Speech comprehension is correlated with temporal response patterns recorded from auditory cortex

By E. Ahissar, Srikantan S. Nagarajan, Merav Ahissar, Athanassios Protopapas, H. Mahncke, Michael M. Merzenich. Proceedings of the National Academy of Sciences of the United States of America, 2001

542 citations recorded by the source corpus.

Speech comprehension depends on the integrity of both the spectral content and temporal envelope of the speech signal. Although neural processing underlying spectral analysis has been intensively studied, less is known about the processing of temporal information. Most of speech information conveyed by the temporal envelope is confined to frequencies below 16 Hz, frequencies that roughly match spontaneous and evoked modulation rates of primary auditory cortex neurons. To test the importance of cortical modulation rates for speech processing, we manipulated the frequency of the temporal envelope of speech sentences and tested the effect on both speech comprehension and cortical activity. Magnetoencephalographic signals from the auditory cortices of human subjects were recorded while they were performing a speech comprehension task. The test sentences used in this task were compressed in time. Speech comprehension was degraded when sentence stimuli were presented in more rapid (more compressed) forms. We found that the average comprehension level, at each compression, correlated with (i) the similarity between the frequencies of the temporal envelopes of the stimulus and the subject's cortical activity (“stimulus-cortex frequency-matching”) and (ii) the phase-locking (PL) between the two temporal envelopes (“stimulus-cortex PL”). Of these two correlates, PL was significantly more indicative for single-trial success. Our results suggest that the match between the speech rate and the a priori modulation capacities of the auditory cortex is a prerequisite for comprehension. However, this is not sufficient: stimulus-cortex PL should be achieved during actual sentence presentation.

Subfields: Cognitive Neuroscience

View Paper: https://www.semanticscholar.org/paper/d8776518e25977c4b38329f3b85c0a5394e84488

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Citations in the corpus

Unsupervised word discovery from speech using automatic segmentation into syllable-like units (2015, background): “Neural oscillations in auditory cortical areas are synchronized to the amplitude envelope of speech; this phaselocking may be required for speech comprehension [19].”
Distinct contributions of low- and high-frequency neural oscillations to speech comprehension (2017, background): “(Ahissar et al., 2001), the loss of spectral complexity using noise-vocoded speech (Peelle et al.”
The Encoding of Speech Sounds in the Superior Temporal Gyrus (2019, background): “Although the specific functional roles of this region are less clear, there is extensive evidence from non-invasive methods that neural activity in human auditory cortex is correlated with fluctuations in the amplitude envelope of the speech signal (Ahissar et al., 2001; Ding et al., 2014; Doelling ”
Linking Speech Perception and Neurophysiology: Speech Decoding Guided by Cascaded Oscillators Locked to the Input Rhythm (2011, background): “A third property emerges from a hypothesis, central to Tempo: (3) the oscillators are capable of remaining locked to the input rhythm as its changes (slowly) with time (Ahissar et al., 2001; Nourski et al., 2009), implying that the cycle durations of the oscillators adapt to the input.”
Neural processing of amplitude-modulated sounds. (2004, background): “These magnetic responses lock to the temporal envelope of speech signals, and the degree of locking correlates with speech comprehension (3).”
Phase patterns of neuronal responses reliably discriminate speech in human auditory cortex. (2007, background): “The correlation between the phase tracking and speech intelligibility also matches relevant previous research, in particular an MEG experiment revealing that cortical responses show decreased tracking performance for compressed speech (Ahissar et al., 2001).”
The Natural Statistics of Audiovisual Speech (2009, background): “auditory cortical activity cannot track its modulations and there is a corresponding loss of intelligibility [56].”
Across-Language Perspective on Speech Information Rate (2011, background): “…lines, frequency matching and phase locking between the speech rate and activations in the auditory cortex during a task of speech comprehension (Ahissar et al. 2001) would be worth investigating in a cross-language perspective to elucidate whether these synchronizations are also sensitive to…”
Acoustic landmarks drive delta-theta oscillations to enable speech comprehension by facilitating perceptual parsing (2013, background): “Such correspondence has been observed with other speech corpora, e.g., sentences in Ahissar et al. (2001).”
The human auditory cortex concurrently tracks syllabic and phonemic timescales via acoustic spectral flux (2024, unknown): “Hence, theta speech tracking is believed to be a necessary—but not sufficient—condition for speech comprehension to occur ( 31 – 35 ).”