It is hypothesized that repeated, non‐invasive stimulation of the vestibular (balance) system, via a small electrical current to the skin behind the ears, will cause the brain centers that control energy homeostasis to shift the body toward a leaner physique. This is because these centers integrate multiple inputs to, in effect, fix a set‐point for body fat, which though difficult to alter is not immutable. They will interpret repeated stimulation of the parts of the vestibular system that detect (...) acceleration as a state of chronic activity. During such a physiologically challenging time it is preferable, from an energy homeostasis viewpoint, to both utilize fat reserves, and reduce the volume of these reserves and thus the energy cost of carrying them around. Hence, this type of vestibular stimulation could potentially be a therapeutic option for metabolic syndrome disorders such as obesity. This hypothesis is eminently testable via a clinical trial. (shrink)

Summary Apotemnophilia, or body integrity image disorder (BIID), is characterised by a feeling of mismatch between the internal feeling of how one’s body should be and the physical reality of how it actually is. Patients with this condition have an often overwhelming desire for an amputation- of a specific limb at a specific level. Such patients are not psychotic or delusional, however, they do express an inexplicable emotional abhorrence to the limb they wish removed. It is also known that such (...) patients show a left-sided preponderance for their desired amputation. Often they take drastic action to be rid of the offending limb. Given the left-sided bias, emotional rejection and specificity of desired amputation, we suggest that there are clear similarities to be drawn between BIID and somatoparaphrenia. In this rare condition, which follows a right parietal stroke, the patient rejects (usually) his left arm as ‘‘alien’’. We go on to hypothesis that a dysfunction of the right parietal lobe is also the cause of BIID. We suggest that this leads to an uncoupling of the construct of one’s body image in the right parietal lobe from how one’s body physically is. This hypothesis would be amenable to testing by response to cold-water vestibular caloric stimulation, which is known to temporarily treat somatoparaphrenia. It could also be investigated using functional brain imaging and skin conductance response. If correct our hypothesis not only suggests why BIID arises, but also, in caloric stimulation a therapeutic avenue for this chronic and essentially untreatable condition. (shrink)

Artificial stimulation of the peripheral vestibular system has been shown to improve ownership of body parts in neurological patients, suggesting vestibular contributions to bodily self-consciousness. Here, we investigated whether galvanic vestibular stimulation interferes with the mechanisms underlying ownership, touch, and the localization of one’s own hand in healthy participants by using the “rubber hand illusion” paradigm. Our results show that left anodal GVS increases illusory ownership of the fake hand and illusory location of touch. We propose that (...) these changes are due to vestibular interference with spatial and/or temporal mechanisms of visual-tactile integration leading to an enhancement of visual capture. As only left anodal GVS lead to such changes, and based on neurological data on body part ownership, we suggest that this vestibular interference is mediated by the right temporo-parietal junction and the posterior insula. (shrink)

For decades, the audiovisual nature of the film medium has limited film scholarship to the strict consideration of sound and sight as the senses at play. Aware of the limitations of this sense-to-sense correspondence, Laura U. Marks has been the first to consistently give expression to a new and emergent line of enquiry that seeks to understand the multisensory nature of film.Adding to the emergent awareness of the cinema of the senses, neuroscience, specifically multisensory studies, has identified autonomous sensory systems (...) beyond the classic five senses: the vestibular (orientation and balance), proprioception (posture and body position), pain, and temperature perception. This essay investigates the principles of the multisensory film experience when applied to our sense of orientation and balance in film – the vestibular in film. Here I seek to outline the neural and physiological evidence supporting the idea that we can have access to the multisensory exclusively through sound and image, based on the nature of our perception and cognition.I then apply this frame of reference to a new understanding of Gus Van Sant’s cinema of walking composed by the so-called death trilogy of Gerry (2002), Elephant (2003) and Last Days (2005) plus Paranoid Park (2007). With this analysis I show how the vestibular sense can be a powerful aesthetic and cinematic mode of filmmaking, as well revealing of the sensuous nature of film. (shrink)

Objective: Caloric vestibular stimulation has traditionally been used as a tool for neurological diagnosis. More recently, however, it has been applied to a range of phenomena within the cognitive neurosciences. Here, we provide an overview of such studies and review our work using CVS to investigate the neural mechanisms of a visual phenomenon - binocular rivalry. We outline the interhemispheric switch model of rivalry supported by this work and its extension to a metarivalry model of interocular-grouping phenomena. In addition, (...) studies showing a slow rate of binocular rivalry in bipolar disorder are discussed, and the relationship between this finding and the interhemispheric switch model is described. We also review the effects of CVS in various clinical contexts, explain how the technique is performed and discuss methodological issues in its application. (shrink)

Galvanic vestibular stimulation is a non-invasive method of electrically stimulating the vestibular system. We investigated whether the application of GVS can alter the learning of new functional mobility and manual control tasks and whether learning can be retained following GVS application. In a between-subjects experiment design, 36 healthy subjects performed repeated trials, capturing the learning of either a functional mobility task, navigating an obstacle course on a compliant surface with degraded visual cues or a manual control task, using (...) a joystick to null self-roll tilt against a pseudo-random disturbance while seated in the dark. In the “learning” phase of trials, bilateral, bipolar GVS was applied continuously. The GVS waveform also differed between subjects in each task group: white noisy galvanic vestibular stimulation at 0.3 mA high-level random GVS at 0.7 mA, or with the absence of stimulation. Following the “learning” trials, all subjects were blindly transitioned to sham GVS, upon which they immediately completed another series of trials to assess any aftereffects. In the functional mobility task, we found nGVS significantly improved task learning. Further, improvements in learning the functional mobility task with nGVS were retained, even once the GVS application was stopped. The benefits in learning with nGVS were not observed in the manual control task. High level GVS tended to inhibit learning in both tasks, but not significantly so. Even once the high-level stimulation was stopped, the impaired performance remained. Improvements in learning with nGVS may be due to increased information throughput resulting from stochastic resonance. The benefit of nGVS for functional mobility, but not manual control nulling, may be due to the multisensory, strategic, motor coordination, or spatial awareness aspects of the former task. Learning improvements with nGVS have the potential to benefit individuals who perform functional mobility tasks, such as astronauts, firefighters, high performance athletes, and soldiers. (shrink)

The visual system is a source of sensory information that perceives environmental stimuli and interacts with other sensory systems to generate visual and postural responses to maintain postural stability. Although the three sensory systems; the visual, vestibular, and somatosensory systems work concurrently to maintain postural control, the visual and vestibular system interaction is vital to differentiate self-motion from external motion to maintain postural stability. The visual system influences postural control playing a key role in perceiving information required for (...) this differentiation. The visual system’s main afferent information consists of optic flow and retinal slip that lead to the generation of visual and postural responses. Visual fixations generated by the visual system interact with the afferent information and the vestibular system to maintain visual and postural stability. This review synthesizes the roles of the visual system and their interaction with the vestibular system, to maintain postural stability. (shrink)

The vestibular system encodes motion and orientation of the head in space and is essential for negotiating in and interacting with the world. Recently, random waveform electric vestibular stimulation has become an increasingly common means of probing the vestibular system. However, many of the methods used to analyze the behavioral response to this type of stimulation assume a linear relationship between frequencies in the stimulus and its associated response. Here we examine this stimulus-response frequency linearity to determine (...) the validity of this assumption. Forty-five university-aged subjects stood on a force-plate for 4 min while receiving vestibular stimulation. To determine the linearity of the stimulus-response relationship we calculated the cross-frequency power coupling between a 0 and 25 Hz bandwidth limited white noise stimulus and induced postural responses, as measured using the horizontal forces acting at the feet. Ultimately, we found that, on average, the postural response to a random stimulus is linear across stimulation frequencies. This result supports the use of analysis methods that depend on the assumption of stimulus-response frequency linearity, such as coherence and gain, which are commonly used to analyze the body’s response to random waveform electric stimuli. (shrink)

Em trabalhos anteriores, analisamos as formas pelas quais a sociologia vem sendo cobrada nos vestibulares de algumas universidades em diferentes regiões brasileiras e no ENEM. Além do entendimento de que formas são essas, uma das conclusões a que chegamos foi a de que, no ENEM, dificilmente há o acionamento de conhecimento sociológico prévio para a resolução da prova. Entendemos que, por mais que a cobrança na redação e de modo interdisciplinar traga algum reconhecimento ao saber sociológico, a construção de questões (...) que possam ir além da interpretação de texto é fundamental para a consolidação da sociologia no exame. Sendo assim, como continuidade de nossa reflexão, objetivamos, no presente trabalho, discutir, afinal, o que é esse conhecimento prévio, que pode ser entendido como conceitos, temas e teorias sociológicos. Mas quais são eles e como são cobrados na prática? Como sabemos, não há uma definição nacional dos conteúdos da sociologia, mas algumas propostas estaduais. Analisaremos quais são, segundo os editais das universidades, as matérias de sociologia presentes em alguns vestibulares, se é possível chegar a um mapa comum e se esse mapa é compatível ou não com os currículos mínimos estaduais. Para isso, analisaremos editais dos vestibulares em que a sociologia está presente e do ENEM. (shrink)

ObjectiveNoisy galvanic vestibular stimulation (nGVS) is often used to improve postural stability in disorders, such as neurorehabilitation montage. For the safe use of nGVS, we investigated whether arterial pressure (AP) and heart rate vary during static supine and slow whole-body tilt with random nGVS (0.4 mA, 0.1–640 Hz, gaussian distribution) in a healthy elderly population.MethodsThis study was conducted with a double-blind, sham-controlled, cross-over design. Seventeen healthy older adults were recruited. They were asked to maintain a static supine position on (...) a bed for 10 min, and the bed was tilted up (TU) to 70 degrees within 30 s. After maintaining this position for 3 min, the bed was passively tilted down (TD) within 30 s. Real-nGVS or sham-nGVS was applied from 4 to 15 min. The time course of mean arterial pressure (MAP) and RR interval variability (RRIV) were analyzed to estimate the autonomic nervous activity.ResultnGVS and/or time, including pre-/post-event (nGVS-start, TU, and TD), had no impact on MAP and RRIV-related parameters. Further, there was no evidence supporting the argument that nGVS induces pain, vertigo/dizziness, and uncomfortable feeling.ConclusionnGVS may not affect the AP and RRIV during static position and whole-body tilting or cause pain, vertigo/dizziness, and discomfort in the elderly. (shrink)

Postural instability and balance impairment are disabling symptoms in patients with acute unilateral peripheral vestibular hypofunction. Vestibular rehabilitation is known to improve the vestibular compensation process, but its effect on posture recovery remains poorly understood, little is known about when VR must be done, and whether the degree of vestibular loss matters is uncertain. We analyzed posture control under static and dynamic postural tasks performed in different visual conditions [eye open ; eyes closed ; and optokinetic (...) stimulation] using dynamic posturography. Non-linear analyses of the postural performance were performed in two groups of patients with UVH subjected to the same VR program based on the unidirectional rotation paradigm and performed either early or later after vertigo attack. Distribution of the angular horizontal vestibulo-ocular reflex gain values recorded on the hypofunction side before rehabilitation differentiated two distinct sub-groups with aVOR gains below or above 0.20. The postural performance of the four sub-groups of patients with UVH tested before VR showed significantly altered postural parameters compared with healthy controls. Greater instability, higher energy to control posture, larger sway without feedback corrections, and lower time of automatic control of posture were observed in static conditions. The four sub-groups recovered near-normal postural performance after VR in the EO and EC conditions, but still exhibited altered postural performance with optokinetic stimulation. In dynamic posturography conditions and before VR, the percentage of patients able to perform the postural tasks with EC and optokinetic stimulation was significantly lower in the two sub-groups with aVOR gain <0.20. After VR, the improvement of the postural parameters depended on the stage of rehabilitation and the degree of vestibular hypofunction. The best balance function recovery was found in the sub-group with early VR and pre-rehabilitation aVOR gain above 0.20, the worst in the sub-group with late rehabilitation and aVOR gain below 0.20. These differences were seen when the vestibular input remains the main sensory cue to control balance, that is, on unstable support without vision or altered visual motion cues. These findings extend to dynamic balance recovery the crucial roles of early rehabilitation and degree of vestibular hypofunction which we have already highlighted for vestibulo-ocular reflex recovery. (shrink)

Objective: This study aimed to investigate whether galvanic vestibular stimulation with stochastic noise modulates the body sway and muscle activity of the lower limbs, depending on visual and somatosensory information from the foot using rubber-foam.Methods: Seventeen healthy young adults participated in the study. Each subject maintained an upright standing position on a force plate with/without rubber-foam, with their eyes open/closed, to measure the position of their foot center of pressure. Thirty minutes after baseline measurements under four possible conditions performed (...) without nGVS, the stimulation trials were conducted under the same conditions in random order, which were then repeated a week or more later. The total center of pressure path length movement and COP movement velocity in the mediolateral and anteroposterior directions were recorded for 30 s during nGVS. Furthermore, electromyography activity of the right tibial anterior muscle and soleus muscle was recorded for the same time and analyzed.Results: Three-way analysis of variance and post-hoc multiple comparison revealed a significant increment in COP-related parameters by nGVS, and a significant increment in soleus muscle activity on rubber. There was no significant effect of eye condition on any parameter.Conclusions: During nGVS, body sway and muscle activity in the lower limb may be increased depending not on the visual condition, but on the foot somatosensory condition. (shrink)

Falls are frequent in Myotonic Dystrophy type 1, but the pathophysiology of the balance impairment needs further exploration in this disease. The current work aims to provide a richer understanding of DM1 imbalance. Standing balance in 16 patients and 40 controls was tested in two posturographic tests. In the Sensory Organization Test, standstill balance was challenged by combining visual and environmental conditions. In the “react” test, reflexes induced by sudden shifts in the support base were studied. Oscillations of the body (...) centre of mass were measured. In the SOT, COM sway was larger in patients than controls in any condition, including firm support with eyes open. On sway-tuned support, COM oscillations when standing with closed eyes were larger in patients than controls even after taking into account the oscillations with eyes open. In the “react” paradigm, balance reflexes were delayed in patients. Results in both experimental paradigms are consistent with leg muscle weakness. This, however, is not a sufficient explanation. The SOT test highlighted that patients rely on vision more than controls to maintain static balance. Consistently enough, evidence is provided that an impairment of proprioceptive and vestibular systems contributes to falls in DM1. Rehabilitation programs targeted at reweighting sensory systems may be designed to improve safe mobility in DM1. (shrink)

Os atuais documentos oficiais elaborados pelo Ministério da Educação no Brasil têm preconizado o ensino da produção textual por meio do gênero -discursivo ou textual. Seguindo essa linha, o exame vestibular de ingresso a uma das maiores universidades paulistas de 2011 também solicitou dos candidatos a elaboração de três textos, de diferentes gêneros. Com o objetivo de verificar que horizontes teórico-metodológicos fundamentaram a elaboração daquele exame, analisamos os textos do Manual do Candidato, da Prova de redação e da Expectativa (...) da banca. Nosso parâmetro teórico é o conceito de gênero discursivo conforme desenvolvido pelos membros do Círculo de Bakhtin desde 1920. Observamos, então, como essa nova proposta visa avaliar as características que a Universidade espera encontrar em cada um de seus alunos; como utiliza o arsenal teórico nos textos analisados e como garante a avaliação da capacidade argumentativa dos candidatos. Finalmente, sugerimos a possibilidade de trabalho com o gênero "dissertação escolar".Today's official documents drawn up by the Ministry of Education in Brazil have advocated that textual production should be taught by the concepts of speech genre or textual genre. Following this guideline, the 2011 edition of the entrance exam, vestibular, of one of the most important universities in the state of São Paulo, Brazil, asked its candidates to write three texts, each one belonging to a different genre. In order to verify the theoretical-methodological horizons that motivated the elaboration of that exam, we analyzed the texts of the candidate's guidelines, the examination essay and the expectations set by the examiners. Our theoretical perspective is the concept of discursive genre as developed by the members of the Bakhtin Circle since 1920. Then, we observe how this new proposal aims at evaluating the characteristics that the University expects to find in each one of its students; how the theoretical perspectives are used in the analyzed texts and how the assessment of the candidates' argumentative ability is ensured. Finally, we suggest the possibility of working with the genre "scholar essay". (shrink)