據(jù)統(tǒng)計(jì)有10%的人先天五音不全,，唱歌跑調(diào),。最新一項(xiàng)研究證明這可能由于大腦回路缺陷造成。
一種被稱為弓狀束的神經(jīng)纖維鏈接大腦中知覺(jué)和運(yùn)動(dòng)區(qū)域,，如果這條連接受損,，就會(huì)導(dǎo)致不能準(zhǔn)確控制音準(zhǔn)，這項(xiàng)研究發(fā)表在最新的神經(jīng)科學(xué)雜志上面,。
研究人員通過(guò)核磁共振彌散張量成像技術(shù)檢測(cè)大腦右顳和額葉間的聯(lián)系,，發(fā)現(xiàn)弓狀束參與鏈接發(fā)音感知和發(fā)音控制。經(jīng)過(guò)檢測(cè)的20人中有一半以上的人被查出不能準(zhǔn)確發(fā)聲,。在發(fā)聲不準(zhǔn)的人中,，弓狀束一般體積較小，纖維含量低,。以最先進(jìn)的方法在右半腦中都無(wú)法檢測(cè)出弓狀束分支存在,，研究人員推測(cè)可能是弓狀束分支完全缺失或者變形。
根據(jù)以往的研究和最新研究結(jié)果,，研究人員表示發(fā)聲不準(zhǔn)的人不能自主的聽見自己歌聲,，所以造成唱歌跑調(diào)。（生物谷Bioon.com）
生物谷推薦原始出處：
The Journal of Neuroscience, August 19, 2009, 29(33):10215-10220; doi:10.1523/JNEUROSCI.1701-09.2009
Tone Deafness: A New Disconnection Syndrome?
Psyche Loui,1 David Alsop,2 and Gottfried Schlaug1
Departments of 1Neurology and 2Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215
Communicating with one's environment requires efficient neural interaction between action and perception. Neural substrates of sound perception and production are connected by the arcuate fasciculus (AF). Although AF is known to be involved in language, its roles in non-linguistic functions are unexplored. Here, we show that tone-deaf people, with impaired sound perception and production, have reduced AF connectivity. Diffusion tensor tractography and psychophysics were assessed in tone-deaf individuals and matched controls. Abnormally reduced AF connectivity was observed in the tone deaf. Furthermore, we observed relationships between AF and auditory–motor behavior: superior and inferior AF branches predict psychophysically assessed pitch discrimination and sound production perception abilities, respectively. This neural abnormality suggests that tone deafness leads to a reduction in connectivity resulting in pitch-related impairments. Results support a dual-stream anatomy of sound production and perception implicated in vocal communications. By identifying white matter differences and their psychophysical correlates, results contribute to our understanding of how neural connectivity subserves behavior.
