Evaluating the use of cortical entrainment to measure atypical speech processing: A systematic review

Abstract

Background: Cortical entrainment has emerged as a promising means for measuring continuous speech processing in young, neurotypical adults. However, its utility for capturing atypical speech processing has not been systematically reviewed.

Objectives: Synthesize evidence regarding the merit of measuring cortical entrainment to capture atypical speech processing and recommend avenues for future research.

Method: We systematically reviewed publications investigating entrainment to continuous speech in populations with auditory processing differences.

Results: In the 25 publications reviewed, most studies were conducted on older and/or hearing-impaired adults, for whom slow-wave entrainment to speech was often heightened compared to controls. Research conducted on populations with neurodevelopmental disorders, in whom slow-wave entrainment was often reduced, was less common. Across publications, findings highlighted associations between cortical entrainment and speech processing performance differences.

Conclusions: Measures of cortical entrainment offer a useful means of capturing speech processing differences and future research should leverage them more extensively when studying populations with neurodevelopmental disorders.

Keywords: Acoustic envelope; Continuous speech; Cortical entrainment; Hearing impairment; Neural tracking; Neurodevelopmental disorders; Old age; Speech processing.