研究目的 失眠的過度激發是目前最廣為接受的失眠病因之一。無論在生理、認知、行為三不同層面上，多可觀察到失眠者有身心過度激發的狀態。根據失眠三因子模式，不同失眠病程階段，影響過度激發的背後成因有所差異。在慢性失眠部分，過 去累積了相當多的實證研究證實其過度激發的現象，但尚未進入慢性病程前之過度激發相關機轉，仍有待研究進一步探討。本研究嘗試以橫斷式的研究方法，並依據過去失眠病因發展推導，選擇從壓力反應特性 (包含壓力操弄後的壓力反應強度和 消退速度)、注意力偏誤 (包含警覺性注意力和注意力移除困難)、與睡前的睡眠監控行為三個面向切入，探討不同病程階段個體過度激發的背後機轉，並進一步檢驗上述之差異是否可用以預測在壓力操弄情境下，不同病程個體睡前的激發反應變化，藉此檢驗失眠病程發展之病因假說，並希望未來可據此發展有效之失眠防治與介入策略。 研究方法 本研究共計招募受試者 58 人，年齡介於 24-48 歲，包含符合 ICSD-3 慢性失眠者 18 人，以及以壓力下失眠反應量表( Ford Insomnia Response to Stress Test; FIRST)區分出急性失眠高危險組 19 人與低危險組 21 人。每位受試者皆需到睡眠實驗室進行兩階段的實驗，第一階段包含晤談評估、問卷填答、壓力反應的生理測量(以指溫與膚電為指標)、與包含威脅與睡眠刺激之點偵測注意力作業，之後需配戴腕錶與記錄睡眠日誌配合充足且規律作息一週後，再到睡眠實驗室進行第二階段的評量，包含睡前 2 小時、1 小時、關燈前生理指標 (指溫、膚電) 與腦波的測量和主觀身心激發狀態 (Pre-Sleep Arousal Scale, 簡稱 PSAS) 評量，於睡前填寫睡眠相關監測指標 (Sleep Associated Monitoring Index，簡稱 SAMI)，並完成一晚的 PSG 測量以排除其他睡眠相關疾患。 研究結果 首先，以單因子變異數分析比較不同組別間在壓力反應與回復和二因子變異數分析注意力警覺/移除困難指標的差異。在壓力生理反應表現上，慢性失眠組與高危險組在接受壓力操弄後的激發消退時間較低危險組來得長。在注意力層面，高危險組對壓力(威脅圖片) 刺激有顯著的警覺與移除困難注意力偏誤，慢性失眠組則是對睡眠刺激有顯著的移除困難注意力偏誤。在行為層面，慢性失眠組與高危險組睡前的注意力監控行為 (包含監測自身身體感覺訊息是否與入睡狀態不一致、鬧鐘 時間、環境) 均顯著較低危險組來得多。再者，以皮爾森相關探討注意力偏誤與睡前激發反應之關聯性，結果顯示高危險組的注意力偏誤現象與睡前高頻腦波與主觀生理激發的降幅呈現顯著負相關; 而慢性失眠組的注意力偏誤指標卻與膚電、主觀認知激發的降幅呈顯著正相關。 結論 本研究結果支持不同失眠病程背後的過度激發影響機制有所差異，生理層面較慢的激發消退能力與對壓力源的認知偏誤的前置因子，可能為急性失眠者易受日常壓力源誘發睡眠困擾之原因；而影響慢性失眠族群的持續因子主要在於其將睡眠視 為壓力源的認知歷程與行為轉變。此外，研究更進一步發現兩組分別對於壓力與睡眠的注意力轉移困難，使其在覺察壓力後易持續表現出過度激發現象。本研究結果除支持失眠過度激發理論之外，更釐清不同階段失眠的認知歷程的機制，並彰顯不 同失眠病程介入策略應有所差異，和急性失眠高危險族群及早介入預防之重要性。 / Introduction Hyperarousal has been recognized to be a major etiological factor of chronic insomnia. Cumulated research evidences have demonstrated that chronic insomnia patients are hyperaroused in somatic, cognitive, and behavioral aspects. According to Spielman’s 3P Model of Insomnia, there were different factors are involved at different points during the course of insomnia. However, there are seldom study to investigate the difference mechanism of hyperarousal in the course of the development of insomnia. The present study used cross-sectional design to compare the difference of good sleeper (low sleep vulnerability, LV), acute insomnia (high sleep vulnerability, HV), and chronic insomnia (CI) in stress reaction (eg. reactivity and recovery), attentional bias (eg. vigilance and disengagement), and sleep associated monitoring behaviors to investigate the underlying mechanism of hyperarousal. Furthermore, the study examined the correlation between attentional bias indices and subsequent pre-sleep arousal to investigate the impact of attentional bias on sleep in different groups. Method The present study recruited fifty-eight subjects, aged between 24-48. They included eighteen chronic insomniacs (CI) diagnosed ICSD-3, nineteen healthy individuals scoring high (HV) and twenty-one healthy individuals scoring low (LV) on the Ford Insomnia Response to Stress Test (FIRST). All subjects visited sleep lab twice. During the first visit, the subjects filled in a package of questionnaires, and went through psychophysiological recording (including) of stress reaction, and a visual dot-probe task. They then were required to keep a sleep log and wear actigraphy at home for one-week to make sure they followed a regular sleep schedule. During the second visit, subjects went through a pre-sleep physiological recording (including peripheral temperature, skin conductance, and EEG) and filled in two questionnaires (Pre Sleep Arousal Scale [PSAS] and Sleep Associated Monitoring Index[SAMI]) at three time points and had a PSG recording to screen for sleep disorders. Result One-way ANOVAs were conducted to compare the differences of stress reaction/recovery among three groups. Two-way ANOVAs were used to compare the differences in attentional bias (vigilance/ disengagement) of threatening and sleep-related stimulus among three groups. In stress related physiological activity, CI and HV showed slower recovery rate than LV. Considering attentional bias, HV had significant vigilance and disengagement bias to threatening pictures, and CI had significant disengagement bias to sleep-related pictures. CI and HV also showed more prevalent sleep-associated monitoring behaviors than LV. Furthermore, Spearman’s correlation was used to examine the association between attentional bias and pre-sleep arousal. The result shows the attentional bias of HV had negative correlation with reduction of high frequency EEG and somatic sub-score on the PSAS. In contrast to our prediction, CI showed positive correlation between decrease of skin conductance and the cognitive sub-score on the PSAS. Conclusion The study showed that stress recovery ability and stress-related attentional bias were the major differences between individuals with low and high sleep vulnerability, indicating that increased information processing to threats and stress-related stimulus as well as decreased recovery ability of autonomic arousal in reacting to stress may predisposed an individual to stress-related sleep disturbances. On the other hand, the attention shift from threat toward sleep can differentiate chronic insomnia from those individual with frequent acute insomnia. Moreover, the difficulty in disengagement from sleep-related stimulus, rather the vigilance, might explain the cause of hyperarousal that perpetuate insomnia. The results support the transition of arousal from general treat to sleep-related stimulus in the development of chronic insomnia. The study not only further the understanding of the etiological mechanism of insomnia, but also imply that different strategies should be applied in the treatment of acute and chronic insomnia. It also highlights the importance of preventive intervention for individuals with high sleep vulnerability