System identification for sleep-mediated, stimulation-enhanced memory consolidation

Kyle Q. Lepage, Sujith Vijayan

Abstract: Memory consolidation is part of the process by which memories are formed in the brain, a process which confers improved memory retention and recall. Sleep enhances memory consolidation. Electrical stimulation or the presentation of sensory stimuli during sleep can further boost sleep-related memory consolidation. The enhancement of naturally occurring sleep oscillations, namely sleep spindles and slow-wave oscillations, appears critical for stimulation-based improvement of sleep-related memory consolidation. Thus, the memory benefits of sleep may benefit from a stimulation paradigm that optimally augments both slow-waves and spindles. In this work, by focusing on stimulated sleep-spindle prevalence, a first step towards this broader goal is taken. Specifically, this work introduces an adaptive experimental design paradigm which reduces the problem dimension through the use of a library of stimuli in a fashion directly motivated by experimental questions, and then employs an approximate 1-step D-optimal adaptive experimental design based upon this library for the purpose of system identification. This work provides methodological advancements stepping towards the larger system identification goal within the framework of a neural mass model that can generate neural activity that is faithful to the characteristics of non-rapid eye movement sleep, including sleep spindles and slow-wave oscillations.