Abstract:
Direct neural recordings from human auditory cortex have demonstrated encoding for acoustic-phonetic features of consonants and vowels. Neural responses also encode distinct acoustic amplitude cues related to timing, such as those that occur at the onset of a sentence after a silent period or the onset of the vowel in each syllable. Here, we used a group reduced rank regression model to show that distributed cortical responses support a low-dimensional latent state representation of temporal context in speech. The timing cues each capture more unique variance than all other phonetic features and exhibit rotational or cyclical dynamics in latent space from activity that is widespread over the superior temporal gyrus. We propose that these spatially distributed timing signals could serve to provide temporal context for, and possibly bind across time, the concurrent processing of individual phonetic features, to compose higher-order phonological (e.g. word-level) representations.
摘要:
人类听觉皮层的直接神经记录已经证明了辅音和元音的声学语音特征的编码。神经反应还编码与定时相关的不同的声学振幅线索,例如在沉默期后的句子开始时或每个音节中的元音开始时发生的那些。这里,我们使用了一组降秩回归模型来表明分布式皮层反应支持语音中时间上下文的低维潜在状态表示。每个时间线索都比所有其他语音特征捕获更多的独特变化,并在潜在空间中表现出旋转或周期性动力学,这些活动广泛存在于颞上回。我们建议这些空间分布的定时信号可以用于提供时间上下文,可能会跨越时间,各个语音特征的并发处理,组成高阶语音(例如单词级别)表示。