Chen Hui-Ya, Chen Li-Yuan, Lou Shu-Zon, Lin Chun-Ling
Department of Adapted Physical Education, National Taiwan Sport University, Taoyuan, Taiwan.
Department of Physical Therapy, Chung Shan Medical University, Taichung, Taiwan.
PLoS One. 2025 Apr 9;20(4):e0320926. doi: 10.1371/journal.pone.0320926. eCollection 2025.
Lowered arousal state after napping may lead to poorer standing balance and the need to recalibrate the sensory organization system. This study aimed to examine the changes in postural sway and sensory associated cortical activities immediately after waking from a nap. A convenience sample of young adults (7 males and 5 females, 21.0 ± 2.3 yr.) was recruited. Before and after a 50-min lying-down nap, participants were asked to stand quietly with eyes open/closed on a firm/foam surface, and electroencephalography (EEG) in theta, alpha, beta, and gamma bands in sensory association areas was recorded. All participants self-reported that they fell asleep during the 50-min period provisioned for nap (Karolinska Napiness Scale before nap 4.2 ± 1.1, after nap 5.7 ± 0.8). The average time taken to finish data collection after waking the participants was 19.0 ± 4.0 minutes. The results showed less postural sway (t11 = 2.726, p = 0.02) and increased frequency of postural sway (t11 = -3.339, p = 0.007) after nap in the eyes-open firm-surface condition. The EEG results revealed decreased activity in the alpha (F1,9 = 15.540, p = 0.003) and gamma (F1,9 = 6.626, p = 0.030) bands in the right parietal area after nap, and increased beta power in the left occipital area (Z = -2.241, p = 0.025). In conclusion, after waking from a nap, healthy adults show increased changes in direction of postural sway which is effective in decreasing postural sway in eyes-open firm-surface condition. Even in healthy adults without worsen postural performance after nap, the EEG results suggested a decrease of efficacy in dealing with sensory challenges within twenty minutes post napping. This study contributes to the understanding of the mechanisms underlying changes in balance control after napping, which might help fall prevention programs for the elderly.
午睡后唤醒状态降低可能导致站立平衡能力下降，以及需要重新校准感觉组织系统。本研究旨在探讨午睡醒来后即刻姿势摆动和感觉相关皮层活动的变化。招募了一组方便样本的年轻成年人（7名男性和5名女性，21.0±2.3岁）。在进行50分钟的躺卧午睡前后，要求参与者在坚实/泡沫表面睁眼/闭眼安静站立，并记录感觉关联区域中θ、α、β和γ频段的脑电图（EEG）。所有参与者均自我报告在规定的50分钟午睡期间入睡（午睡前卡罗林斯卡嗜睡量表为4.2±1.1，午睡后为5.7±0.8）。唤醒参与者后完成数据收集的平均时间为19.0±4.0分钟。结果显示，在睁眼坚实表面条件下，午睡后姿势摆动减少（t11 = 2.726，p = 0.02），姿势摆动频率增加（t11 = -3.339，p = 0.007）。脑电图结果显示，午睡后右侧顶叶区域的α频段（F1,9 = 15.540，p = 0.003）和γ频段（F1,9 = 6.626，p = 0.030）活动降低，左侧枕叶区域的β功率增加（Z = -2.241，p = 0.025）。总之，午睡醒来后，健康成年人姿势摆动方向的变化增加，这在睁眼坚实表面条件下有效减少了姿势摆动。即使在健康成年人午睡后姿势表现未恶化的情况下，脑电图结果也表明午睡后20分钟内应对感觉挑战的效能降低。本研究有助于理解午睡后平衡控制变化的潜在机制，这可能有助于老年人的跌倒预防计划。
