0.001) and SO-spindle complexes (32.3 % increase, p < 0.001). Changes in frontal SO (1.9 % improvement per increase in SO/min; p < 0.001) and SO-spindle complexes (9.5 % improvement per increase in SO-spindle/min; p = 0.007) event rates due to auditory stimulation positively predicted changes in sleep-dependent memory consolidation. Conclusion: Auditory stimulation reliably modulates sleep oscillations when delivered on background activity and during the upstate of SOs. As increased event rates improve memory consolidation, stimulation paradigms to increase SO and SO-spindle complex rates are required to enhance memory. Significance: Auditory stimulation paradigms that increase SO and SO-spindle complex rates may enhance sleep-dependent memory consolidation.