Background: Motor speech treatment approaches have been applied in both adults with aphasia and apraxia of speech and children with speech-sound disorders. Identifying links between motor speech intervention techniques and the modes of action (MoA) targeted would improve our understanding of how and why motor speech interventions achieve their effects, along with identifying its effective components. The current study focuses on identifying potential MoAs for a specific motor speech intervention technique. Objectives: We aim to demonstrate that somatosensory inputs can influence lexical processing, thus providing further evidence that linguistic information stored in the brain and accessed as part of speech perception processes encodes information related to speech production. Methods: In a cross-modal repetition priming paradigm, we examined whether the processing of external somatosensory priming cues was modulated by both word-level (lexical frequency, low-or high-frequency) and speech sound articulatory features. The study participants were divided into two groups. The first group consisted of twenty-three native English speakers who received somatosensory priming stimulation to their oro-facial structures (either to labial corners or under the jaw). The second group consisted of ten native English speakers who participated in a control study where somatosensory priming stimulation was applied to their right or left forehead as a control condition. Results:The results showed significant somatosensory priming effects for the low-frequency words, where the congruent somatosensory condition yielded significantly shorter reaction times and numerically higher phoneme accuracy scores when compared to the incongruent somatosensory condition. Data from the control study did not reveal any systematic priming effects from forehead stimulation (nonspeech related site), other than a general (and expected) tendency for longer reaction times with low-frequency words. Conclusions: These findings provide further support for the notion that speech production information is represented in the mental lexicon and can be accessed through exogenous Speech-Language Pathologist driven somatosensory inputs related to place of articulation.

Null hypothesis significance testing (NHST) dominates quantitative data analysis, but its use is controversial and has been heavily criticized. The American Psychological Association has advocated the reporting of effect sizes (ES), confidence intervals (CIs), and statistical power analysis to complement NHST results to provide a more comprehensive understanding of research findings. The aim of this paper is to carry out a sample survey of statistical reporting practices in two journals with the highest h5-index scores in the areas of developmental disability and rehabilitation. Using a checklist that includes critical recommendations by American Psychological Association, we examined 100 randomly selected articles out of 456 articles reporting inferential statistics in the year 2013 in the Journal of Autism and Developmental Disorders (JADD) and Research in Developmental Disabilities (RDD). The results showed that for both journals, ES were reported only half the time (JADD 59.3%; RDD 55.87%). These findings are similar to psychology journals, but are in stark contrast to ES reporting in educational journals (73%). Furthermore, a priori power and sample size determination (JADD 10%; RDD 6%), along with reporting and interpreting precision measures (CI: JADD 13.33%; RDD 16.67%), were the least reported metrics in these journals, but not dissimilar to journals in other disciplines. To advance the science in developmental disability and rehabilitation and to bridge the research-to-practice divide, reforms in statistical reporting, such as providing supplemental measures to NHST, are clearly needed.

Tactile-kinesthetic-proprioceptive (TKP) input used to facilitate speech motor control is considered an active ingredient within speech motor interventions. Objective metrics identifying skill level differences across speech-language pathologists (S-LP) providing TKP cues are crucial for monitoring treatment delivery fidelity. The study examined three kinematic measures indicating accuracy and consistency of TKP inputs by 3 S-LPs with varying experience levels (S-LP 1: novice; S-LP 2 and S-LP 3: advanced). Confidence interval measures were used to compare the accuracy of jaw movement amplitudes of the vowel /a/ made by a model participant versus S-LPs giving the TKP input. Generalised Orthogonal Procrustes Analysis (GPA) and cyclic Spatial Temporal Index (cSTI) were used to determine movement consistency. Results revealed passive jaw excursions induced by S-LP 2 and 3 to be not statistically significant from the model participant's active jaw movements. cSTI values decreased with advanced level of experience (19.28, 12.14, and 9.33 for S-LP 1, S-LP 2, and S-LP 3, respectively). GPA analyses revealed a similar pattern for S-LPs with more experience demonstrating lower mean RMS values (0.22, 0.03, and 0.11 for S-LP 1, S-LP 2, and S-LP 3, respectively). Findings suggest kinematic measures adapted from the motor control literature can be applied to assess S-LP skill differences in providing TKP cues.