Effects of task demands on neural correlates of acoustic and semantic processing in challenging listening conditions

Dhatri S. Devaraju, Amy Kemp, David A. Eddins, Rahul Shrivastav, Bharath Chandrasekaran*, Amanda Hampton Wray*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Purpose: Listeners shift their listening strategies between lower level acoustic information and higher level semantic information to prioritize maximum speech intelligibility in challenging listening conditions. Although increasing task demands via acoustic degradation modulates lexical-semantic processing, the neural mechanisms underlying different listening strategies are unclear. The current study examined the extent to which encoding of lower level acoustic cues is modulated by task demand and associations with lexical-semantic processes. Method: Electroencephalography was acquired while participants listened to sentences in the presence of four-talker babble that contained either higher or lower probability final words. Task difficulty was modulated by time available to process responses. Cortical tracking of speech—neural correlates of acoustic temporal envelope processing—were estimated using temporal response functions. Results: Task difficulty did not affect cortical tracking of temporal envelope of speech under challenging listening conditions. Neural indices of lexical-semantic processing (N400 amplitudes) were larger with increased task difficulty. No correlations were observed between the cortical tracking of temporal envelope of speech and lexical-semantic processes, even after controlling for the effect of individualized signal-to-noise ratios. Conclusions: Cortical tracking of the temporal envelope of speech and semantic processing are differentially influenced by task difficulty. While increased task demands modulated higher level semantic processing, cortical tracking of the temporal envelope of speech may be influenced by task difficulty primarily when the demand is manipulated in terms of acoustic properties of the stimulus, consistent with an emerging perspective in speech perception.

Original languageEnglish (US)
Pages (from-to)3697-3706
Number of pages10
JournalJournal of Speech, Language, and Hearing Research
Volume64
Issue number9
DOIs
StatePublished - Sep 2021

ASJC Scopus subject areas

  • Speech and Hearing
  • Language and Linguistics
  • Linguistics and Language

Fingerprint

Dive into the research topics of 'Effects of task demands on neural correlates of acoustic and semantic processing in challenging listening conditions'. Together they form a unique fingerprint.

Cite this