Figure 4.

Automatic acoustic stimulation system. (A) Overview of the real-time stimulus presentation system. The scoring and phase tracking were carried out on a running 30 s buffer which was updated at 50 Hz. Scoring was performed using the client–server architecture every second. When conditions based on phase of the EEG wave and sleep stage were satisfied, an auditory stimulus was presented. (B) Average event-related potentials stimulus locked to the first auditory stimulus for a representative participant, who underwent a stim and a sham session. Sham refers to the control condition where phase tracking was carried out but without auditory stimulation. Both sessions were separated by a week.