Ethnokinesiology: towards a neuromechanical understanding of cultural differences in movement.

Each individual's movements are sculpted by constant interactions between sensorimotor and sociocultural factors. A theoretical framework grounded in motor control mechanisms articulating how sociocultural and biological signals converge to shape movement is currently missing. Here, we propose a framework for the emerging field of aiming to provide a conceptual space and vocabulary to help bring together researchers at this intersection.

Tonguedness in speech: Lateral bias in lingual bracing.

This study examines the lateral biases in tongue movements during speech production. It builds on previous research on asymmetry in various aspects of human biology and behavior, focusing on the tongue's asymmetric behavior during speech. The findings reveal that speakers have a pronounced preference toward one side of the tongue during lateral releases with a majority displaying the left-side bias.

Cortical control of posture in fine motor skills: evidence from inter-utterance rest position.

The vocal tract continuously employs tonic muscle activity in the maintenance of postural configurations. Gamma-band activity in the sensorimotor cortex underlies transient movements during speech production, yet little is known about the neural control of postural states in the vocal tract. Simultaneously, there is evidence that sensorimotor beta-band activations contribute to a system of inhibition and state maintenance that is integral to postural control in the body.

Postural adaptation to microgravity underlies fine motor impairment in astronauts' speech.

Understanding the role of anti-gravity behaviour in fine motor control is crucial to achieving a unified theory of motor control. We compare speech from astronauts before and immediately after microgravity exposure to evaluate the role of anti-gravity posture during fine motor skills. Here we show a generalized lowering of vowel space after space travel, which suggests a generalized postural shift of the articulators.

Reduction of vowel space in Alzheimer's disease.

Reduced vowel space area (VSA) is a known effect of neurodegenerative diseases such as Parkinson's disease (PD). Using large publicly available corpuses, two experiments were conducted comparing the vowel space of speakers with and without Alzheimer's disease (AD) during spontaneous and read speech. First, a comparison of vowel distance found reduced distance in AD for English spontaneous speech, but not Spanish read speech.

Robustness of lateral tongue bracing under bite block perturbation.

Lateral tongue bracing is a lingual posture in which the sides of the tongue are held against the palate and upper molars, and has been observed cross-linguistically. However, it is unknown whether lateral bracing makes adjustments to external perturbation like other body postures. The present study aims to test the robustness of lateral tongue bracing with three experiments.

Gait change in tongue movement.

During locomotion, humans switch gaits from walking to running, and horses from walking to trotting to cantering to galloping, as they increase their movement rate. It is unknown whether gait change leading to a wider movement rate range is limited to locomotive-type behaviours, or instead is a general property of any rate-varying motor system. The tongue during speech provides a motor system that can address this gap.

F0-related head movement in blind versus sighted speakers.

This study investigated the relationship between head movement and fundamental frequency (F0) during speech by comparing continuous speech of congenitally blind and sighted speakers from YouTube videos. Positive correlations were found between F0 (measured in semitones) and vertical head movement for both speaker groups, with a stronger correlation for blind speakers. In addition, larger head movements and larger head movement per semitone ratios were observed for sighted speakers.

Quantal biomechanical effects in speech postures of the lips.

The unique biomechanical and functional constraints on human speech make it a promising area for research investigating modular control of movement. The present article illustrates how a modular control approach to speech can provide insights relevant to understanding both motor control and observed variation across languages. We specifically explore the robust typological finding that languages produce different degrees of labial constriction using distinct muscle groupings and concomitantly distinct lip postures.

Intravelar and Extravelar Portions of Soft Palate Muscles in Velic Constrictions: A Three-Dimensional Modeling Study.

Purpose This study predicts and simulates the function and relative contributions of the intravelar and extravelar portions of the levator veli palatini (LVP) and palatoglossus (PG) muscles in velic constrictions. Method A finite element-based model of the 3-dimensional upper airway structures (palate, pharynx, tongue, jaw, maxilla) was implemented, with LVP and PG divided into intravelar and extravelar portions. Simulations were run to investigate the contributions of these muscles in velopharyngeal port (VPP) closure and constriction of the oropharyngeal isthmus (OPI).

Visual-Tactile Speech Perception and the Autism Quotient.

Multisensory information is integrated asymmetrically in speech perception: An audio signal can follow video by 240ms, but can precede video by only 60ms, without disrupting the sense of synchronicity (Munhall et al., 1996). Similarly, air flow can follow either audio (Gick et al.

Cross-modal effects in speech perception.

Speech research during recent years has moved progressively away from its traditional focus on audition toward a more multisensory approach. In addition to audition and vision, many somatosenses including proprioception, pressure, vibration and aerotactile sensation are all highly relevant modalities for experiencing and/or conveying speech. In this article, we review both long-standing cross-modal effects stemming from decades of audiovisual speech research as well as new findings related to somatosensory effects.

Aerodigestive and communicative behaviors in anencephalic and hydranencephalic infants.

The aerodigestive and communicative behaviors of anencephalic and hydranencephalic patients are assessed from literature sources and are compared with documented neural structures present in the brainstem, subcortical, and cortical regions of the brain. Much of the data analyzed corroborate previous neurological studies, which focus on central pattern generators and development in model organisms. However, findings suggest that further research is necessary to determine which components of these systems support these behaviors.

Microtonal Variation in Sung Cantonese.

Background/aims: Both music and language impose constraints on fundamental frequency (F0) in sung music. Composers are known to set words of tone languages to music in a way that reflects tone height but fails to include tone contour. This study tests whether choral singers add linguistic tone contour information to an unfamiliar song by examining whether Cantonese singers make use of microtonal variation.

Prior Pronunciation Knowledge Bootstraps Word Learning.

Learners often struggle with L2 sounds, yet little is known about the role of prior pronunciation knowledge and explicit articulatory training in language acquisition. This study asks if existing pronunciation knowledge can bootstrap word learning, and whether short-term audiovisual articulatory training for tongue position with and without a production component has an effect on lexical retention. Participants were trained and tested on stimuli with perceptually salient segments that are challenging to produce.

Do innate stereotypies serve as a basis for swallowing and learned speech movements?

Keven & Akins suggest that innate stereotypies like TP/R may participate in the acquisition of tongue control. This commentary examines this claim in the context of speech motor learning and biomechanics, proposing that stereotypies could provide a basis for both swallowing and speech movements, and provides biomechanical simulation results to supplement neurological evidence for similarities between the two behaviors.

Computer-Assisted Visual Articulation Feedback in L2 Pronunciation Instruction: A Review.

Language learning is a multimodal endeavor; to improve their pronunciation in a new language, learners access not only auditory information about speech sounds and patterns, but also visual information about articulatory movements and processes. With the development of new technologies in computer-assisted pronunciation training (CAPT) come new possibilities for delivering feedback in both auditory and visual modalities. The present paper surveys the literature on computer-assisted visual articulation feedback, including direct feedback that provides visual models of articulation and indirect feedback that uses visualized acoustic information as a means to inform articulation instruction.

The Quantal Larynx: The Stable Regions of Laryngeal Biomechanics and Implications for Speech Production.

Purpose: Recent proposals suggest that (a) the high dimensionality of speech motor control may be reduced via modular neuromuscular organization that takes advantage of intrinsic biomechanical regions of stability and (b) computational modeling provides a means to study whether and how such modularization works. In this study, the focus is on the larynx, a structure that is fundamental to speech production because of its role in phonation and numerous articulatory functions.

Method: A 3-dimensional model of the larynx was created using the ArtiSynth platform (http://www.

Speaking Tongues Are Actively Braced.

Purpose: Bracing of the tongue against opposing vocal-tract surfaces such as the teeth or palate has long been discussed in the context of biomechanical, somatosensory, and aeroacoustic aspects of tongue movement. However, previous studies have tended to describe bracing only in terms of contact (rather than mechanical support), and only in limited phonetic contexts, supporting a widespread view of bracing as an occasional state, peculiar to specific sounds or sound combinations.

Method: The present study tests the pervasiveness and effortfulness of tongue bracing in continuous English speech passages using electropalatography and 3-D biomechanical simulations.

Visual-tactile integration in speech perception: Evidence for modality neutral speech primitives.

Audio-visual [McGurk and MacDonald (1976). Nature 264, 746-748] and audio-tactile [Gick and Derrick (2009). Nature 462(7272), 502-504] speech stimuli enhance speech perception over audio stimuli alone.

Effects of cosmetic tongue bifurcation on English fricative production.

Tongue bifurcation (also called 'splitting' or 'forking') is an increasingly popular cosmetic procedure in the body modification community that involves splitting the anterior tongue down the centre line. The implications of this procedure for speech have not been systematically studied; a few case studies have been published and suggest that there may be effects, primarily on fricatives. This article presents the first attempt to examine the acoustic implications of tongue bifurcation on speech production using a larger population sample.

EFFECTS OF MOUTHING AND INTERLOCUTOR PRESENCE ON MOVEMENTS OF VISIBLE VS. NON-VISIBLE ARTICULATORS.

Speakers take into account what information a conversation partner requires in a given context in order to best understand an utterance. Despite growing evidence showing that movements of visible articulators such as the lips are augmented in mouthed speech relative to vocalized speech, little to date has been done comparing this effect in visible vs. non-visible articulators.

Accommodation of end-state comfort reveals subphonemic planning in speech.

Applying the 'end-state comfort' hypothesis of Rosenbaum et al. [J Exp Psych Learn Mem Cogn 1992;18:1058; Acta Psychol (Amst) 1996;94:59] to tongue motion provides evidence of long-distance subphonemic planning in speech. Speakers' tongue postures may anticipate upcoming speech up to three segments, two syllables, and a morpheme or word boundary later.

Three speech sounds, one motor action: evidence for speech-motor disparity from English flap production.

The assumption that units of speech production bear a one-to-one relationship to speech motor actions pervades otherwise widely varying theories of speech motor behavior. This speech production and simulation study demonstrates that commonly occurring flap sequences may violate this assumption. In the word "Saturday," a sequence of three sounds may be produced using a single, cyclic motor action.