How can audiovisual pathways enhance the temporal resolution of time-compressed speech in blind subjects?
How can audiovisual pathways enhance the temporal resolution of time-compressed speech in blind subjects?
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DOI：
10.3389/fpsyg.2013.00530
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发表时间：
2013-08-16
影响因子：
3.8
通讯作者：
Ackermann, Hermann
中科院分区：
文献类型：
--
作者：
Hertrich, Ingo;Dietrich, Susanne;Ackermann, Hermann
对于盲人来说，视觉通道无法通过唇读或视觉韵律来协助面对面的交流。然而，视觉系统可能会增强对听觉信息的评估，因为它与（1）听觉系统、（2）超模态表征和（3）额叶动作相关区域有交叉链接。除了空间或语音表示处理的反馈或自上而下的支持之外，实验数据表明视觉系统可以在更基本的计算阶段（例如时间信号分辨率）影响听觉感知。例如，与视力正常的受试者相比，盲人对后向掩蔽的抵抗力更强，并且这种能力似乎与视觉皮层的活动有关。关于连续语音的理解，盲人受试者可以学习使用加速文本到语音系统以超快的语速（>16个音节/秒）“阅读”文本，远远超过6个音节/秒的正常范围。一项功能性磁共振成像研究表明，在其他大脑区域中，这种能力与双侧枕丘、右侧视觉皮层和左侧辅助运动区的 BOLD 反应显着共变。此外，脑磁图测量揭示了右枕叶皮层中的一个特定成分与加速语音的音节起始锁相。对于视力正常的人来说，理解时间压缩语音的“瓶颈”似乎与缓冲语音材料的更高要求有关，并且可能与额叶大脑结构有关。另一方面，克服这一瓶颈的功能的神经生理学相关性似乎取决于早期视觉皮层活动。目前的假设和理论论文概述了一个模型，旨在将这些数据结合在一起，该模型基于早期的跨模态路径，这些路径已经从空间、时间和对象识别过程中跨模态调整的各种视听实验中得知。
In blind people, the visual channel cannot assist face-to-face communication via lipreading or visual prosody. Nevertheless, the visual system may enhance the evaluation of auditory information due to its cross-links to (1) the auditory system, (2) supramodal representations, and (3) frontal action-related areas. Apart from feedback or top-down support of, for example, the processing of spatial or phonological representations, experimental data have shown that the visual system can impact auditory perception at more basic computational stages such as temporal signal resolution. For example, blind as compared to sighted subjects are more resistant against backward masking, and this ability appears to be associated with activity in visual cortex. Regarding the comprehension of continuous speech, blind subjects can learn to use accelerated text-to-speech systems for "reading" texts at ultra-fast speaking rates (>16 syllables/s), exceeding by far the normal range of 6 syllables/s. A functional magnetic resonance imaging study has shown that this ability, among other brain regions, significantly covaries with BOLD responses in bilateral pulvinar, right visual cortex, and left supplementary motor area. Furthermore, magnetoencephalographic measurements revealed a particular component in right occipital cortex phase-locked to the syllable onsets of accelerated speech. In sighted people, the "bottleneck" for understanding time-compressed speech seems related to higher demands for buffering phonological material and is, presumably, linked to frontal brain structures. On the other hand, the neurophysiological correlates of functions overcoming this bottleneck, seem to depend upon early visual cortex activity. The present Hypothesis and Theory paper outlines a model that aims at binding these data together, based on early cross-modal pathways that are already known from various audiovisual experiments on cross-modal adjustments during space, time, and object recognition.