The sleep spindle refractory period segments memory reactivation events across time
James Antony1, Luis Piloto1, Margaret Wang1, Paula Pacheco1, Kenneth Norman1, Ken Paller2; 1Princeton University, 2Northwestern University
The stability of long-term memories is enhanced during sleep. Although the specific role of thalamocortical sleep spindles in memory function is poorly understood, correlative evidence has linked spindles with memory replay. Here, we show that spindles increased shortly after sound cues presented during sleep to promote replay. Furthermore, spindles after cues were associated with better memory, but spindles shortly before cues predicted worse memory. We hypothesized that memory replay was less likely when cues occurred within the spindle refractory period. We thus tracked spindles in real-time and presented cues inside or outside the presumptive refractory period; memory was superior in the latter case. Our findings provide new evidence for how spindles segment time into memory reactivation events and reactivation blinks – when spindles are refractory.
Topic Area: LONG-TERM MEMORY: Episodic