Impact of Motor Speech Intervention on Neural Activity in Children with Speech Sound Disorders: Use of Magnetoencephalography

Abstract

We present the novel use of a neuroimaging technique, magnetoencephalography (MEG), for examining therapy-related changes in neural activity during a speech and a non-speech motor task in children with speech sound disorders (SSD). Nine children (mean age = 4.2 years) with SSD were scanned in the MEG before and after an eight-week course of intensive motor speech therapy. MEG tasks involved an oromotor and a syllable production task. MEG analyses identified significant post-therapy changes in brain regions related to oromotor control and speech production. Behavioral assessments showed significant improvements on measures of motor speech skills and articulation following intervention. This is the first demonstration of the ability of MEG to: 1) capture brain activations resulting from oromotor movements and simple syllable production in young children, and 2) capture brain changes related to speech therapy. As the findings from this study are promising, we discuss directions for the design of future studies to further examine specific neural dysfunctions in speech sound disorders.

Cross-Modal Somatosensory Repetition Priming and Speech Processing

“…A magnetic resonance imaging study by Kadis et al [63] revealed that PROMPT intervention induced thinning of the left posterior superior temporal gyrus (Wernicke's area) in eight of nine children with CAS. Similarly, in Yu et al [64] study, participants demonstrated significant differences in cortical neural activity during speech tasks as a function of PROMPT intervention on magnetoencephalog-raphy recordings. In both these studies, significant improvements in speech motor control and speech articulation were also observed following the intervention.…”

“…The question remains whether specific exogenous S-LP driven somatosensory inputs in clinical rehabilitation settings constitute an "active ingredient" underlying MoAs in motor speech interventions such as the PROMPT approach. As described in Hayden et al [1] recent research studies from independent laboratories have demonstrated changes in cortical spatial-temporal neural activity and brain structure following PROMPT intervention [62][63][64]. A magnetic resonance imaging study by Kadis et al [63] revealed that PROMPT intervention induced thinning of the left posterior superior temporal gyrus (Wernicke's area) in eight of nine children with CAS.…”

“…The discovery of MoAs of motor speech intervention will hopefully permit the development of future research directed at modifying existing techniques to replicate such neural effects, adjust the dosage to elicit systematic effects in targeted neural pathways and potentially discover populations that are responsive to motor speech interventions [1]. Thus, converging evidence from behavioural data in children [14], adults [18][19][20][21], perceptual data from cross-modal research [9,10], and neuroimaging studies [62][63][64] seem to reinforce the notion that somatosensory inputs may be a potential active ingredient in motor speech interventions.…”

Enhancing Speech Rehabilitation in a Young Adult with Trisomy 21: Integrating Transcranial Direct Current Stimulation (tDCS) with Rapid Syllable Transition Training for Apraxia of Speech

“…In recent years, there has been a push towards studying the "mode of action" (MoA) through which interventions induce change (e.g., see [15]). Understanding the connection(s) between interventions and the MoA they target would broaden our scientific knowledge on how and why interventions affect change and may result in the development of more effective speech motor interventions (e.g., see [16][17][18]).…”

Transcranial Direct Current Stimulation (tDCS) Paired with ReST Training in Apraxia of Speech in Young Adult with Trisomy 21

“…Understanding the connection(s) between the interventions and the MoA they target would broaden our scientific knowledge on how and why interventions affect change and may result in the development of more effective speech motor interventions (e.g., see (Kadis et al, 2014;A.K. ;Namasivayam et al, 2022) and (Yu et al, 2018)).…”