RESUMO
Purpose: To demonstrate the effect of an orofacial myofunctional therapy intervention by an interdisciplinary team composed of a registered dental hygienist who is also a certified orofacial myologist (COM®), a general dentist, and an orthodontist on the elimination of oral habits and changes in dental malocclusion. Method: This case study describes a 7-year-old female who underwent an individualized myofunctional therapy program and was given supervised education on a series of exercises targeting the muscles of mastication and facial expression over 5 months. Correct oral rest postures of the tongue and the lips were also established through therapy. Results: The intervention enabled the client to eliminate multiple oral habits, which corrected oral rest postures of the lips and tongue. This correction consequently improved the client's malocclusion and further prepared the client for future orthodontic treatment. Conclusion: Myofunctional therapy facilitated the elimination of unfavourable oral habits that led to malocclusion. Eliminating oral habits better prepared the client for orthodontic treatment and retention. Use of an interdisciplinary team facilitates optimal client care.
Objectif: Démontrer l'effet d'une thérapie orofaciale myofonctionnelle par une équipe interdisciplinaire composée d'un hygiéniste dentaire autorisé qui est aussi un myologiste orofacial certifié (COM®), d'un dentiste généraliste et d'un orthodontiste sur l'élimination des habitudes buccales et les changements de la malocclusion dentaire. Méthodologie: La présente étude de cas décrit une fille de 7 ans qui a suivi un programme personnalisé de thérapie myofonctionnelle et a reçu une éducation supervisée sur une série d'exercices ciblant les muscles de la mastication et de l'expression faciale au cours d'une période de 5 mois. La thérapie a aussi permis d'établir des postures appropriées de repos de la langue et des lèvres. Résultats: Grâce à la thérapie, la cliente a pu éliminer de multiples habitudes buccales, ce qui a corrigé les postures de repos buccal des lèvres et de la langue. Cette modification a par conséquent amélioré la malocclusion de la cliente et a permis de la préparer à un futur traitement orthodontique. Conclusion: La thérapie myofonctionnelle a favorisé l'élimination d'habitudes buccales défavorables qui ont mené à la malocclusion. En éliminant les habitudes buccales, la cliente était mieux préparée au traitement orthodontique et à la rétention. L'utilisation d'une équipe interdisciplinaire optimise les soins du client.
Assuntos
Má Oclusão , Terapia Miofuncional , Feminino , Humanos , Criança , Má Oclusão/terapia , Músculos Faciais/fisiologia , Língua/fisiologia , Hábitos Linguais/terapiaRESUMO
BACKGROUND: Analysis of the reactions of different organs to external stimuli is an important area of research in physiological science. OBJECTIVE: In this paper, we investigated the correlation between the brain and facial muscle activities by information-based analysis of electroencephalogram (EEG) signals and electromyogram (EMG) signals using Shannon entropy. METHOD: The EEG and EMG signals of thirteen subjects were recorded during rest and auditory stimulations using relaxing, pop, and rock music. Accordingly, we calculated the Shannon entropy of these signals. RESULTS: The results showed that rock music has a greater effect on the information of EEG and EMG signals than pop music, which itself has a greater effect than relaxing music. Furthermore, a strong correlation (r= 0.9980) was found between the variations of the information of EEG and EMG signals. CONCLUSION: The activities of the facial muscle and brain are correlated in different conditions. This technique can be utilized to investigate the correlation between the activities of different organs versus brain activity in different situations.
Assuntos
Eletroencefalografia , Músculos Faciais , Estimulação Acústica , Encéfalo/fisiologia , Eletroencefalografia/métodos , Eletromiografia/métodos , Músculos Faciais/fisiologia , HumanosRESUMO
While there is an increasing shift in cognitive science to study perception of naturalistic stimuli, this study extends this goal to naturalistic contexts by assessing physiological synchrony across audience members in a concert setting. Cardiorespiratory, skin conductance, and facial muscle responses were measured from participants attending live string quintet performances of full-length works from Viennese Classical, Contemporary, and Romantic styles. The concert was repeated on three consecutive days with different audiences. Using inter-subject correlation (ISC) to identify reliable responses to music, we found that highly correlated responses depicted typical signatures of physiological arousal. By relating physiological ISC to quantitative values of music features, logistic regressions revealed that high physiological synchrony was consistently predicted by faster tempi (which had higher ratings of arousing emotions and engagement), but only in Classical and Romantic styles (rated as familiar) and not the Contemporary style (rated as unfamiliar). Additionally, highly synchronised responses across all three concert audiences occurred during important structural moments in the music-identified using music theoretical analysis-namely at transitional passages, boundaries, and phrase repetitions. Overall, our results show that specific music features induce similar physiological responses across audience members in a concert context, which are linked to arousal, engagement, and familiarity.
Assuntos
Nível de Alerta/fisiologia , Percepção Auditiva/fisiologia , Emoções/fisiologia , Músculos Faciais/fisiologia , Frequência Cardíaca/fisiologia , Música/psicologia , Reconhecimento Psicológico/fisiologia , Taxa Respiratória/fisiologia , Estimulação Acústica/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Cross-modal integration is ubiquitous within perception and, in humans, the McGurk effect demonstrates that seeing a person articulating speech can change what we hear into a new auditory percept. It remains unclear whether cross-modal integration of sight and sound generalizes to other visible vocal articulations like those made by singers. We surmise that perceptual integrative effects should involve music deeply, since there is ample indeterminacy and variability in its auditory signals. We show that switching videos of sung musical intervals changes systematically the estimated distance between two notes of a musical interval so that pairing the video of a smaller sung interval to a relatively larger auditory led to compression effects on rated intervals, whereas the reverse led to a stretching effect. In addition, after seeing a visually switched video of an equally-tempered sung interval and then hearing the same interval played on the piano, the two intervals were judged often different though they differed only in instrument. These findings reveal spontaneous, cross-modal, integration of vocal sounds and clearly indicate that strong integration of sound and sight can occur beyond the articulations of natural speech.
Assuntos
Percepção Auditiva/fisiologia , Músculos Faciais/fisiologia , Movimento/fisiologia , Música/psicologia , Canto/fisiologia , Som , Voz/fisiologia , Estimulação Acústica/métodos , Adolescente , Adulto , Feminino , Audição/fisiologia , Humanos , Masculino , Fala , Percepção da Fala/fisiologia , Estudantes/psicologia , Adulto JovemRESUMO
OBJECTIVES: The main objective of this study was to analyze differences on pain pressure thresholds, tongue strength and perceived effort between various orofacial motor exercise training dosages of mental representation training through motor imagery (MI) and action observation (AO), first in isolation and then in combination with real exercise performance. METHODS: A single-blind randomized controlled trial was designed. 48 asymptomatic individuals were randomized into two groups: Intensive training group (IG) and Moderate training group (MG). Both groups performed a first session of MI and AO of orofacial exercises training and a second session of actual orofacial exercises combined with mental representation training, but with different dosage in terms of series and repetitions. Pain pressure thresholds (PPTs) in the masseter and temporal muscles and tongue muscle strength were the main variables. RESULTS: Regarding the PPT, ANOVA revealed significant between-group differences, where MG showed a significantly higher PPT than IG at post-day2, with a medium effect size. Both groups showed with-in group differences between pre and post intervention measures in the first session, but only the IG showed differences in the second. Regarding tongue muscle strength, ANOVA revealed significant within-group differences only in MG between the pre-day and post-day first intervention. CONCLUSION: The results of the present study suggest that movement representation training performed in isolation may have a positive effect on PPTs and tongue muscle strength. In addition, the combination with the actual execution of the exercises could be considered effective, but it is necessary to take into account the training dosage to avoid fatigue responses.
Assuntos
Exercício Físico/fisiologia , Músculos Faciais/fisiologia , Força Muscular/fisiologia , Percepção da Dor/fisiologia , Língua/fisiologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Imagens, Psicoterapia , Imaginação , Masculino , Músculo Masseter/fisiologia , Pessoa de Meia-Idade , Fadiga Muscular , Limiar da Dor , Pressão , Método Simples-Cego , Músculo Temporal/fisiologia , Adulto JovemRESUMO
Reanimation of paralysed facial muscles by electrical stimulation has been studied extensively in animal models, but human studies in this field are largely lacking. Twenty-four subjects with a peripheral facial nerve palsy with a median duration of three years were enrolled. We studied activations of four facial muscles with electrical stimulation using surface electrodes. In subjects whose voluntary movement was severely impaired or completely absent, the electrical stimulation produced a movement that was greater in amplitude compared with the voluntary effort in 10 out of 18 subjects in the frontalis muscle, in 5 out of 14 subjects in the zygomaticus major muscle, and in 3 out of 8 subjects in the orbicularis oris muscle. The electrical stimulation produced a stronger blink in 8 subjects out of 22 compared with their spontaneous blinks. The stimulation could produce a better movement even in cases where the muscles were clinically completely paretic, sometimes also in palsies that were several years old, provided that the muscle was not totally denervated. Restoring the function of paralysed facial muscles by electrical stimulation has potential as a therapeutic option in cases where the muscle is clinically paretic but has reinnervation.
Assuntos
Músculos Faciais/fisiologia , Paralisia Facial/reabilitação , Estimulação Elétrica Nervosa Transcutânea , Adulto , Idoso , Piscadela/fisiologia , Músculos Faciais/inervação , Nervo Facial/fisiologia , Nervo Facial/fisiopatologia , Paralisia Facial/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Regeneração Nervosa , Resultado do Tratamento , Adulto JovemRESUMO
Little is known about how proprioceptive signals arising from muscles reach to higher brain regions such as the cerebral cortex. We have recently shown that a particular thalamic region, the caudo-ventromedial edge (VPMcvm) of ventral posteromedial thalamic nucleus (VPM), receives the proprioceptive signals from jaw-closing muscle spindles (JCMSs) in rats. In this study, we further addressed how the orofacial thalamic inputs from the JCMSs were transmitted from the thalamus (VPMcvm) to the cerebral cortex in rats. Injections of a retrograde and anterograde neuronal tracer, wheat-germ agglutinin-conjugated horseradish peroxidase (WGA-HRP), into the VPMcvm demonstrated that the thalamic pathway terminated mainly in a rostrocaudally narrow area in the dorsal part of granular insular cortex rostroventrally adjacent to the rostralmost part of the secondary somatosensory cortex (dGIrvs2). We also electrophysiologically confirmed that the dGIrvs2 received the proprioceptive inputs from JCMSs. To support the anatomical evidence of the VPMcvm-dGIrvs2 pathway, injections of a retrograde neuronal tracer Fluorogold into the dGIrvs2 demonstrated that the thalamic neurons projecting to the dGIrvs2 were confined in the VPMcvm and the parvicellular part of ventral posterior nucleus. In contrast, WGA-HRP injections into the lingual nerve area of core VPM demonstrated that axon terminals were mainly labeled in the core regions of the primary and secondary somatosensory cortices, which were far from the dGIrvs2. These results suggest that the dGIrvs2 is a specialized cortical region receiving the orofacial proprioceptive inputs. Functional contribution of the revealed JCMSs-VPMcvm-dGIrvs2 pathway to Tourette syndrome is also discussed.
Assuntos
Córtex Cerebral/fisiologia , Músculos Faciais/inervação , Vias Neurais/fisiologia , Propriocepção/fisiologia , Tálamo/fisiologia , Animais , Mapeamento Encefálico , Estimulação Elétrica , Potenciais Evocados/fisiologia , Músculos Faciais/fisiologia , Lateralidade Funcional , Arcada Osseodentária/fisiologia , Masculino , Ratos , Ratos Wistar , Conjugado Aglutinina do Germe de Trigo-Peroxidase do Rábano Silvestre/metabolismoRESUMO
Neuromuscular electrical stimulation (NMES) may have potential as a treatment for muscle weakness as it may improve strength when applied to the orofacial muscles. However, before incorporating this procedure into clinical practice, research is needed to investigate its effects on lingual and facial muscles of speech and mastication. The aim of this study was to determine what effect(s) submental and labial NMES would have on lingual and labial muscle strength in healthy participants. Fourteen healthy adults (27-49 years old) were assigned to two groups (treatment and control). A pretreatment and post-treatment test using the Iowa Oral Performance Instrument was used to measure the strength of labial and lingual muscles in both groups. Participants in the treatment group received labial and submental NMES while performing a structured labial, buccal, and lingual exercise program. In contrast, participants in the control group completed the same oral motor exercise program without stimulation. RESULTS: On comparing the total change in labial and lingual strength between the two groups, an increase in total labial strength was found in the treatment group compared with the control group. However, the control group showed an increase in total lingual strength compared with the treatment group. Results for all measurements were not statistically significant. This study concluded that NMES may be a promising modality to combine with labial and buccal exercises for improvement of muscle strength.
Assuntos
Terapia por Estimulação Elétrica , Músculos Faciais/fisiologia , Músculos da Mastigação/fisiologia , Força Muscular/fisiologia , Adulto , Feminino , Voluntários Saudáveis , Humanos , MasculinoRESUMO
PURPOSE: We aimed to evaluate the reliability and reproducibility of repetitive nerve stimulation recorded on occipitalis muscle by comparing recordings on nasalis muscle in healthy subjects. METHODS: A total of 23 healthy subjects (mean age: 44.7 ± 13.8 years) underwent detailed neurological examination and repetitive nerve stimulation using nasalis and occipitalis muscles. Amplitude and area percentage changes of compound muscle action potentials (CMAPs) after repetitive nerve stimulation with different frequency were compared between right and left sides and between recordings on nasalis and occipitalis muscles. RESULTS: Comparisons of percentage amplitude changes of nasalis and occipitalis CMAPs showed no differences (+0.1% ± 3.8% vs. +1.4% ± 3.9%, P = 0.129). Average area percentage change of nasalis CMAPs was 0.3% ± 19.0%, whereas the value of occipitalis CMAP was +2.8% ± 15.2% (P = 0.851). Comparisons of nasalis and occipitalis CMAPs values showed no differences. CONCLUSIONS: The repetitive nerve stimulation recorded on occipitalis muscle is simple, easy to apply, noninvasive, consistent, and reproducible.
Assuntos
Potenciais de Ação/fisiologia , Eletromiografia/normas , Músculos Faciais/fisiologia , Nervo Facial/fisiologia , Couro Cabeludo/fisiologia , Estimulação Elétrica Nervosa Transcutânea/normas , Adulto , Eletromiografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estimulação Elétrica Nervosa Transcutânea/métodosRESUMO
Excitability of articulatory motor cortex is facilitated when listening to speech in challenging conditions. Beyond this, however, we have little knowledge of what listener-specific and speech-specific factors engage articulatory facilitation during speech perception. For example, it is unknown whether speech motor activity is independent or dependent on the form of distortion in the speech signal. It is also unknown if speech motor facilitation is moderated by hearing ability. We investigated these questions in two experiments. We applied transcranial magnetic stimulation (TMS) to the lip area of primary motor cortex (M1) in young, normally hearing participants to test if lip M1 is sensitive to the quality (Experiment 1) or quantity (Experiment 2) of distortion in the speech signal, and if lip M1 facilitation relates to the hearing ability of the listener. Experiment 1 found that lip motor evoked potentials (MEPs) were larger during perception of motor-distorted speech that had been produced using a tongue depressor, and during perception of speech presented in background noise, relative to natural speech in quiet. Experiment 2 did not find evidence of motor system facilitation when speech was presented in noise at signal-to-noise ratios where speech intelligibility was at 50% or 75%, which were significantly less severe noise levels than used in Experiment 1. However, there was a significant interaction between noise condition and hearing ability, which indicated that when speech stimuli were correctly classified at 50%, speech motor facilitation was observed in individuals with better hearing, whereas individuals with relatively worse but still normal hearing showed more activation during perception of clear speech. These findings indicate that the motor system may be sensitive to the quantity, but not quality, of degradation in the speech signal. Data support the notion that motor cortex complements auditory cortex during speech perception, and point to a role for the motor cortex in compensating for differences in hearing ability.
Assuntos
Lábio/fisiologia , Córtex Motor/fisiologia , Percepção da Fala/fisiologia , Fala/fisiologia , Estimulação Acústica/métodos , Adolescente , Adulto , Eletromiografia , Potencial Evocado Motor , Músculos Faciais/fisiologia , Feminino , Testes Auditivos , Humanos , Modelos Lineares , Masculino , Estimulação Magnética Transcraniana , Adulto JovemRESUMO
BACKGROUND/PURPOSE: Photograph-based visual scoring has been used for evaluation of facial morphological changes. Here, we describe a three-dimensional computed tomography (3D-CT) method for objective analysis of facial and intra-facial (subcutaneous) changes. The effects of facial massage were examined using both methods. METHODS: Subjects were 12 healthy female volunteers without facial scars or deformation (age 30-54 years, mean 39.4 years). Photograph-based scoring of massage-induced morphological changes was done at the nasolabial folds, upper, lower and lateral cheeks and lower eyelids. For 3D-CT evaluation, the virtual center axis (VCA) was set as the cranio-caudal longitudinal line, and the VCA-skin surface distances (VSDs) were measured. Massage-induced changes of VSD were calculated (facial massage-induced change rate, FMCR). Intra-facial (subcutaneous) changes were also evaluated. RESULTS: Photograph-based scoring revealed marked morphological changes of the nasolabial folds after facial massage, and changes of the lower, upper and lateral cheeks and lower eyelid were also observed in more than half of the subjects. FMCR values were significantly changed in the paranasal area, nasolabial fold area and cranial part of the mandibular area. Photograph-based scores at the lower cheek and lower eyelid were well correlated with FMCR in the inferior part of the nasolabial fold and the mandibular area, respectively. Massage-induced changes of subcutaneous fat tissues and facial expression muscles were also apparent on CT images. CONCLUSION: 3D-CT imaging is useful for objective evaluation of the effects of facial massage, including anatomical changes in subcutaneous structures.
Assuntos
Face/anatomia & histologia , Face/diagnóstico por imagem , Massagem/efeitos adversos , Tomografia Computadorizada por Raios X/métodos , Adulto , Povo Asiático/etnologia , Bochecha/anatomia & histologia , Bochecha/diagnóstico por imagem , Músculos Faciais/anatomia & histologia , Músculos Faciais/fisiologia , Feminino , Humanos , Imageamento Tridimensional , Massagem/métodos , Pessoa de Meia-Idade , Sulco Nasogeniano/anatomia & histologia , Sulco Nasogeniano/diagnóstico por imagem , Fotografação/métodos , Tela Subcutânea/anatomia & histologia , Tela Subcutânea/diagnóstico por imagemRESUMO
BACKGROUND: The literature on the effects of nocebo on pain is sparse. The present experimental study investigated whether suggestions of nocebo hyperalgesia modified the startle response and whether increased startle contributed to the nocebo hyperalgesic effect. METHODS: A design with four groups was employed; the participants were randomized into either a placebo group, a natural history group, or into two nocebo groups. The participants in the placebo and nocebo groups received suggestions of pain decrease or pain increase, together with a placebo or nocebo cream applied to the lower arm, respectively. Heat pain was induced by a PC-controlled thermode before and after the treatment. White noise was used to elicit startle responses. Startle was assessed by measuring eye blink electromyographic responses recorded from the right orbicularis oculi muscle. RESULTS: The results showed that nocebo suggestions increased reports of pain and startle responses. Increased startle was significantly associated with the nocebo hyperalgesic response. CONCLUSIONS: The results of the present study suggest that verbally induced expectations of increased pain engage cortical physiological defensive systems that in turn mediate the experience of increased pain.
Assuntos
Hiperalgesia/psicologia , Efeito Nocebo , Reflexo de Sobressalto , Estimulação Acústica , Adulto , Eletromiografia , Emoções , Músculos Faciais/fisiologia , Feminino , Temperatura Alta , Humanos , Hiperalgesia/fisiopatologia , Masculino , Percepção da Dor , Reflexo de Sobressalto/fisiologia , Creme para a Pele , Percepção da Fala , Estresse Psicológico , Adulto JovemRESUMO
The mentalis muscle (MM) arises from the incisive fossa of the mandible, raises and protrudes the lower lip. Here, we aim to characterize responses obtained from MM by supraorbital and median electrical as well as auditory stimuli in a group of 16 healthy volunteers who did not have clinical palmomental reflex. Reflex activities were recorded from the MM and orbicularis oculi (O.oc) after supraorbital and median electrical as well as auditory stimuli. Response rates over MM were consistent after each stimulus, however, mean latencies of MM response were longer than O.oc responses by all stimulation modalities. Shapes and amplitudes of responses from O.oc and MM were similar. Based on our findings, we may say that MM motoneurons have connections with trigeminal, vestibulocochlear and lemniscal pathways similar to other facial muscles and electrophysiological recording of MM responses after electrical and auditory stimulation is possible in healthy subjects.
Assuntos
Músculos Faciais/fisiologia , Reflexo/fisiologia , Estimulação Acústica , Idoso , Eletromiografia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Física , Tempo de Reação/fisiologia , Nervo Trigêmeo/fisiologia , Nervo Vestibulococlear/fisiologiaRESUMO
Laughter consists of both motor and emotional aspects. The emotional component, known as mirth, is usually associated with the motor component, namely, bilateral facial movements. Previous electrical cortical stimulation (ES) studies revealed that mirth was associated with the basal temporal cortex, inferior frontal cortex, and medial frontal cortex. Functional neuroimaging implicated a role for the left inferior frontal and bilateral temporal cortices in humor processing. However, the neural origins and pathways linking mirth with facial movements are still unclear. We hereby report two cases with temporal lobe epilepsy undergoing subdural electrode implantation in whom ES of the left basal temporal cortex elicited both mirth and laughter-related facial muscle movements. In one case with normal hippocampus, high-frequency ES consistently caused contralateral facial movement, followed by bilateral facial movements with mirth. In contrast, in another case with hippocampal sclerosis (HS), ES elicited only mirth at low intensity and short duration, and eventually laughter at higher intensity and longer duration. In both cases, the basal temporal language area (BTLA) was located within or adjacent to the cortex where ES produced mirth. In conclusion, the present direct ES study demonstrated that 1) mirth had a close relationship with language function, 2) intact mesial temporal structures were actively engaged in the beginning of facial movements associated with mirth, and 3) these emotion-related facial movements had contralateral dominance.
Assuntos
Terapia por Estimulação Elétrica/métodos , Emoções/fisiologia , Epilepsia do Lobo Temporal/terapia , Riso/fisiologia , Lobo Temporal/fisiologia , Adolescente , Estimulação Elétrica , Eletromiografia , Potencial Evocado Motor/fisiologia , Músculos Faciais/fisiologia , Feminino , Lobo Frontal , Humanos , Idioma , Adulto JovemRESUMO
INTRODUCTION: To study stimulation-related facial electromyographic (FEMG) activity in intensive care unit (ICU) patients, develop an algorithm for quantifying the FEMG activity, and to optimize the algorithm for monitoring the sedation state of ICU patients. METHODS: First, the characteristics of FEMG response patterns related to vocal stimulation of 17 ICU patients were studied. Second, we collected continuous FEMG data from 30 ICU patients. Based on these data, we developed the Responsiveness Index (RI) algorithm that quantifies FEMG responses. Third, we compared the RI values with clinical sedation level assessments and adjusted algorithm parameters for best performance. RESULTS: In patients who produced a clinically observed response to the vocal stimulus, the poststimulus FEMG power was 0.33 µV higher than the prestimulus power. In nonresponding patients, there was no difference. The sensitivity and specificity of the developed RI for detecting deep sedation in the subgroup with low probability of encephalopathy were 0.90 and 0.79, respectively. CONCLUSION: Consistent FEMG patterns were found related to standard stimulation of ICU patients. A simple and robust algorithm was developed and good correlation with clinical sedation scores achieved in the development data.
Assuntos
Estimulação Acústica/métodos , Algoritmos , Eletromiografia/métodos , Músculos Faciais/fisiologia , Unidades de Terapia Intensiva , Monitorização Neurofisiológica , Adulto , Eletromiografia/efeitos dos fármacos , Feminino , Humanos , Hipnóticos e Sedativos/administração & dosagem , Masculino , Pessoa de Meia-Idade , Monitorização Neurofisiológica/métodosRESUMO
High-quality digital sound sources with inaudible high-frequency components (above 20 kHz) have become available because of recent advances in information technology. Listening to such sounds has been shown to increase the α-band power of an electroencephalogram (EEG). The present study scrutinized the time course of this effect by recording EEG along with autonomic measures (skin conductance level and heart rate) and facial electromyograms (corrugator supercilii and zygomaticus major). Twenty university students (19-24 years old) listened to two types of a 200-s musical excerpt (J. S. Bach's French Suite No. 5) with or without inaudible high-frequency components using a double-blind method. They were asked to rate the sound quality and to judge which excerpt contained high-frequency components. High-α EEG power (10.5-13 Hz) was larger for the excerpt with high-frequency components than for the excerpt without them. This effect was statistically significant only in the last quarter of the period (150-200 s). Participants were not able to distinguish between the excerpts, which did not produce any discernible differences in subjective, autonomic, and facial muscle measures. This study shows that inaudible high-frequency components have an impact on human brain activity without conscious awareness. Unlike a standard test for sound quality, at least 150 s of exposure is required to examine this effect in future research.
Assuntos
Estimulação Acústica/psicologia , Ritmo alfa/fisiologia , Encéfalo/fisiologia , Eletroencefalografia/métodos , Música/psicologia , Som , Adulto , Eletromiografia , Músculos Faciais/fisiologia , Feminino , Resposta Galvânica da Pele/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Adulto JovemRESUMO
Heterotopic noxious counter-stimulation (HNCS) is commonly used to study endogenous pain control systems. The resulting pain inhibition is primarily based on spinal cord-brainstem loops. Recently, functional imaging studies have shown that limbic structures like the anterior cingulate cortex and amygdala are also implicated. Since these structures are involved in learning processes, it is possible that the HNCS-induced pain inhibition may depend on specific cues from the environment that have been associated with pain reduction through associative learning. We investigated the influence of Pavlovian conditioning on HNCS-induced pain inhibition in 32 healthy subjects by using a differential conditioning paradigm in which two different acoustic stimuli were either repeatedly paired or unpaired with HNCS. Series of noxious electrical pulse trains delivered to the non-dominant foot served as test stimuli. Diffuse noxious inhibitory control (DNIC)-like effects were induced by concurrent application of tonic HNCS (immersion of the contralateral hand in ice water). Subjective pain intensity and pain unpleasantness ratings and electromyographic recordings of the facial corrugator muscle and the nocifensive RIII flexion reflex were used to measure changes in pain sensitivity. HNCS induced significant pain and reflex inhibitions. In the post-conditioning phase, only the paired auditory cue was able to significantly reduce pain perceptions and corrugator muscle activity. No conditioned effect could be observed in RIII reflex responses. Our results indicate that the functional state of endogenous pain control systems may depend on associative learning processes that, like in the present study, may lead to an attenuation of pain perception. Similar albeit opposite conditioning of pain control mechanisms may significantly be involved in the exacerbation and chronification of pain states.
Assuntos
Estimulação Acústica , Condicionamento Clássico/fisiologia , Nociceptividade , Dor/prevenção & controle , Reflexo/fisiologia , Adolescente , Adulto , Tonsila do Cerebelo/fisiologia , Sinais (Psicologia) , Estimulação Elétrica , Músculos Faciais/fisiologia , Feminino , Giro do Cíngulo/fisiologia , Humanos , Masculino , Inibição Neural/fisiologia , Dor/fisiopatologia , Dor/psicologia , Medição da Dor , Medula Espinal/fisiologiaRESUMO
The purpose of this study was to determine the effect of augmentative visual feedback training on auditory-motor performance. Thirty-two healthy young participants used facial surface electromyography (sEMG) to control a human-machine interface (HMI) for which the output was vowel synthesis. An auditory-only (AO) group (n=16) trained with auditory feedback alone and an auditory-visual (AV) group (n=16) trained with auditory feedback and progressively-removed visual feedback. Subjects participated in three training sessions and one testing session over 3days. During the testing session they were given novel targets to test auditory-motor generalization. We hypothesized that the auditory-visual group would perform better on the novel set of targets than the group that trained with auditory feedback only. Analysis of variance on the percentage of total targets reached indicated a significant interaction between group and session: individuals in the AV group performed significantly better than those in the AO group during early training sessions (while using visual feedback), but no difference was seen between the two groups during later sessions. Results suggest that augmentative visual feedback during training does not improve auditory-motor performance.
Assuntos
Auxiliares de Comunicação para Pessoas com Deficiência , Músculos Faciais/fisiologia , Retroalimentação Sensorial/fisiologia , Neurorretroalimentação/fisiologia , Fonética , Prática Psicológica , Fala/fisiologia , Interface Usuário-Computador , Adolescente , Feminino , Humanos , Masculino , Adulto JovemRESUMO
The purpose of this study was to determine the effect of the addition of binary vibrotactile stimulation to continuous auditory feedback (vowel synthesis) for human-machine interface (HMI) control. Sixteen healthy participants controlled facial surface electromyography to achieve 2-D targets (vowels). Eight participants used only real-time auditory feedback to locate targets whereas the other eight participants were additionally alerted to having achieved targets with confirmatory vibrotactile stimulation at the index finger. All participants trained using their assigned feedback modality (auditory alone or combined auditory and vibrotactile) over three sessions on three days and completed a fourth session on the third day using novel targets to assess generalization. Analyses of variance performed on the 1) percentage of targets reached and 2) percentage of trial time at the target revealed a main effect for feedback modality: participants using combined auditory and vibrotactile feedback performed significantly better than those using auditory feedback alone. No effect was found for session or the interaction of feedback modality and session, indicating a successful generalization to novel targets but lack of improvement over training sessions. Future research is necessary to determine the cognitive cost associated with combined auditory and vibrotactile feedback during HMI control.
Assuntos
Percepção Auditiva/fisiologia , Eletromiografia/métodos , Músculos Faciais/fisiologia , Retroalimentação Sensorial/fisiologia , Sistemas Homem-Máquina , Tato/fisiologia , Biorretroalimentação Psicológica/métodos , Biorretroalimentação Psicológica/fisiologia , Feminino , Humanos , Masculino , Valores de Referência , Análise e Desempenho de Tarefas , Vibração , Adulto JovemRESUMO
Disgust reactions can be elicited using stimuli that engender orogastric rejection (e.g., pus and vomit; core disgust stimuli) but also using images of bloody injuries or medical procedures (e.g., surgeries; blood [body] boundary violation [B-BV] disgust stimuli). These two types of disgust reaction are presumed to be connected by a common evolutionary function of avoiding either food- or blood-borne contaminants. However, reactions to bloody injuries are typically conflated with reactions to the potential pain being experienced by the victim. This may explain why the two forms of "disgust", although similarly communicated (through self-report and facial expressions), evince different patterns of physiological reactivity. Therefore, we tested whether the communicative similarities and physiological dissimilarities would hold when markers of potential contamination in the latter category are removed, leaving only painful injuries that lack blood or explicit body-envelope violations. Participants viewed films that depicted imagery associated with (a) core disgust, (b) painful injuries, or (c) neutral scenes while we measured facial, cardiovascular, and gastric reactivity. Whereas communicative measures (self-report and facial muscles) suggested that participants experienced increased disgust for core disgust and painful injuries, peripheral physiology dissociated the two: core disgust decreased normal gastric activity and painful-injury disgust decelerated heart rate and increased heart rate variability. These findings suggest that expressions of disgust toward bodily injuries may reflect a fundamentally different affective response than those evoked by core disgust and that this (cardiovascularly mediated) response may in fact be more closely tied to pain perceptions (or empathy) rather than contaminant-laden stimuli.