Jäncke L, Wüstenberg T, Scheich H, Heinze H-J
Institute of Experimental and General Psychology, Otto-von-Guericke University Magdeburg, D-39106 Magdeburg, Germany.
Neuroimage. 2002 Apr;15(4):733-46. doi: 10.1006/nimg.2001.1027.
Recent functional neuroimaging studies have emphasized the role of the different areas within the left superior temporal sulcus (STS) for the perception of various speech stimuli. We report here the results of three independent studies additionally demonstrating hemodynamic responses in the vicinity of the planum temporale (PT). In these studies we used consonant-vowel (CV) syllables, tones, white noise, and vowels as acoustic stimuli in the context of whole-head functional magnetic resonance imaging, applying a long TR to attenuate possible masking effects by the scanner noise. To summarize, we obtained the following results for the contrasts comparing hemodynamic responses obtained during the perception of CV syllables compared to tones or white noise: (i) stronger activation in the vicinity of the left PT with two distinct foci of activation, one in a lateral position and the other more medial in the vicinity of Heschl's sulcus; (ii) stronger activation in the vicinity of the right PT; and (iii) stronger bilateral activation within the mid-STS. Further contrasts revealed the following findings: (iv) stronger bilateral activation to CV syllables than to vowels in the medial PT, (v) stronger left-sided activation to CV syllables than to vowels in the mid-STS, and (vi) stronger activation to CV syllables with voiceless initial consonants than to CV syllables with voiced initial consonants in the left medial PT. The results are compatible with the hypothesis that the STS contains neurons specialized for speech perception. However, these results also emphasize the role of the PT in the analysis of phonetic features, namely the voice-onset-time. Yet this does not mean that the PT is solely specialized for phonetic analysis. We hypothesize rather that the PT contains neurons specialized for the analysis of rapidly changing cues as was suggested by P. Tallal et al. (1993, Ann. N. Y. Acad. Sci. 682: 27-47).
近期的功能神经影像学研究强调了左颞上沟（STS）内不同区域在各种言语刺激感知中的作用。我们在此报告三项独立研究的结果，这些研究进一步证明了颞平面（PT）附近的血流动力学反应。在这些研究中，我们在全脑功能磁共振成像的背景下，使用辅音 - 元音（CV）音节、音调、白噪声和元音作为听觉刺激，并采用长重复时间（TR）来减弱扫描仪噪声可能产生的掩蔽效应。总之，在比较CV音节感知过程中获得的血流动力学反应与音调或白噪声时，我们得到了以下对比结果：（i）左PT附近有更强的激活，有两个不同的激活焦点，一个在外侧位置，另一个在赫氏沟附近更靠内侧；（ii）右PT附近有更强的激活；（iii）STS中部有更强的双侧激活。进一步的对比揭示了以下发现：（iv）在内侧PT中，对CV音节的双侧激活比对元音更强；（v）在STS中部，对CV音节的左侧激活比对元音更强；（vi）在左内侧PT中，对以清辅音开头的CV音节的激活比对以浊辅音开头的CV音节更强。这些结果与STS包含专门用于言语感知的神经元这一假设相符。然而，这些结果也强调了PT在语音特征分析中的作用，即语音起始时间。但这并不意味着PT仅专门用于语音分析。相反，我们假设PT包含专门用于分析快速变化线索的神经元，正如P. 塔拉尔等人（1993年，《纽约科学院学报》682：27 - 47）所建议的那样。
