Decoding kinematic information from beta-band motor rhythms of speech motor cortex: a methodological/analytic approach using concurrent speech movement tracking and magnetoencephalography.

Introduction: Articulography and functional neuroimaging are two major tools for studying the neurobiology of speech production. Until now, however, it has generally not been feasible to use both in the same experimental setup because of technical incompatibilities between the two methodologies. Methods: Here we describe results from a novel articulography system dubbed Magneto-articulography for the Assessment of Speech Kinematics (MASK), which is technically compatible with magnetoencephalography (MEG) brain scanning systems. In the present paper we describe our methodological and analytic approach for extracting brain motor activities related to key kinematic and coordination event parameters derived from time-registered MASK tracking measurements. Data were collected from 10 healthy adults with tracking coils on the tongue, lips, and jaw. Analyses targeted the gestural landmarks of reiterated utterances/ipa/ and /api/, produced at normal and faster rates. Results: The results show that (1) Speech sensorimotor cortex can be reliably located in peri-rolandic regions of the left hemisphere; (2) mu (8-12 Hz) and beta band (13-30 Hz) neuromotor oscillations are present in the speech signals and contain information structures that are independent of those present in higher-frequency bands; and (3) hypotheses concerning the information content of speech motor rhythms can be systematically evaluated with multivariate pattern analytic techniques. Discussion: These results show that MASK provides the capability, for deriving subject-specific articulatory parameters, based on well-established and robust motor control parameters, in the same experimental setup as the MEG brain recordings and in temporal and spatial co-register with the brain data. The analytic approach described here provides new capabilities for testing hypotheses concerning the types of kinematic information that are encoded and processed within specific components of the speech neuromotor system.

Road traffic noise and cognitive function in older adults: a cross-sectional investigation of The Irish Longitudinal Study on Ageing.

BACKGROUND: The World Health Organization published updated Environmental Noise Guidelines in 2018. Included are recommended limit values for environmental noise exposure based on systematic reviews for a range of health outcomes, including cognitive impairment. There is emerging evidence in the literature that chronic exposure to road traffic noise may affect cognitive function in older adults, but this relationship is not well established. This study spatially linked nationally representative health microdata from The Irish Longitudinal Study on Ageing to building-level modelled noise data for two cities in the Republic of Ireland. This was used to investigate associations between exposure to road traffic noise and cognitive function in a sample of older adults, independent of a range of socio-demographic and behavioural characteristics, as well as exposure to air pollution. METHODS: We used the Predictor-LimA Advanced V2019.02 software package to estimate noise originating from road traffic for the cities of Dublin and Cork in Ireland according to the new common noise assessment methodology for the European Union (CNOSSOS-EU). Noise exposure values were calculated for each building and spatially linked with geo-coded TILDA microdata for 1706 individuals aged 54 and over in the two cities. Ordinary least squares linear regression models were estimated for eight standardised cognitive tests including noise exposure as an independent variable, with standard errors clustered at the household level. Models were adjusted for individual sociodemographic, behavioural and environmental characteristics. RESULTS: We find some evidence that road traffic noise exposure is negatively associated with executive function, as measured by the Animal Naming Test, among our sample of older adults. This association appears to be accounted for by exposure to air pollution when focusing on a sub-sample. We do not find evidence of an association between noise exposure and memory or processing speed. CONCLUSIONS: Long term exposure to road traffic noise may be negatively associated with executive function among older adults.

Assessing the Treatment of Potential Effect Modifiers Informing World Health Organisation Guidelines for Environmental Noise.

Methodologies employed in the production of systematic reviews used to inform policy must be robust. In formulating the recent World Health Organisation (WHO) Environmental Noise Guidelines for the European Region, seven systematic reviews of evidence were commissioned to assess the relationship between environmental noise exposure and a range of health outcomes, six of which were nonauditory. Within the methodological guidance document devised for these reviews, inclusion and exclusion criteria for individual studies and existing reviews were applied in accordance with the Population-Exposure-Comparator-Outcome-Study (PECOS) framework for the evaluation of evidence. Specific criteria were defined for "populations" and source-specific "exposure", but no criteria were defined for the treatment of potential "effect modifiers". Furthermore, no criteria were set for the treatment of combined exposures. Employing a custom-designed assessment matrix, we assess the treatment of potential effect modifiers in the formulation of the aforementioned systematic reviews, all published in a Special Issue of the International Journal of Environmental Research and Public Health (IJERPH), titled "WHO Noise and Health Evidence Reviews". We identify substantial methodological variation in their treatment and propose the differentiation of "moderators" and "mediators" from "confounders" as the basis for criteria development-including combined exposures-for future systematic reviews.

MEG studies of sensorimotor rhythms: a review.

The human sensorimotor cortex demonstrates a variety of oscillatory activity that is strongly modulated by movement and somatosensory input. Studies using scalp EEG and intracranial electrical recordings have provided much of our current knowledge regarding the frequency and temporal specificity of these sensorimotor rhythms and their relationship to various movement parameters, however with limitations in identifying the underlying neural sources, and the variety of motor behaviors that can be studied, respectively. Magnetoencephalography (MEG) recordings, combined with spatial filtering source reconstruction methods, provide an ideal non-invasive method for the localization of sensorimotor rhythms and for describing their precise time course during a variety of motor tasks. This review describes the application of MEG to the study of oscillatory activity in the human sensorimotor cortex, including advances in localization techniques and recent contributions of MEG to our understanding of the functional role of these oscillations in both adult and developmental populations.