美國科學家近日研究發(fā)現(xiàn)，大腦處理聲音信號的區(qū)域同時也能處理視覺信號,，并且這兩種信號的同時處理時間要比之前認為的早得多,。這一發(fā)現(xiàn)有助于科學家深入理解大腦接收和匯總大量外部刺激的工作方式。相關論文近期在線發(fā)表于美國《國家科學院院刊》（PNAS）上,。
之前腦科學家一般認為,，人體的5種感覺（視覺、聽覺,、嗅覺,、觸覺和味覺）由各自單獨的、位于大腦中的通訊區(qū)域所支配,。這些區(qū)域分別處理這些信號,，并將處理后的信號傳輸給大腦皮層進行匯總,。
在最新的研究中，美國杜克大學的神經(jīng)生物學家Jennifer Groh和同事以猴子為實驗對象,，重點研究了下丘（inferior colliculus）,，它是信號從耳向大腦皮層傳輸?shù)淖畛鯉讉€停靠站之一,。研究人員發(fā)現(xiàn),，下丘上64%的神經(jīng)元不僅能運輸聽覺信號，也能運輸視覺信號,。這意味著,，聽覺信息和視覺信息很早就在一起進行了加工，之后才將組合信息傳到了大腦皮層,。
Groh說,，這應該就是口技能夠行得通的原因。觀眾還沒有有意識地考慮時,，口技表演者的聲音和木偶嘴巴的運動之間的聯(lián)系就已經(jīng)在他們腦中形成了,。
Groh還表示，人類大腦的下丘與猴子的相似,，隨著新技術的涌現(xiàn),，比如能夠?qū)崟r成像的功能核磁共振成像（fMRI）技術，我們將能夠在人類身上進行類似的研究,。Groh目前正和研究小組進行新的實驗,，以確定是否某種感覺影響了機體對另一種感覺的感知。（科學網(wǎng) 杰克·梅/編譯）
原始出處:
Published online before print October 31, 2007
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0706249104
OPEN ACCESS ARTICLE
Visual- and saccade-related signals in the primate inferior colliculus
Kristin Kelly Porter*, Ryan R. Metzger, and Jennifer M. Groh
Center for Cognitive Neuroscience, Department of Psychology and Neuroscience and Department of Neurobiology, Duke University, Durham, NC 27708
Edited by Eric I. Knudsen, Stanford University School of Medicine, Stanford, CA, and approved August 23, 2007 (received for review July 3, 2007)
Abstract
The inferior colliculus (IC) is normally thought of as a predominantly auditory structure because of its early position in the ascending auditory pathway just before the auditory thalamus. Here, we show that a majority of IC neurons (64% of 180 neurons) in awake monkeys carry visual- and/or saccade-related signals in addition to their auditory responses (P < 0.05). The response patterns involve primarily excitatory visual responses, but also increased activity time-locked to the saccade, slow rises in activity time-locked to the onset of the visual stimulus, and inhibitory responses. The presence of these visual-related signals suggests that the IC plays a role in integrating visual and auditory information. More broadly, our results show that interactions between sensory pathways can occur at very early points in sensory processing streams, which implies that multisensory integration may be a low-level rather than an exclusively high-level process.
auditory | monkey | multisensory | vision | cross-modal
