The effects of continuous oromotor activity on speech motor learning: speech biomechanics and neurophysiologic correlates

Abstract

Sustained limb motor activity has been used as a therapeutic tool for improving rehabilitation outcomes and is thought to be mediated by neuroplastic changes associated with activity-induced cortical excitability. Although prior research has reported enhancing effects of continuous chewing and swallowing activity on learning, the potential beneficial effects of sustained oromotor activity on speech improvements is not well-documented. This exploratory study was designed to examine the effects of continuous oromotor activity on subsequent speech learning. Twenty neurologically healthy young adults engaged in periods of continuous chewing and speech after which they completed a novel speech motor learning task. The motor learning task was designed to elicit improvements in accuracy and efficiency of speech performance across repetitions of eight-syllable nonwords. In addition, transcranial magnetic stimulation was used to measure the cortical silent period (cSP) of the lip motor cortex before and after the periods of continuous oromotor behaviors. All repetitions of the nonword task were recorded acoustically and kinematically using a three-dimensional motion capture system. Productions were analyzed for accuracy and duration, as well as lip movement distance and speed. A control condition estimated baseline improvement rates in speech performance. Results revealed improved speech performance following 10 min of chewing. In contrast, speech performance following 10 min of continuous speech was degraded. There was no change in the cSP as a result of either oromotor activity. The clinical implications of these findings are discussed in the context of speech rehabilitation and neuromodulation.

A novel tablet-based motor coordination test performs on par with the Beery VMI subtest and offers superior temporal metrics: findings from children with pediatric acute-onset neuropsychiatric syndrome

“…Linear mixed-effects models (LMMs) were used, as they present the advantage of accounting for a repeated and variable number of data points per participant (Snijders and Bosker 2012 ), thereby estimating the composite nested effect of all data points. The participants were included as random effects for the intercepts [c.f., Wit and Buxbaum ( 2017 ); Geers et al ( 2022 ); Runnalls et al ( 2019 ); Stipancic et al ( 2021 )] and the two directional metrics were set as predictors for the VMI MC score. The significance of the fixed effects in the nested model was assessed with F-tests, using the Satterthwaite method for degrees of freedom approximation, as implemented in the r package lme4 (Bates et al 2015 ).…”

Oromotor Nonverbal Performance and Speech Motor Control: Theory and Review of Empirical Evidence

“…[10,11] see critique of this logic in [12], pp. [135][136]. In Weismer [6], this is called the "common effectors" fallacy.…”

“…The results of [135] (Table 1) were judged to be mixed. There was a positive effect of chewing gum for ten minutes on a subsequent, challenging speech motor learning task.…”