Integrating electrodes to headsets for human-system interaction and psycho-physiological monitoring

Research in human monitoring led to development of powerful tools for users-systems communication via recording electrophysiological data and sending them to the computer system. Eye and gaze tracking are standing as important methods for a broad range of human monitoring applications such as in neuroscience, psychology, industrial engineering, aeronautics, military, and medical expertise. Nowadays, the most used eye-tracking technique is video-based tracking based on infrared illumination. However, the tools using this technique present a certain number of disadvantages. Notably, for the head-mounted tools, such systems obstruct the visual field and therefore are not suitable for integration in real operational environments. An alternative technique is the electro-oculography (EOG) which consists in measuring the standing potential between the front and back of the eyes. This potential increases when the cornea approaches an electrode and it decreases when the cornea moves in the opposite direction. EOG represents one of the easiest methods to estimate eye movements by using low-cost low-energy consumption devices without obstructing the visual field nor handling infrared light. This technique is particularly convenient for the head-mounted peripherals such as audio or virtual reality headsets. Typical features of signal processing, such as the mean of fixation duration, saccadic rates, and blinks are explored in various environments including air traffic control, pilots and co-pilots of civil and military aircraft. Interestingly, the EOG, as well as electroencephalography (EEG) features were correlated to drivers’ and pilots’ workload, drowsiness and fatigue

Effects of verbal encouragement on force and electromyographic activations during exercise.

International audienceBACKGROUND: The aim of the present study was to examine the effects of verbal encouragement on isometric force and associated electromyographic (EMG) parameters during a handgrip task.METHODS: Twenty-three participants (12 women and 11 men) performed maximal voluntary isometric handgrip contractions following three conditions: 1) verbal encouragement (VE) condition: participants executed isometric contractions while being verbally encouraged; 2) non-verbal encouragement (nVE) condition: the same starting and stopping signal but without encouragement; 3) non-concentration and non-motivation (nCM) condition: self-initiated contractions without concentration and motivation. Start and stop of the contraction were self-initiated. The maximal voluntary force (MVF) and the maximal rate of force development (MRFD) were measured. Integrated EMG corresponding to MVF (iEMGMVF) and to MRFD (iEMGMRFD) were collected from flexor digitorum superficialis (FDS) and extensor digitorum communis (EDC) muscles.RESULTS: MVF was higher during VE compared with nVE (+11.7%; P<0.05) and nCM (+23.2%; P<0.05) conditions. Likewise, MRFD was significantly higher during VE, compared with nVE (+21.7%; P<0.05) and nCM (+55.4%; P<0.05) conditions. iEMGMVF increased for FDS and EDC during VE, compared to nVE (+26.19%, +20.5%) and nCM conditions (+68.85%, +48.91%), respectively. iEMGMRFD increased for FDS and EDC during VE, compared to nVE (+21.2%, +46.07%) and nCM conditions (+23.79%, +42.32%). Furthermore, the reproducibility of all these indices was higher with VE condition.CONCLUSIONS: Taken together, force production (MVF and MRFD) and EMG data supported the view that muscles activity is considerably influenced by the verbal encouragements during isometric force exercise

Electro-Encephalography and Electro-Oculography in Aeronautics: A Review Over the Last Decade (2010–2020)

Electro-encephalography (EEG) and electro-oculography (EOG) are methods of electrophysiological monitoring that have potentially fruitful applications in neuroscience, clinical exploration, the aeronautical industry, and other sectors. These methods are often the most straightforward way of evaluating brain oscillations and eye movements, as they use standard laboratory or mobile techniques. This review describes the potential of EEG and EOG systems and the application of these methods in aeronautics. For example, EEG and EOG signals can be used to design brain-computer interfaces (BCI) and to interpret brain activity, such as monitoring the mental state of a pilot in determining their workload. The main objectives of this review are to, (i) offer an in-depth review of literature on the basics of EEG and EOG and their application in aeronautics; (ii) to explore the methodology and trends of research in combined EEG-EOG studies over the last decade; and (iii) to provide methodological guidelines for beginners and experts when applying these methods in environments outside the laboratory, with a particular focus on human factors and aeronautics. The study used databases from scientific, clinical, and neural engineering fields. The review first introduces the characteristics and the application of both EEG and EOG in aeronautics, undertaking a large review of relevant literature, from early to more recent studies. We then built a novel taxonomy model that includes 150 combined EEG-EOG papers published in peer-reviewed scientific journals and conferences from January 2010 to March 2020. Several data elements were reviewed for each study (e.g., pre-processing, extracted features and performance metrics), which were then examined to uncover trends in aeronautics and summarize interesting methods from this important body of literature. Finally, the review considers the advantages and limitations of these methods as well as future challenges

Integration of motion and cognition within the right cerebellum during motor execution and auditory verbal encouragement: An fMRI study

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Collaboration of Cerebello-Rubral and Cerebello-Striatal Loops in a Motor Preparation Task

International audienceIn this study, we used fMRI to identify brain regions associated with concentration (sustained attention) during a motor preparation task. In comparison with a non-concentration task, increased activities were observed (P < 0.05, FWEcorrected P values) in cerebellar lobules VI and VII, motor cortex, pre-supplementary motor area (pre-SMA), thalamus, red nucleus (RN), and caudate nucleus (CN). Moreover, analysis of effective connectivity inter-areal (psychophysiological interactions) showed that during preparation, concentration-related brain activity increase was dependent on Cerebellothalamo-pre-SMA-RN and Pre-SMA-CN-thalamo-M1 loops. We postulate that, while pre-SMA common to both loops is specifically involved in the movement preparation and readiness for voluntary movement through the striatum, the cerebellar lobule VI in conjunction with RN, likely through a cerebellar-rubro-olivary-cerebellar loop, might be implicated in concentration-related optimization of upcoming motor performances

EOG-Based Human–Computer Interface: 2000–2020 Review

Electro-oculography (EOG)-based brain-computer interface (BCI) is a relevant technology influencing physical medicine, daily life, gaming and even the aeronautics field. EOG-based BCI systems record activity related to users' intention, perception and motor decisions. It converts the bio-physiological signals into commands for external hardware, and it executes the operation expected by the user through the output device. EOG signal is used for identifying and classifying eye movements through active or passive interaction. Both types of interaction have the potential for controlling the output device by performing the user's communication with the environment. In the aeronautical field, investigations of EOG-BCI systems are being explored as a relevant tool to replace the manual command and as a communicative tool dedicated to accelerating the user's intention. This paper reviews the last two decades of EOG-based BCI studies and provides a structured design space with a large set of representative papers. Our purpose is to introduce the existing BCI systems based on EOG signals and to inspire the design of new ones. First, we highlight the basic components of EOG-based BCI studies, including EOG signal acquisition, EOG device particularity, extracted features, translation algorithms, and interaction commands. Second, we provide an overview of EOG-based BCI applications in the real and virtual environment along with the aeronautical application. We conclude with a discussion of the actual limits of EOG devices regarding existing systems. Finally, we provide suggestions to gain insight for future design inquiries

Does the instruction influence voluntary force production regardless of gender during a handgrip exercise ?

International audienceThe aim of this study was to compare the results ofmaximal voluntary contraction (MVC) andmaximal rate of force development (MRFD) in women andmen during handgrip exerciseperformed following three different instructions:Oral instruction (OI):Started with audible trippingandaccompanied by encouragement during the whole muscle contraction. Triggered instruction(TI): Same as oral instruction, but without encouragement. Self-initiated instruction (SI): Thesubject himself decided to start and to stop the contraction.Women’s MVC and MRFD withOIwere higherthan SI. No significant differencehas been found between instructions in men. Ourresults suggested that women are more sensitive to the instructioneffect compared to men. Furtherexplanations will be proposed using surface EMG and fMRI measurements

Cingulate Cortex Atrophy Is Associated With Hearing Loss in Presbycusis With Cochlear Amplifier Dysfunction

Age-related hearing loss is associated with cognitive decline and has been proposed as a risk factor for dementia. However, the mechanisms that relate hearing loss to cognitive decline remain elusive. Here, we propose that the impairment of the cochlear amplifier mechanism is associated with structural brain changes and cognitive impairment. Ninety-six subjects aged over 65 years old (63 female and 33 male) were evaluated using brain magnetic resonance imaging, neuropsychological and audiological assessments, including distortion product otoacoustic emissions as a measure of the cochlear amplifier function. All the analyses were adjusted by age, gender and education. The group with cochlear amplifier dysfunction showed greater brain atrophy in the cingulate cortex and in the parahippocampus. In addition, the atrophy of the cingulate cortex was associated with cognitive impairment in episodic and working memories and in language and visuoconstructive abilities. We conclude that the neural abnormalities observed in presbycusis subjects with cochlear amplifier dysfunction extend beyond core auditory network and are associated with cognitive decline in multiple domains. These results suggest that a cochlear amplifier dysfunction in presbycusis is an important mechanism relating hearing impairments to brain atrophy in the extended network of effortful hearing

EOG-Based Human&ndash;Computer Interface: 2000&ndash;2020 Review

Electro-oculography (EOG)-based brain&ndash;computer interface (BCI) is a relevant technology influencing physical medicine, daily life, gaming and even the aeronautics field. EOG-based BCI systems record activity related to users&rsquo; intention, perception and motor decisions. It converts the bio-physiological signals into commands for external hardware, and it executes the operation expected by the user through the output device. EOG signal is used for identifying and classifying eye movements through active or passive interaction. Both types of interaction have the potential for controlling the output device by performing the user&rsquo;s communication with the environment. In the aeronautical field, investigations of EOG-BCI systems are being explored as a relevant tool to replace the manual command and as a communicative tool dedicated to accelerating the user&rsquo;s intention. This paper reviews the last two decades of EOG-based BCI studies and provides a structured design space with a large set of representative papers. Our purpose is to introduce the existing BCI systems based on EOG signals and to inspire the design of new ones. First, we highlight the basic components of EOG-based BCI studies, including EOG signal acquisition, EOG device particularity, extracted features, translation algorithms, and interaction commands. Second, we provide an overview of EOG-based BCI applications in the real and virtual environment along with the aeronautical application. We conclude with a discussion of the actual limits of EOG devices regarding existing systems. Finally, we provide suggestions to gain insight for future design inquiries

Exploration and analysis of brain-skeletal muscles relationship during motor preparation and execution

Les travaux de cette thèse s’inscrivent à la frontière des neurosciences et de la physiologie musculaire. Trois études se sont articulées de la préparation et l’exécution motrice. La première étude (A) a relié l'activité cérébrale à l'activité musculaire lors de la préparation motrice. Les résultats ont montré que des régions, telles que le cortex moteur primaire et l’aire motrice supplémentaire sont impliquées dans l'activité du muscle fléchisseur (FDS) alors que d’autres régions, telles que les ganglions de la base, les aires fronto-pariétales et le cervelet, sont impliquées dans l'activité du muscle extenseur (EDC). L’étude (B) a exploré le rôle du réseau cérébro-cérébelleux et du réseau striatal lors de l’exécution d’une tâche cognitive et motivationnelle. Les données ont révélé que la partie antérieure du lobule VI droit était activée par l'exécution motrice tandis que sa partie postérieure était spécifiquement activée par les encouragements verbaux. Les mesures de l’interaction psychophysiologique ont permis de faire immerger une boucle de connectivité fermée et formée par le cortex cérébral, le cervelet et les noyaux rouges. La troisième étude (C) concerne l’effet de la consigne réalisée lors de l’exécution motrice sur les paramètres neuromusculaires de FDS et EDC. Les résultats ont montré que la Force Maximale Volontaire, la Pente Maximale de Montée de Force et l’éléctromyographie associée étaient plus élevées (p < 0.05) avec la consigne accompagnée d’encouragement verbal.The present work fits on the border of neurosciences and muscular physiology. Three studies explored the brain and muscle activities following motor preparation and execution. The first study (A) linked brain and muscle activity during motor preparation. The results revealed that regions (e.g primary motor cortex and supplementary motor area) are involved in the activity of the flexor muscle (FDS) while other regions (e.g basal ganglia, fronto-parietal areas and cerebellum) are involved in the activity of the extensor muscle (EDC). The study (B) explored the role of cerebro-cerebellar and striatal networks during the execution period of cognitive and motivational task. The data showed that the anterior part of the right lobule VI was activated by the motor task, while its posterior part was specifically activated by verbal encouragement. Measurements of psychophysiological interaction revealed a closed connectivity loop formed by the cerebral cortex, the cerebellum and the red nuclei. The third study (C) concerned the effect of instruction on neuromuscular parameters of FDS and EDC muscles during motor execution. The results showed that the Maximum Voluntary Force, the Maximum Rate of Force Development and the associated electromyographic signal are the highest (p < 0.05) with cognitive, motivational and verbal encouragement condition