Mummery C J, Ashburner J, Scott S K, Wise R J
Wellcome Department of Cognitive Neurology, Institute of Neurology, London, United Kingdom.
J Acoust Soc Am. 1999 Jul;106(1):449-57. doi: 10.1121/1.427068.
This positron emission tomography study used a correlational design to investigate neural activity during speech perception in six normal subjects and two aphasic patients. The normal subjects listened either to speech or to signal-correlated noise equivalents; the latter were nonspeech stimuli, similar to speech in complexity but not perceived as speechlike. Regions common to the auditory processing of both types of stimuli were dissociated from those specific to spoken words. Increasing rates of presentation of both speech and nonspeech correlated with cerebral activity in bilateral transverse gyri and adjacent superior temporal cortex. Correlations specific to speech stimuli were located more anteriorly in both superior temporal sulci. The only asymmetry in normal subjects was a left lateralized response to speech in the posterior superior temporal sulcus, corresponding closely to structural asymmetry on the subjects' magnetic resonance images. Two patients, who had left temporal infarction but performed well on single word comprehension tasks, were also scanned while listening to speech. These cases showed right superior temporal activity correlating with increasing rates of hearing speech, but no significant left temporal activation. These findings together suggest that the dorsolateral temporal cortex of both hemispheres can be involved in prelexical processing of speech.
这项正电子发射断层扫描研究采用相关设计，以调查6名正常受试者和2名失语症患者在言语感知过程中的神经活动。正常受试者分别聆听言语或与信号相关的噪声等效物；后者为非言语刺激，其复杂性与言语相似，但不被视为类似言语。两种刺激的听觉处理共有的区域与特定于口语单词的区域相分离。言语和非言语呈现速率的增加均与双侧颞横回和相邻的颞上皮质的大脑活动相关。特定于言语刺激的相关性在双侧颞上沟中更靠前。正常受试者唯一的不对称性是颞上沟后部对言语的左侧化反应，这与受试者磁共振图像上的结构不对称密切对应。两名患有左侧颞叶梗死但在单字理解任务中表现良好的患者在聆听言语时也进行了扫描。这些病例显示右侧颞上活动与听言语速率的增加相关，但左侧颞叶无明显激活。这些发现共同表明，两个半球的背外侧颞叶皮质都可能参与言语的词汇前处理。
