Table 1.

Sleep studies with closed-loop feedback systems.

Literature	Stimulus Type	Control Parameters	Behavioral Effects
Mouze-Amady et al. [49]	Acoustic	White noise stimulation at REM detection	Prolonged REM duration
Ngo et al. [36,37]	Acoustic	Pink noise at up-state SW	Declarative memory improvement
Besedovsky et al. [52]	Acoustic	Pink noise at up-state SW	Regulating immune-supportive function
Santostasi et al. [38] Ong et al. [39,75] Papalambros et al. [40] Leminen et al. [41]	Acoustic	Phase-locked pink noise on SO	Declarative memory improvement
Bergmann et al. [45]	TMS	TMS at up-state SW	-
Lustenberger et al. [46]	tACS	spindle-like tACS at spindle activity	Procedural memory improvement
Henin et al. [72]	Acoustic	Pink noise at up-state SW	-
Choi et al. [64]	Acoustic	Pink noise at spindle activity	Procedural memory improvement
Robinson et al. [53]	tACS	SW-like tACS in phase with SW oscillations	Improved subjective sleep quality
Ketz et al. [54]	tACS	SW-like tACS in phase with SW oscillations	Improved long-term memory generalization
Pilly et al. [74]	tDCS & tACS	TMR at up-state SW	Targeted memory improvement
Choi et al. [42]	Vibration	Vibration stimuli with a relative heart rate change	Stabilized the autonomic nervous system
Antony et al. [65]	Acoustic	TMR after spindle activity	Improved declarative memory
Ngo et al. [66]	Acoustic	Spindle-frequency AM-WN stimulation at up-state SW	-
Fattinger et al. [67]	Acoustic	Spindle-frequency AM-WN stimulation at up-state SW	-