Insights on auditory closed-loop stimulation targeting sleep spindles in slow oscillation up-states

Whole-Night Continuous Rocking Entrains Spontaneous Neural Oscillations with Benefits for Sleep and Memory

“…Moreover, sensory stimulations may disrupt or enhance sleep: just think of the traffic noise that keeps us awake, whereas the gentle sway of a hammock may soothe us to sleep. We previously corroborated the latter observation by showing that a continuous rocking stimulation (lateral movement at 0.25 Hz) applied during a 45-min nap shortened sleep latency, increased time spent in non-rapid eye movement (NREM) sleep, and enhanced sleep spindles (11)(12)(13)(14)(15) Hz) [7]. Several lines of evidence support the idea that sensory stimulations foster sleep oscillations, whether stimuli are presented at a specific phase of the ongoing oscillatory activity (i.e., using closed-loop stimulations [8][9][10][11]), or whether the stimulation is applied in a rhythmic pattern [7,[12][13][14].…”

“…We previously corroborated the latter observation by showing that a continuous rocking stimulation (lateral movement at 0.25 Hz) applied during a 45-min nap shortened sleep latency, increased time spent in non-rapid eye movement (NREM) sleep, and enhanced sleep spindles (11)(12)(13)(14)(15) Hz) [7]. Several lines of evidence support the idea that sensory stimulations foster sleep oscillations, whether stimuli are presented at a specific phase of the ongoing oscillatory activity (i.e., using closed-loop stimulations [8][9][10][11]), or whether the stimulation is applied in a rhythmic pattern [7,[12][13][14]. Such entrainment of ongoing brain oscillations by an external drive is thought to involve a mechanism of neural phase reset reflecting the reorganization of the ongoing brain oscillations, specifically when applied in pulsed stimulation [8][9][10][11][12][13]15].…”

“…Several lines of evidence support the idea that sensory stimulations foster sleep oscillations, whether stimuli are presented at a specific phase of the ongoing oscillatory activity (i.e., using closed-loop stimulations [8][9][10][11]), or whether the stimulation is applied in a rhythmic pattern [7,[12][13][14]. Such entrainment of ongoing brain oscillations by an external drive is thought to involve a mechanism of neural phase reset reflecting the reorganization of the ongoing brain oscillations, specifically when applied in pulsed stimulation [8][9][10][11][12][13]15]. In contrast, continuous cyclic stimulation [7,16] might also entrain endogenous brain rhythms by synchronizing to the stream of external events without imposing a phase-reset mechanism [15].…”

Modulating Human Memory via Entrainment of Brain Oscillations

“…These effects were replicated in older adults [28] and in young healthy students taking a nap [29]. However, auditory stimulation during sleep in general elicits slow oscillations and spindles [25,30], which makes it difficult to ascertain whether changes in memory performance were due to changes in slow wave or spindle activity. Another issue is that these studies could not disentangle direct effects of stimulation on the neural processes of memory consolidation, from an indirect improvement of conditions that are conducive for memory consolidation (e.g.…”

Pathway-Dependent Regulation of Sleep Dynamics in a Network Model of the Sleep–Wake Cycle

“…To address this issue, it would be interesting to connect the modeled sleep-wake regulating circuit to cortical circuits and muscle units, through which the state of the system can be defined based on the activity of the cortical circuits or muscle units as in biological experiments. This direction will become an important topic to better understand how subcortical sleep-regulating circuits and cortical circuits interact with each other across the sleep-wake cycle and how recent closed-loop stimulation approaches affect neural circuit dynamics as well as connectivity (Marshall et al, 2006;Ngo et al, 2019).…”