RESUMO
When given a series of sinusoidal oscillations in which the two hemicycles have equal amplitude but asymmetric velocity, healthy subjects lose perception of the slower hemicycle (SHC), reporting a drift towards the faster hemicycle (FHC). This response is not reflected in the vestibular-ocular reflex, suggesting that the adaptation is of higher order. This study aimed to define EEG correlates of this adaptive response. Twenty-five subjects underwent a series of symmetric or asymmetric oscillations and reported their perceived head orientation at the end using landmarks in the testing room; this was converted into total position error (TPE). Thirty-two channel EEG was recorded before, during and after adaptation. Spectral power and coherence were calculated for the alpha, beta, delta and theta frequency bands. Linear mixed models were used to determine a region-by-condition effect of the adaptation. TPE was significantly greater in the asymmetric condition and reported error was always in the direction of the FHC. Regardless of condition, alpha desynchronised in response to stimulation, then rebounded back toward baseline values. This pattern was accelerated and attenuated in the prefrontal and occipital regions, respectively, in the asymmetric condition. Functional connectivity networks were identified in the beta and delta frequency bands; these networks, primarily comprising frontoparietal connections, were more coherent during asymmetric stimulation. These findings suggest that the temporary vestibulo-perceptual 'neglect' induced by asymmetric vestibular stimulation may be mediated by alpha rhythms and frontoparietal attentional networks. The results presented further our understanding of brain rhythms and cortical networks involved in vestibular perception and adaptation. KEY POINTS: Whole-body asymmetric sinusoidal oscillations, which consist of hemicycles with equal amplitude but differing velocities, can induce transient 'neglect' of the slower hemicycle in the vestibular perception of healthy subjects. In this study, we aimed to elucidate EEG correlates of this 'neglect', thereby identifying a cortical role in vestibular perception and adaptation. We identified a desynchronisation-resynchronisation response in the alpha frequency band (8-14 Hz) that was accelerated in the prefrontal region and attenuated in the occipital region when exposed to asymmetric, as compared to symmetric, rotations. We additionally identified functional connectivity networks in the beta (14-30 Hz) and delta (1-4 Hz) frequency bands consisting primarily of frontoparietal connections. These results suggest a prominent role of alpha rhythms and frontoparietal attentional networks in vestibular perception and adaptation.
Assuntos
Reflexo Vestíbulo-Ocular , Vestíbulo do Labirinto , Adaptação Fisiológica/fisiologia , Eletroencefalografia , Humanos , Percepção , Reflexo Vestíbulo-Ocular/fisiologia , Vestíbulo do Labirinto/fisiologiaRESUMO
ABSTRACT Purpose: to describe at which age do speech and language therapists consider the / l /, / ɾ /, / r / phonemes should be acquired; to describe the criteria used by speech and language therapists to consider a phoneme as acquired; and to investigate the diagnostic criteria used by these professionals. Methods: this is an analytical cross-sectional study in which an online questionnaire was completed by 151 speech and language therapists from the Metropolitan region of Chile. The questionnaire included questions regarding the aims of this study. Results: around a 30% of respondents considered the /l/ phoneme to be acquired between 3,6-4,6 years, a 72% agreed on the /ɾ/ phoneme to be acquired from 4,0 to 4,11 and a 40% declared the acquisition of the /r/ phoneme between 5,6-5,11. When determining a phoneme as acquired, a 46.3% of interviewees referred to do it only when it was produced always and a 30% declared to consider as such when produced more than 50% of the times. When exposed to a real case, respondents provided three different diagnostic options. Conclusion: results showed a wide age range in which speech and language therapists consider the lateral and rhotic phonemes to be acquired, showing no consensus. There are diverse criteria to determine when each phoneme is acquired. Similarly, different opinions were evidenced regarding when a disorder would be defined as phonologic or articulatory.
RESUMEN Objetivo: describir la edad en que consideran que deben estar adquiridos los fonemas / l /, / ɾ /, / r /; describir el criterio que utilizan fonoaudiólogos para considerar un fonema adquirido; e indagar sobre los criterios diagnósticos que utilizan estos profesionales. Métodos: se realizó un estudio transversal analítico mediante un cuestionario validado, presentado de manera online, a 151 fonoaudiólogos de la Región Metropolitana de Chile, con preguntas referidas a los objetivos presentados. Resultados: aproximadamente un 30% de los encuestados consideró que el fonema /l/ se adquiría entre 3,6-4,6 años, /ɾ/ entre 4,0-4,11 un 72% y /r/ entre 5,6-5,11 un 40%. El 46,3% considera que un fonema está adquirido cuando se dice siempre y un 30% cuando lo dice más del 50% de las veces. Ante el relato de un caso, los encuestados eligieron tres opciones diagnósticas diferentes Conclusión: se observa que existe una amplia variedad de rango etario en la que los fonoaudiólogos creen que deben adquirirse los fonemas lateral y róticos no encontrándose un consenso. Existe una alta variedad de criterios respecto a cuándo considerar un fonema como adquirido. También existen distintas concepciones sobre cuándo un trastorno se considerará articulatorio o fonológico.
RESUMO
ABSTRACT Aim: to characterize the health or education centers that work with deaf children from an early age. Methods: a survey of those in charge of centers for people with hearing loss (N=5), special schools for the deaf (N=3) and hospitals in which therapeutic intervention for people with hearing impairments (N=6) was carried out in Santiago, Chile in 2014. It consulted the characteristics of the people attended, the intervention method used at each center and information about the professionals making up each team of workers. In addition, information was compiled about whether the institution had inclusion programmes for normal or special education. Results: the majority of the institutions indicated that they had an oral focus or a variation on this. Only one used the bilingual intercultural model and another indicated that did not use oral models. The results varied concerning access to education and even to professionals, at centers of the same kind. Conclusion: the majority of the institutions indicated that they worked using the oral intervention methodology, providing fewer options for the early inclusion of bilingual intercultural education or other intervention methodologies.
RESUMEN Objetivo: caracterizar a los centros de Salud o Educación que trabajan con niños sordos a temprana edad. Métodos: se ejecutó un cuestionario a encargados de centros de atención de personas con hipoacusia(N=5), escuelas especiales de sordos (N=3) y hospitales en los que se realizaba intervención terapéutica en personas con discapacidad auditiva (N=6) en Santiago, Chile, durante 2014. Se consultó sobre características de usuarios atendidos, método de intervención adscrito en cada centro, e información de profesionales que conformaban cada equipo de trabajo. Además, se recogió información acerca de si la institución contaba con programas de inclusión en educación regular o especial. Resultados: las instituciones mayoritariamente declararon seguir un enfoque oral o variantes de este. Sólo uno adscribe al modelo intercultural bilingüe, y otro señala no considerar modelos orales. Existe variabilidad de resultados en torno a acceso a la educación y profesionales incluso en centros del mismo tipo. Concusión: la mayoría de las instituciones expresó trabajar bajo la metodología de intervención oral, dejando pocas opciones a la inserción temprana de educación intercultural bilingüe u otra metodología de intervención.
