International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8575, Japan.
The Japan Society for the Promotion of Science (JSPS) Foreign Researcher, Tokyo, Japan.
Sci Rep. 2024 Oct 30;14(1):26062. doi: 10.1038/s41598-024-76059-9.
Binaural beats can entrain neural oscillations and modulate behavioral states. However, the effect of binaural beats, particularly those with slow frequencies (< 1 Hz), on sleep remains poorly understood. We hypothesized that 0.25-Hz beats can entrain neural oscillations and enhance slow-wave sleep by shortening its latency or increasing its duration. To investigate this, we included 12 healthy participants (six women; mean age, 25.4 ± 2.6 years) who underwent four 90-min afternoon nap sessions, comprising a sham condition (without acoustic stimulation) and three binaural-beat conditions (0, 0.25, or 1 Hz) with a 250-Hz carrier tone. The acoustic stimuli, delivered through earphones, were sustained throughout the 90-min nap period. Both N2- and N3- latencies were shorter in the 0.25-Hz binaural beats condition than in the sham condition. We observed no significant results regarding neural entrainment at slow frequencies, such as 0.25 and 1 Hz, and the modulation of sleep oscillations, including delta and sigma activity, by binaural beats. In conclusion, this study demonstrated the potential of binaural beats at slow frequencies, specifically 0.25 Hz, for inducing slow-wave sleep in generally healthy populations.
双耳节拍可以引发神经振荡并调节行为状态。然而，双耳节拍（尤其是频率较慢的，<1 Hz）对睡眠的影响仍知之甚少。我们假设 0.25 Hz 的节拍可以通过缩短潜伏期或增加其持续时间来引发神经振荡并增强慢波睡眠。为了研究这一点，我们纳入了 12 名健康参与者（6 名女性；平均年龄 25.4 ± 2.6 岁），他们进行了 4 次 90 分钟的下午午睡，包括假条件（无声学刺激）和 3 次双耳节拍条件（0、0.25 或 1 Hz），载波频率为 250 Hz。通过耳机传递的声学刺激在 90 分钟的午睡期间持续。与假条件相比，0.25 Hz 双耳节拍条件下的 N2 和 N3 潜伏期更短。我们没有观察到与慢频率（如 0.25 和 1 Hz）的神经同步以及双耳节拍对睡眠振荡（包括 delta 和 sigma 活动）的调制相关的显著结果。总之，这项研究表明，低频（特别是 0.25 Hz）的双耳节拍有可能在一般健康人群中诱发慢波睡眠。
