Hsieh L, Gandour J, Wong D, Hutchins G D
Department of Audiology and Speech Sciences, Purdue University, West Lafayette, IN 47907-1353, USA.
Brain Lang. 2001 Mar;76(3):227-52. doi: 10.1006/brln.2000.2382.
A crosslinguistic, positron emission tomography (PET) study was conducted to determine the influence of linguistic experience on the perception of segmental (consonants and vowels) and suprasegmental (tones) information. Chinese and English subjects (10 per group) were presented binaurally with lists consisting of five Chinese monosyllabic morphemes (speech) or low-pass-filtered versions of the same stimuli (nonspeech). The first and last items were targeted for comparison; the time interval between target tones was filled with irrelevant distractor tones. A speeded-response, selective attention paradigm required subjects to make discrimination judgments of the target items while ignoring intervening distractor tones. PET scans were acquired for five tasks presented twice: one passive listening to pitch (nonspeech) and four active (speech = consonant, vowel, and tone; nonspeech = pitch). Significant regional changes in blood flow were identified from comparisons of group-averaged images of active tasks relative to passive listening. Chinese subjects show increased activity in left premotor cortex, pars opercularis, and pars triangularis across the four tasks. English subjects, on the other hand, show increased activity in left inferior frontal gyrus regions only in the vowel task and in right inferior frontal gyrus regions in the pitch task. Findings suggest that functional circuits engaged in speech perception depend on linguistic experience. All linguistic information signaled by prosodic cues engages left-hemisphere mechanisms. Storage and executive processes of working memory that are implicated in phonological processing are mediated in discrete regions of the left frontal lobe.
一项跨语言的正电子发射断层扫描（PET）研究旨在确定语言经验对语音（辅音和元音）和超音段（声调）信息感知的影响。以双耳方式向中国和英国受试者（每组10人）呈现由五个中文单音节语素组成的列表（语音）或相同刺激的低通滤波版本（非语音）。对第一个和最后一个项目进行比较；目标声调之间的时间间隔用无关的干扰声调填充。一种快速反应、选择性注意范式要求受试者在忽略中间干扰声调的同时对目标项目进行辨别判断。对五个任务进行了两次PET扫描：一次是被动听音高（非语音），四次是主动任务（语音=辅音、元音和声调；非语音=音高）。通过将主动任务的组平均图像与被动听音进行比较，确定了血流的显著区域变化。中国受试者在四项任务中左前运动皮层、岛盖部和三角部的活动增加。另一方面，英国受试者仅在元音任务中左额下回区域活动增加，在音高任务中右额下回区域活动增加。研究结果表明，参与语音感知的功能回路取决于语言经验。韵律线索所传达的所有语言信息都涉及左半球机制。与语音处理相关的工作记忆的存储和执行过程在左额叶的离散区域中进行调节。
