Belin P, Zilbovicius M, Crozier S, Thivard L, Fontaine A, Masure M C, Samson Y
Service Hospitalier Frédéric Joliot, Département de Recherche Médicale, Orsay, France.
J Cogn Neurosci. 1998 Jul;10(4):536-40. doi: 10.1162/089892998562834.
To investigate the role of temporal processing in language lateralization, we monitored asymmetry of cerebral activation in human volunteers using positron emission tomography (PET). Subjects were scanned during passive auditory stimulation with nonverbal sounds containing rapid (40 msec) or extended (200 msec) frequency transitions. Bilateral symmetric activation was observed in the auditory cortex for slow frequency transitions. In contrast, left-biased asymmetry was observed in response to rapid frequency transitions due to reduced response of the right auditory cortex. These results provide direct evidence that auditory processing of rapid acoustic transitions is lateralized in the human brain. Such functional asymmetry in temporal processing is likely to contribute to language lateralization from the lowest levels of cortical processing.
为了研究时间加工在语言侧化中的作用，我们使用正电子发射断层扫描（PET）监测了人类志愿者大脑激活的不对称性。在对包含快速（40毫秒）或延长（200毫秒）频率转换的非语言声音进行被动听觉刺激期间对受试者进行扫描。对于缓慢的频率转换，在听觉皮层中观察到双侧对称激活。相比之下，由于右侧听觉皮层反应减弱，在对快速频率转换的反应中观察到左侧偏向的不对称性。这些结果提供了直接证据，表明快速声学转换的听觉加工在人类大脑中是侧化的。时间加工中的这种功能不对称可能从皮层加工的最低水平就有助于语言侧化。
