心臟節律與音樂同步

作者：Pauline Anderson  
出處：WebMD醫學新聞

　　June 30, 2009 — 根據一篇新研究，音樂，特別是漸強、音量逐漸加大的片段，可以引導年輕人出現同步的心血管與呼吸反應，不論是否為音樂家。
　　
　　主要作者、義大利Pavia大學內科教授Luciano Bernardi醫師表示，已知音樂可以誘發強烈的正面或負面情緒，但是這篇新研究顯示，音樂與無意識的生理反應也有關係。
　　
　　Bernardi醫師在訪問中表示，這或許是首次，指出音樂力學和心血管系統之間有連續的互動，而不論有無有意識的情感。
　　
　　他指出，這些發現對於使用音樂作為治療工具有潛在影響。他表示，我們現在知道音樂會影響心血管系統，如果我們瞭解如何發生作用，就可以利用它。
　　
　　這項研究線上發表於6月22日，以及6月30日的循環期刊。
　　
　　【操作音樂】
　　研究者追蹤24名年紀在24至26歲健康成人的心血管與呼吸資料，其中12人是有經驗的合唱者，12人是年紀與性別相仿、無音樂訓練的對照組。
　　
　　連結上心電圖(ECG)、眼睛閉上，研究對象以耳機聆聽各種音樂片段。這些音樂片段包括：貝多芬第9號交響曲的慢板，一段聞名的管弦樂；普契尼杜蘭朵公主中的公主徹夜未眠(Nessun dorma)，充滿感情和熱情的歌劇詠嘆調；巴哈清唱劇中的一段獨唱，一段充滿理智的曲目；韋瓦第那布果(Nabucco)中的詠嘆調，有節奏性的短篇；韋瓦第茶花女(La Traviata)中的詠嘆調，也是充滿節奏的段落。研究對象也會有2分鐘的寂靜片段。
　　
　　Bernardi醫師表示，研究者選擇這些段落是因為在音樂力學上包括各種改變，例如，漸強、漸弱、弱拍與強拍等等。他表示，如果你要看在心血管和呼吸系統是否有相同的變化，這些是理想的音樂類型。當然，歌劇是我們義大利的傳統之一。
　　
　　當研究對象聆聽音樂時，研究者監測他們的ECG、血壓、大腦血流、呼吸與皮膚血管收縮。他們蒐集個別的資料，且分別就各組和整體進行平均。
　　
　　為了測量有意識的感情波動，要求研究對象依照5分級距，將情感強度、音樂片段的愉悅與新奇度進行排序。他們也報告是否感到掃興或其他感覺。
　　
　　【無人感到掃興】
　　研究者發現，音樂中很少、或沒有情緒牽涉其中，沒有人對這些音樂感到掃興。
　　
　　但是研究者也發現，下意識的反應出自主反應。幾乎每段漸強音樂都會誘發越趨明顯的皮膚血管收縮以及增加血壓和心律。
　　
　　心血管變化與音樂之間的關聯在「公主徹夜未眠」這段詠嘆調中特別明顯，該段有3節逐漸增強的漸強段落。Bernardi醫師表示，我們發現有許多一致之處，特別是這些漸強片段。
　　
　　相反地，在緩慢或寂靜片段時，有漸進式的皮膚血管擴張和心律及血壓減少，表示逐漸放鬆。
　　
　　【類似的反應】
　　雖然音樂家充滿理智的曲目傾向比對照組更有反應，大致上來說，音樂家和非音樂家的心律資料是一樣的。Bernardi醫師表示，每個人的反應傾向相同，表示不論你喜歡音樂與否，這些特殊片段對每個人的效果一樣。
　　
　　至於呼吸，音樂和呼吸之間也傾向有關聯。作者表示，對於某些片段，呼吸訊號接近音效的幅度，表示呼吸深度受到音樂緊密影響，至少在漸強如此。音樂家對於一些音樂片段的反應關聯比非音樂家高些。
　　
　　Bernardi醫師總結表示，使用其他文化如中國或阿拉伯音樂進行的研究可能會有類似的結果。他表示，我認為使用不同音樂所表達出的每樣東西幾乎都是一樣，因為它的生理反應與情緒無關，也就是來自身體的反應而非情緒的反應。
　　
　　【更好的解釋】
　　音樂已經在多種領域中被用於治療，但是迄今還不知道它如何發生作用。Bernardi醫師表示，我們認為我們可以提供它如何作用的解釋，因此可以更佳的運用它。
　　
　　其他研究顯示，音樂可降低壓力、加強運動表現、促進神經缺損者的動作技能。音樂也可幫助分心而提供生理上的助益，讓病患可以運動更久一些。
　　
　　Bernardi等人之前的研究發現，較快速的節奏會增加呼吸、心律與血壓，當音樂停止時即會減慢。
　　
　　研究團隊的下一步驟是以更年長的族群、70歲以上者重複此一試驗，選擇的音樂片段將包括搖滾樂。
　　
　　【令人興奮的發現】
　　密西根醫院心臟復健與運動實驗室主任Barry Franklin醫師表示，就他看來，這是個令人興奮的研究。
　　
　　他表示，他希望看到在冠狀動脈患者也有類似的研究，以每日為基礎來看是否有同樣的生理反應。如果有，將會有很大的影響。Franklin醫師表示，對於嚴重功能不佳的病患，血壓、血流、心律的小小改善都會有有意義的適應與改善。
　　
　　芬蘭赫爾辛基Signe and Ane Gyllenberg基金會資助本研究。研究者報告無利益衝突。
　　
　　Circulation. 2009;線上發表於2009年6月22日。

Cardiac Rhythms Synchronize With Music

By Pauline Anderson
Medscape Medical News

June 30, 2009 — Music, particularly pieces that contain crescendos or gradual increases in volume, elicits synchronized cardiovascular and respiratory responses in young people that are similar in both musicians and nonmusicians, according to new research.

It is well-known that music can elicit strong positive or negative emotions, but this new research shows that music is also linked to unconscious physiological responses, said the study's lead author, Luciano Bernardi, MD, professor of internal medicine at Pavia University, in Italy.

"Here we show, probably for the first time, that there is a continuous interaction between the music dynamics and our cardiovascular system, whether there are conscious emotions or not," Dr. Bernardi said in an interview.

These findings could have implications for the potential use of music as a therapeutic tool, he added. "We know now that music can affect the cardiovascular system, and if we understand how this works, then we can use it," he said.

The research was published online June 22 and in the June 30 issue of Circulation.

Operative Music

Researchers tracked the cardiovascular and respiratory profile of 24 healthy subjects aged 24 to 26 years old, of whom 12 were experienced choristers and 12 were age- and sex-matched controls with no musical training.

Hooked up to an electrocardiogram (ECG) and with their eyes closed, the subjects listened to various pieces of music with headphones. The pieces included: An adagio from Beethoven's Ninth Symphony, a well-known orchestral piece; "Nessun dorma," an emotional and lyrical operatic aria from Puccini's Turandot; a solo vocal piece from 1 of Bach's cantatas, a more "intellectual" selection; an aria from Verdi's Nabucco, which has rhythmic phrases; and another aria from Verdi's La Traviata, also a rhythmic piece. The subjects were also exposed to 2 minutes of silence.

Researchers selected these pieces because they contain several changes in music dynamics — for example, crescendos, decrescendos, pianos, and fortes, etc, said Dr. Bernardi. "This is the ideal type of music to use if you want to see whether the same variation is mirrored in the cardiovascular and respiratory systems," he said. "And of course, operatic music is part of our music tradition in Italy."

While subjects listened to the music, researchers monitored their ECG, blood pressure, cerebral blood flow, respiration, and skin vasoconstriction. They collected individual data as well as averages for each of the 2 groups separately as well as all 24 subjects together.

To measure conscious emotional arousal, subjects were asked to rate the intensity of emotion and the novelty and pleasantness of the musical pieces on a 5-point scale. They also reported on whether they felt "chills" or other strong feelings in response to each track.

No "Chills"

The researchers found that there was little or no emotional involvement in the music, and none of the subjects reported chills in response to the music.

But the investigators did find subconscious reflex autonomous responses. Almost every musical crescendo induced progressive skin vasoconstriction along with increases in blood pressure and heart rate.

Correlations between cardiovascular variables and music profile were particularly evident during the aria "Nessun dorma," which is characterized by 3 progressively stronger crescendos. "We found that there were a lot of correspondences, particularly during the part of the musical track that has those crescendos," said Dr. Bernardi.

Conversely, during the slower or silent phases, there was progressive skin vasodilation and reductions in heart rate and blood pressure, indicating progressive relaxation.

Similar Responses

Although musicians tended to have a greater response than control subjects to more "intellectual" music, for the most part, the cardiac profile of musicians was the same as that of nonmusicians. "Everyone tended to respond in the same way, which suggests that whether you like it [the music] or not, these particular tracks have an effect that is common to everybody," said Dr. Bernardi.

As for respiration, there tended to be a correlation between music and breathing. For certain pieces, the respiratory signal closely tracked the amplitude of the music "envelope," indicating that the depth of respiration could be influenced tightly by music, at least during crescendos, said the authors. Musicians had a somewhat higher correlation for some musical pieces than nonmusicians.

Dr. Bernardi surmised that a study using music from other cultures – for example, Chinese or Arabic — would produce similar findings. "I would suggest that pretty much everything would be the same using people with a different musical system because it [physiological reaction] is dependent not on emotions" but rather on the body's reactions that are independent from emotional responses, he said.

Better Explanation

Music is already being used as a therapy in various fields, but until now little was known about how it works. "We think we can now provide an explanation of how it could work and therefore provide a better way of using it," said Dr. Bernardi.

Other research has shown that music reduces stress, boosts athletic performance, and enhances motor skills in people with neurological impairments. Music can also provide physical benefits by acting as a distraction so patients may be able to exercise for longer periods of time.

An earlier study by Dr. Bernardi and his colleagues found that faster tempos resulted in increased breathing, heart rate, and blood pressure, all of which decreased when the music was stopped.

The next step for his research group is to repeat the current study using an older patient population — those over age 70 years. The selection of musical pieces for this new study will include rock music, said Dr. Bernardi.

Provocative Findings

For his part, Barry Franklin, MD, director of cardiac rehabilitation and exercise laboratories at William Beaumont Hospital, in Royal Oak, Michigan, called the study "provocative."

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He said he would like to see similar studies done on coronary patients like the ones he deals with on a daily basis to see whether the physiologic responses are the same. If they are, there may be some huge implications, he said. In patients with tremendous functional deficits, even very small changes in blood pressure, blood flow, heart rate, and so on may produce meaningful adaptations and improvements in those individuals, Dr. Franklin noted.

The research was supported by a grant from the Signe and Ane Gyllenberg Foundation, in Helsinki, Finland. The researchers report no conflict of interest.

Circulation. 2009; Published online June 22, 2009.