Optimizing automated phase-targeted auditory stimulation protocols for procedural memory consolidation during sleep...

Area of Science:

• Neuroscience
• Sleep Science
• Cognitive Psychology

Background:

• Up-phase-targeted auditory stimulation (up-PTAS) enhances memory consolidation during sleep by modulating brain oscillations.
• Current up-PTAS protocols vary, hindering clinical translation and understanding of behavioral effects.
• Automated, naturalistic protocols are needed for wider application.

Purpose of the Study:

• To compare two up-PTAS protocols with varied interstimulus intervals (ISIs) for their effect on overnight memory consolidation.
• To assess the feasibility of mobile, at-home up-PTAS with app-based behavioral tasks.
• To explore electrophysiological correlates of behavioral responses to up-PTAS.

Main Methods:

• Participants underwent two up-PTAS protocols with systematic variations in ISIs during sleep at home.
• A mobile PTAS device and an app-based finger-tapping task were used to measure memory consolidation.
• Electrophysiological responses (K-complexes, spindles) were analyzed.

Main Results:

• Both protocols were well-tolerated with high adherence.
• Fewer stimuli with longer ISIs (>1.25s) enhanced finger-tapping sequence consolidation more than more stimuli with shorter ISIs.
• Longer ISIs were associated with increased K-complex likelihood, spindle power, and positive behavioral outcomes.

Conclusions:

• Mobile, at-home up-PTAS with app-based tasks is feasible in healthy individuals.
• Optimizing ISI duration is crucial for enhancing memory consolidation via up-PTAS.
• Findings inform the development of more effective memory enhancement protocols using targeted sleep stimulation.