Neural entrainment to speech modulates speech intelligibility

Lars Riecke, Elia Formisano, Bettina Sorger, Deniz Başkent, Etienne Gaudrain

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Speech is crucial for communication in everyday life. Speech-brain entrainment, the alignment of neural activity to the slow temporal fluctuations (envelope) of acoustic speech input, is a ubiquitous element of current theories of speech processing. Associations between speech-brain entrainment and acoustic speech signal, listening task, and speech intelligibility have been observed repeatedly. However, a methodological bottleneck has prevented so far clarifying whether speech-brain entrainment contributes functionally to (i.e., causes) speech intelligibility or is merely an epiphenomenon of it. To address this long-standing issue, we experimentally manipulated speech-brain entrainment without concomitant acoustic and task-related variations, using a brain stimulation approach that enables modulating listeners' neural activity with transcranial currents carrying speech-envelope information. Results from two experiments involving a cocktail-party-like scenario and a listening situation devoid of aural speech-amplitude envelope input reveal consistent effects on listeners' speech-recognition performance, demonstrating a causal role of speech-brain entrainment in speech intelligibility. Our findings imply that speech-brain entrainment is critical for auditory speech comprehension and suggest that transcranial stimulation with speech-envelope-shaped currents can be utilized to modulate speech comprehension in impaired listening conditions.

Original languageEnglish
Pages (from-to)161-169.e5
Number of pages14
JournalCurrent Biology
Volume28
Issue number2
DOIs
Publication statusPublished - 22 Jan 2018

Keywords

  • Journal Article
  • FINE-STRUCTURE CUES
  • CORTICAL ENTRAINMENT
  • ELECTRICAL-STIMULATION
  • PHASE ENTRAINMENT
  • TEMPORAL ENVELOPE
  • NETWORK ACTIVITY
  • CURRENT STIMULATION
  • NEURONAL OSCILLATIONS
  • COMPETING-SPEECH
  • HUMAN AUDITORY-CORTEX

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