經(jīng)典的神經(jīng)科學(xué)理論認(rèn)為，各種感官信息是分別在特定區(qū)域被處理后才進(jìn)行整合,。但是，德國馬普學(xué)會生物控制論研究所進(jìn)行的一項(xiàng)最新研究表明,，這些信號的整合可能更早,，只有這樣，表情和話語,、聲音和觸覺,、嗅覺和味覺才能相匹配。
由Christoph Kayser帶領(lǐng)的研究小組通過研究短尾猿大腦聽覺皮層11個(gè)處理不同頻率聲音的區(qū)域,，繪制了視覺刺激響應(yīng)圖譜,，這為深入了解靈長類動物如何整合感官信息提供了依據(jù)，并有望推翻傳統(tǒng)的理論,。在近期的《神經(jīng)科學(xué)雜志》（Journal of Neuroscience）上,，研究人員表示，他們發(fā)現(xiàn)短尾猿在觀看錄像的時(shí)候,，即便聲頻被關(guān)掉,，負(fù)責(zé)處理聽力的大腦區(qū)域的后部袋狀結(jié)構(gòu)也會變得活躍起來。Kayser認(rèn)為,，這種反應(yīng)是短尾猿集中注意力并有意識地處理刺激的一種表現(xiàn),，可能是用于確定聲源的內(nèi)在機(jī)制的一部分,。
這一結(jié)果也支持了此前的一些研究，即人類大腦聽覺皮層的后部參與了對文字語言的理解,，但以前科學(xué)家們一直無法通過功能核磁共振成像（fMRI）來確定這一關(guān)系,。
Kayser和他的同事目前正在試圖建立一個(gè)更好的人類大腦聽覺皮層映射機(jī)制。華盛頓喬治敦大學(xué)醫(yī)學(xué)中心生理學(xué)家和生物物理學(xué)家Josef Rauschecker表示,，已經(jīng)有多項(xiàng)研究表明人類大腦組織與低等靈長類動物類似,，尤其在視覺系統(tǒng)方面。
對人類聽覺皮層處理多種感官信息方式的深入研究有助于科學(xué)家認(rèn)識閱讀障礙（Dyslexia）等聽覺問題,，并進(jìn)一步采取措施治療,。
英文原文摘要：
Functional Imaging Reveals Visual Modulation of Specific Fields in Auditory Cortex
Christoph Kayser, Christopher I. Petkov, Mark Augath, and Nikos K. Logothetis
Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany
Correspondence should be addressed to Christoph Kayser, Max Planck Institute for Biological Cybernetics, Spemannstrasse 38, 72076 Tübingen, Germany. Email: [email protected]
Merging the information from different senses is essential for successful interaction with real-life situations. Indeed, sensory integration can reduce perceptual ambiguity, speed reactions, or change the qualitative sensory experience. It is widely held that integration occurs at later processing stages and mostly in higher association cortices; however, recent studies suggest that sensory convergence can occur in primary sensory cortex. A good model for early convergence proved to be the auditory cortex, which can be modulated by visual and tactile stimulation; however, given the large number and small size of auditory fields, neither human imaging nor microelectrode recordings have systematically identified which fields are susceptible to multisensory influences. To reconcile findings from human imaging with anatomical knowledge from nonhuman primates, we exploited high-resolution imaging (functional magnetic resonance imaging) of the macaque monkey to study the modulation of auditory processing by visual stimulation. Using a functional parcellation of auditory cortex, we localized modulations to individual fields. Our results demonstrate that both primary (core) and nonprimary (belt) auditory fields can be activated by the mere presentation of visual scenes. Audiovisual convergence was restricted to caudal fields [prominently the core field (primary auditory cortex) and belt fields (caudomedial field, caudolateral field, and mediomedial field)] and continued in the auditory parabelt and the superior temporal sulcus. The same fields exhibited enhancement of auditory activation by visual stimulation and showed stronger enhancement for less effective stimuli, two characteristics of sensory integration. Together, these findings reveal multisensory modulation of auditory processing prominently in caudal fields but also at the lowest stages of auditory cortical processing.
Key words: fMRI; macaque monkey; multisensory integration; cross-modal; perception; auditory cortex
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