Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD, Maastricht, The Netherlands.
Maastricht Brain Imaging Centre, 6200 MD, Maastricht, The Netherlands.
Commun Biol. 2024 Sep 30;7(1):1217. doi: 10.1038/s42003-024-06913-z.
Invasive and non-invasive electrophysiological measurements during "cocktail-party"-like listening indicate that neural activity in the human auditory cortex (AC) "tracks" the envelope of relevant speech. However, due to limited coverage and/or spatial resolution, the distinct contribution of primary and non-primary areas remains unclear. Here, using 7-Tesla fMRI, we measured brain responses of participants attending to one speaker, in the presence and absence of another speaker. Through voxel-wise modeling, we observed envelope tracking in bilateral Heschl's gyrus (HG), right middle superior temporal sulcus (mSTS) and left temporo-parietal junction (TPJ), despite the signal's sluggish nature and slow temporal sampling. Neurovascular activity correlated positively (HG) or negatively (mSTS, TPJ) with the envelope. Further analyses comparing the similarity between spatial response patterns in the single speaker and concurrent speakers conditions and envelope decoding indicated that tracking in HG reflected both relevant and (to a lesser extent) non-relevant speech, while mSTS represented the relevant speech signal. Additionally, in mSTS, the similarity strength correlated with the comprehension of relevant speech. These results indicate that the fMRI signal tracks cortical responses and attention effects related to continuous speech and support the notion that primary and non-primary AC process ongoing speech in a push-pull of acoustic and linguistic information.
在类似于“鸡尾酒会”的聆听环境中进行的侵入性和非侵入性电生理测量表明,人类听觉皮层(AC)中的神经活动“跟踪”相关语音的包络。然而,由于覆盖范围和/或空间分辨率有限,主要和非主要区域的独特贡献仍不清楚。在这里,我们使用 7 特斯拉 fMRI 测量了参与者在存在和不存在另一个说话者的情况下专注于一个说话者时的大脑反应。通过体素建模,我们观察到双侧 Heschl gyrus(HG)、右侧中颞上回(mSTS)和左侧颞顶联合区(TPJ)的包络跟踪,尽管信号的迟缓性质和缓慢的时间采样。神经血管活动与包络呈正相关(HG)或负相关(mSTS、TPJ)。进一步分析比较了单说话者和同时说话者条件下空间响应模式之间的相似性和包络解码表明,HG 中的跟踪反映了相关和(在较小程度上)不相关的语音,而 mSTS 则代表了相关的语音信号。此外,在 mSTS 中,相似性强度与相关语音的理解相关。这些结果表明,fMRI 信号跟踪与连续语音相关的皮层反应和注意力效应,并支持这样的观点,即主要和非主要 AC 以声学分和语言信息的推拉方式处理持续的语音。