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Abstract

Sensory motor rhythm (SMR) (12-15 Hz) originates in ventrobasal nuclei, and is related to the inhibition of afferent thalamic somatosensory information. According to recent findings of neurophysiological studies, SMR has a negative correlation to activity in the sensory motor area. Furthermore, SMR is associated with reduced external information input. Based on this evidence, it is possible that the reduction of SMR activity might be related to the concept of automaticity. However, studies have not examined the relationship between SMR neurofeedback training and precision sport performance. Therefore, this paper aimed to review neurophysiological and neurofeedback studies of SMR with hopes of formulating a possible relationship between SMR and optimal performance. Critical issues for neurofeedback studies were also included.
腦波感覺動作頻率在運動表現提升的應用 1
中文摘要 2
感覺動作頻率 (sensory motor rhythm, SMR) 是源於腹側基底核之 12-15Hz 之腦波,3
其活動與抑制身體感覺訊息傳入有關根據近年神經生理發現SMR 功率與感覺動作區4
的活動呈負相關且較高的 SMR 功率也造成外在訊息輸入的降低。因此SMR 活動似乎5
與動作自動化的概念相符。然而,在神經回饋訓練促進運動表現的相關文獻中,卻尚未6
出現以 SMR 為訓練指標之研究本篇論述性文章之目的在於回顧過去 SMR 神經生理及7
神經回饋相關研究,確立 SMR 腦波與較佳運動表現之關係,並提供未來神經回饋研究8
之相關建議。 9
關鍵字:自動化、較佳心理狀態、神經回饋、精準性運動 10
Abstract 11
Sensory Motor Rhythm (SMR; 12-15Hz) originates in ventrobasal nuclei, and is related to 12
the inhibition of afferent thalamic somatosensory information. According to recent 13
neurophysiological findings, SMR has a negative correlation to activity in the sensory motor 14
area. Furthermore, SMR is associated with reduced external information input. Based on this 15
evidence, it is possible to deduce that SMR activity might be related to the concept of 16
automaticity. However, studies have not examined the relationship between SMR 17
neurofeedback training and precision sport performance. As such, this paper aimed to review 18
neurophysiological and neurofeedback studies of SMR with hopes of formulating a possible 19
relationship between SMR and optimal performance. Critical issues for neurofeedback studies 20
were also included. 21
Key words: automaticity, optimal mental state, neurofeedback, precision sports. 22
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壹、前言 1
在高水平運動員當中,技能水準的差距往往相當些微,而影響最後表現的因素往往2
取決於心理狀態的調整 (Orlick, 2007)。尤其在精準性運動中,例如射擊、射箭、高爾3
夫球推桿與飛鏢投擲等,要求高度的協調與精細的動作控制,動作前的心理準備會影響4
到運動表現。且 Salazar et al. (1990) 也認為在精熟動作(skilled movement)執行前幾秒5
鐘的時間是個體調整其注意力或覺醒程度的最後階段,此階段的心理狀態對於表現具有6
關鍵的影響。瞭解這關鍵時刻運動員的心理狀態,將會幫助運動員發揮應有水準,而不7
至於求好心切導致壓力下失常 (Beilock, 2007)。上述概念與動作學習中自動化的概念相8
同,Fitts Posner (1967) 提出動作學習的三階段論,第一階段為認知期,其認為動作9
學習是由瞭解技能動作的開始,此階段強調的是對於認知取向問題的瞭解以及需要意識10
控制動作;第二階段為聯結期,此階段注重對於特定環境線索的覺察並將動作更加精11
化,是提升動作一致性且降低變異性的階段;最後一個階段為自動化階段,當得到相當12
經驗與經過大量練習後,動作技能可以不必經由意識控制而展現出來,而是以一種自動13
產生的形式將動作展演。因此,不管環境如何變化,將動作技能維持在自動化階段是很14
重要的,假如因無法持續投注適當的注意力而導致外在分心物介入動作模式,將會干預15
自動化的動作程式,表現也會因此受影響。總結上述,我們可瞭解精準性運動選手其表16
現前的心理狀態是影響表現的關鍵,不僅如此,注意力的適當投入更是讓表現維持自動17
化展現的一把鑰匙。 18
貳、腦波在運動表現研究上的應用 19
過去運動心理學領域對於注意力的測量可分為量表式和行為式 (洪聰敏, 1998),然20
,近年來以心生理學 (psychophysiology) 為基礎來測量注意力之研究數量漸漸成長。21
量表式是利用事後回溯的方式來瞭解當事者運動時的心智狀態以量表式測量注意力可1
能會因為過度主觀或是記憶落差而導致結果偏差;另一方,行為式的測量,例如2
應時間,其結果往往與注意力的關係較間接無法直接反應運動員當下的心智歷程。而3
屬於心生理工具的腦波 (electroencephalography, EEG)其擁有表現中記錄以及具有高時4
間解析度的優點可反應運動員當下的心智歷程因此可作為測量動作行為中之心理歷5
程訊息以及大腦如何整合動作控制的有效工具 (Hatfield & Hillman, 2001)。在過往的研6
究中腦波已經使用在測量自我配速運動動作執行前心理狀態的測量 (Crews & Landers, 7
1993; Loze, Collins, & Holmes, 2001) 8
精準性運動表現與腦波的關係在近幾年來已有一定的研究基礎,並發現多個動作執9
行前與較佳表現有關之腦波指標。高士竣、洪聰敏與黃崇儒 (2009) 回顧文獻後發現較10
佳精準性運動表現與一些準備動作期的腦波注意力指標有所關聯,包括左顳葉區 α 11
(T3 α) 增加,代表此區的活動減少,可能與減低與動作執行非相關的口語分析歷程有12
;枕葉中央皮質的 α (Oz α) 增加減少外在視覺訊息的回饋干擾;額葉中央區 (Fz) 13
與左顳葉區 (T3) 之間的相干性 (coherence) 下降代表動作區與語言分析的左腦皮質溝14
通減少,以減少注意力干擾;前額中線區的 θ波增加,與持續性的注意力以及更有效率15
的注意力分配有關Cz, C4, Fz 的事件關連去同步化 (event-related-desynchronization, ERD) 16
的振幅增加則與較好的動作預備程度有關。然而,上述較佳精準性運動的腦波指標除了17
Cz 位於動作皮質區以外其他電極位置與動作的關係似乎較為間接,且這些電極位置受18
到眨眼訊號的干擾也較嚴重,縱使眨眼訊號能藉由數學演算式將其從腦波訊號中移除,19
但其訊號可靠性仍不足與動作皮質區周圍的電極比較。因此,動作皮質區鄰近位置的腦20
波頻率與運動表現之關係應被進一步被探討。 21
叄、感覺動作頻率與運動表現的關係 22
回顧近年來有關動作皮質區鄰近區域的腦波研究,其最主要的發現首推 SMR 1
(sensory motor rhythm)SMR 是位於感覺動作區 12-15 Hz 的腦波頻率段,其功率大小與2
感覺動作區之活動呈負相關 (Sterman, 1996)。不僅如此,由於感覺動作區的腦波活動與3
精準性運動表現息息相關 (Babiloni et al., 2008),透過此區與動作的高相關性以及 SMR4
頻率的功能性意義,檢驗此頻率段在精準性動作執行表現中的活動是必要的。以下將從5
神經生理角度解釋SMR 與感覺動作區的關連並結合實際精準性運動中SMR 腦波功率活6
動之研究發現,來支持 SMR 功率與運動表現之研究必要性。 7
首先,Howe and Sterman (1972, 1973) 以神經生理的角度進行 SMR 的動物研究,發8
現在非活動但保持專注且警覺的行為中,身體感覺輸入的減少會促使腹側基底丘腦神經9
(Ventrobasal thalamic nuclei) 放電,SMR 便會產生。另外,對於人類動作與 SMR 10
研究也發現以視覺專注在刺激上的作業相較於動作作業在感覺動作皮質區有較高的 1111
15 Hz 頻率活動 (Mann, Sterman, & Kaiser, 1996)Sterman (1996) 也提出動作活動與抑12
SMR 活動有關,且會干擾知覺及訊息處理的整合。因此SMR 的活動可能與外在動13
覺的傳入呈現負向關係。而有關 SMR 活動與精準性運動表現的研究尚未被建立Cheng 14
et al. (2011) 比較飛鏢投擲專家與生手在出手前兩秒的 SMR 活動差異,發現專家選手在15
出手前兩秒的 SMR 功率顯著高於生手並維持穩定較高的趨勢,而生手則無顯著變化。16
意謂著專家選手在投擲飛鏢前其注意力不被外在動作訊息介入而影響其動作表現,而是17
以一種自動化的方式執行動作,以致於產生較高的 SMR 功率。而生手在投擲飛鏢前較18
低的 SMR 功率可能與學習一項新的動作技能時依賴外在訊息的回饋來執行動作有關,19
如此便會使感覺動作區不斷的處理外在動覺訊息,導致較高的感覺動作區活動,並伴隨20
著較低的 SMR 功率。基於上述研究證據,SMR 腦波活動與運動表現關係之密切並不亞21
於先前被建立之相關較佳表現腦波指標,其應用性應進一步被發展。不僅如此SMR 22
有排除外在動覺訊息干擾之特徵,適合應用在自動化動作執行前的注意力測量。 1
肆、SMR 神經回饋訓練與認知活動之關係 2
Kamiya (1969) 發現人類可以透過學習而去控制腦波,因此學習自我控制腦波活動3
的方式被用在許多不能以藥物有效治療的大腦功能失調病症,例如:癲癇 (Sterman, 4
2000)自閉症 (Kouijzer, de Moor, Gerrits, Congedo, & van Schie, 2009) 與注意力缺乏症候5
(ADHD) (Kropotov et al., 2005)神經回饋訓練是經由紀錄個體腦波活動並即時利用腦6
波活動為回饋訊息,以聽覺或視覺的方式回饋給個體,使得個體能夠瞭解自身的心理狀7
態並進一步學習控制腦波活動,其訓練的效果是基於特定腦波特徵會連結特定行為表現8
的假定上 (Vernon, 2005)除了臨床的證據外神經回饋訓練也被發現到能提升健康者對9
大腦皮質活動的控制能力進而提升注意力 (Egner & Gruzelier, 2001; Hanslmayr, Sauseng, 10
Doppelmayr, Schabus, & Klimesch, 2005)。不僅如此,神經生理方面的研究證據顯示神經11
回饋訓練可增強神經連結的強度 (Ros, Munneke, Ruge, Gruzelier, & Rothwell, 2010),因12
支持了神經回饋訓練是一種可經由學習而成為自身運用之心理技能。 13
過去研究已經初步證實操弄 SMR 活動與認知表現之間有適度的關聯,較高的 SMR14
與注意力的提升有關。Egner and Gruzelier (2001) 以藝術學院的學生為對象,探討 SMR15
β1神經回饋訓練對對於持續度表現測驗 (Continuous Performance Test, CPT) 的影響。16
結果發現 SMR 訓練組隨著訓練次數增加其誤判錯誤會越來越少,且兩組在訓練後其前17
額葉、中央區及頂葉區的 P300b 振幅也顯著增加,表示 SMR 活動的增加對於衝動性的18
抑制是有關連的,而 P300b 振幅與工作記憶中對於更新環境相關訊息刺激的神經活動提19
升有關 (Donchin & Coles, 1988),代SMR 神經回饋訓練能有效促進注意力提升Egner 20
and Gruzelier (2004) 在多相性注意力測驗中 (Test of Variables of Attention, TOVA) 也發現21
SMR 神經回饋組在訓練後其反應時間變異和遺漏錯誤顯著降低並伴隨著知覺敏感度的1
提升。綜合上述,神經回饋訓練不僅可改善失調的大腦功能性,對於注意力的促進也有2
效果。基於 SMR 腦波活動與注意力的關係,對於將此頻率段活動應用於促進運動表現3
之訓練指標,運用 SMR 做為神經回饋訓練之腦波指標,嘗試來增進運動表現是具有一4
定程度之可行性。 5
伍、未來研究方向 6
針對上述的研究發現,有關 SMR 神經回饋訓練的議題值得再進一步探討。首先,7
有關於訓練位置的大腦功能性改變是否與外顯的行為改變呈現對價關係,亦或是該訓練8
位置的神經回饋訓練改變了某大腦迴路進而影響了行為呢?Egner and Gruzelier (2001) 9
發現 SMR 神經回饋訓練後縱使能使參與者的注意力表現提升,然而,與注意力密切相10
關的 P300b 振幅卻在前額區、中央區及頂葉區增加,可能代表注意力表現的提升並不能11
完全歸納於 SMR 神經回饋的結果,其餘腦區的功能性改變可能也會導致注意力表現的12
促進。縱使過去研究精準性運動與腦波指標之關係得到充分的證據 (Crews & Landers, 13
1993; Doppelmayr, Finkenzeller, & Sauseng, 2008; Kerick, et al., 2001; Loze, et al., 2001)但是14
單一的腦波指標改變是否就足以造成運動表現之差異,這個議題的解決方法可採用訓練15
前後多頻道腦波儀的電極位置比較,以利找出受到訓練所影響之腦區;亦可尋求神經造16
影工具的協助,以大腦結構之變化來推論造成運動表現提升的生理機制。其次,需要控17
制存在於神經回饋訓練中的安慰劑效應 (placebo effect),安慰劑效應指病人或實驗參與18
者雖然獲得無效的治療,但卻「預期」或「相信」療效的存在,而讓病人或實驗參與者19
的病狀獲得舒緩的現象 (Gensini, Conti, & Conti, 2005)。其作用原理可能來自受試者期望20
效應、制約反應和暗示的力量,因這些心理層面的差異會改變情緒、行為以及生理的運21
作,甚至會反轉既定效果。Hammond (2011) 回顧了過去有關神經回饋的與大腦生理機22
制轉變的研究,提到對於療效的正向預期會產生與真實療效相異的腦部活動 (Scott et al., 1
2008)換句話說,實驗參與者除了對於安慰劑效應所產生的療效有別於真實療效之外,2
其腦部活動的差異也會造成研究者觀察的偏差。因此,為了確保實驗之內在效度,設計3
一個排除造成混淆實驗觀察變項之研究設計是必要的。不僅如此,研究者與實驗參與者4
之間的互動也會造成不同程度上的安慰劑效應,諸如對於病人表示關心、表現出認同的5
瞭解與親切、頻率高的眼神接觸、展現出自信、透露出有能力且信任等 (Kaptchuk et al., 6
2008)因此,在神經回饋訓練的過程中,建議以較少的研究者實施訓練以利排除人際互7
動所造成的影響。除此之外,實驗指導語的應答流程及用字譴詞也應予以標準化,以排8
除不必要的誤差。 9
相對於傳統的心理技能訓練,神經回饋訓練以一種即時以及客觀的方式來幫助運動10
員瞭解自身的心理狀態,進而使運動員學習保持腦波活動於特定的功率範圍內以促進運11
動表現。過往的研究中尚未發現以 SMR 腦波做為神經回饋訓練指標,然而,此頻率段12
與排除外在動覺傳入的關係已被確立,相信與動作表現的關係非常緊密。不僅如此,感13
覺動作區相較於其他精準性運動指標之電極位置是離眼睛較遠的,其受眼球肌電的影響14
較小,應可擷取到較不受偽訊污染的訊號,也是本篇文章推薦以 SMR 作為未來相關研15
究的原因。最後,神經回饋中易造成實驗上的安慰劑效應,在未來研究時應特別謹慎,16
避免實驗的內在效度降低。 17
18
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高士竣、黃崇儒、洪聰敏 2009。較佳精準運動表現中專注的腦波特徵。中華體育季22
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