Brain oscillations have been shown to track the slow amplitude fluctuations
in speech during comprehension. Moreover, there is evidence that these
stimulus-induced cortical rhythms may persist even after the driving
stimulus has ceased. However, how exactly this neural entrainment shapes
speech perception remains debated. This behavioral study investigated
whether and how the frequency and phase of an entrained rhythm would
influence the temporal sampling of subsequent speech.
In two behavioral
experiments, participants were presented with slow and fast isochronous
tone sequences, followed by Dutch target words ambiguous between as
/ɑs/ “ash” (with a short vowel) and aas /a:s/ “bait”
(with a long vowel). Target words were presented at various phases
of the entrained rhythm. Both experiments revealed effects of the frequency
of the tone sequence on target word perception: fast sequences biased
listeners to more long /a:s/ responses. However, no evidence for phase
effects could be discerned.
These findings show
that an entrained rhythm’s frequency, but not phase, influences
the temporal sampling of subsequent speech. These outcomes are compatible
with theories suggesting that sensory timing is evaluated relative
to entrained frequency. Furthermore, they suggest that phase tracking
of (syllabic) rhythms by theta oscillations plays a limited role in
speech parsing.
Cite as: Bosker, H.R., Kösem, A. (2017) An Entrained Rhythm’s Frequency, Not Phase, Influences Temporal Sampling of Speech. Proc. Interspeech 2017, 2416-2420, doi: 10.21437/Interspeech.2017-73
@inproceedings{bosker17b_interspeech,
author={Hans Rutger Bosker and Anne Kösem},
title={{An Entrained Rhythm’s Frequency, Not Phase, Influences Temporal Sampling of Speech}},
year=2017,
booktitle={Proc. Interspeech 2017},
pages={2416--2420},
doi={10.21437/Interspeech.2017-73}
}