Discrimination of speech and non-speech sounds following theta-burst stimulation of the motor cortex

Rogers, Jack C. and Mottonen, Riikka and Boyles, Rowan and Watkins, Kate E. (2014) Discrimination of speech and non-speech sounds following theta-burst stimulation of the motor cortex. Frontiers in Psychology, 5. ISSN 1664-1078

[thumbnail of Rogers et al., 2014.pdf]
Preview
Text
Rogers et al., 2014.pdf - Published Version
Available under License Creative Commons Attribution.

Download (1MB)

Abstract

Perceiving speech engages parts of the motor system involved in speech production. The role of the motor cortex in speech perception has been demonstrated using low-frequency repetitive transcranial magnetic stimulation (rTMS) to suppress motor excitability in the lip representation and disrupt discrimination of lip-articulated speech sounds (Möttönen and Watkins, 2009). Another form of rTMS, continuous theta-burst stimulation (cTBS),
can produce longer-lasting disruptive effects following a brief train of stimulation. We investigated the effects of cTBS on motor excitability and discrimination of speech and nonspeech sounds. cTBS was applied for 40 s over either the hand or the lip representation of motor cortex. Motor-evoked potentials recorded from the lip and hand muscles in response to single pulses ofTMS revealed no measurable change in motor excitability due to cTBS.
This failure to replicate previous findings may reflect the unreliability of measurements of motor excitability related to inter-individual variability. We also measured the effects of cTBS on a listener’s ability to discriminate: (1) lip-articulated speech sounds from sounds not articulated by the lips (“ba” vs. “da”); (2) two speech sounds not articulated by the lips (“ga” vs. “da”); and (3) non-speech sounds produced by the hands (“claps” vs. “clicks”).
Discrimination of lip-articulated speech sounds was impaired between 20 and 35 min after cTBS over the lip motor representation. Specifically, discrimination of across-category ba–da sounds presented with an 800-ms inter-stimulus interval was reduced to chance level
performance. This effect was absent for speech sounds that do not require the lips for articulation and non-speech sounds. Stimulation over the hand motor representation did not affect discrimination of speech or non-speech sounds. These findings show that stimulation of the lip motor representation disrupts discrimination of speech sounds in an articulatory feature-specific way.

Item Type: Article
Identification Number: 10.3389/fpsyg.2014.00754
Dates:
Date
Event
27 June 2014
Accepted
15 July 2014
Published
Subjects: CAH04 - psychology > CAH04-01 - psychology > CAH04-01-01 - psychology (non-specific)
Divisions: Faculty of Business, Law and Social Sciences > College of Psychology
Depositing User: Silvio Aldrovandi
Date Deposited: 03 Apr 2018 16:34
Last Modified: 11 Jun 2024 13:03
URI: https://www.open-access.bcu.ac.uk/id/eprint/5798

Actions (login required)

View Item View Item

Research

In this section...