Ultra-late EEG potential evoked by preferential activation of unmyelinated tactile afferents in human hairy skin

International audienceHuman tactile sensibility in hairy skin is mediated not only by fast conducting myelinated (A) afferents, but also by a system of slow conducting, unmyelinated afferents that respond preferentially to light touch, C-tactile (CT) afferents. This system has previously been shown to correlate with the pleasantness of tactile stimuli, where a soft brush moving at 1–3 cm/s activates CT afferents strongly. Functional magnetic resonance imaging (fMRI) studies have shown that preferential CT fiber stimulation activates the posterior insula cortex. The present study aims to assess brain activity evoked by the activation of CT afferents using electroencephalography (EEG). We present evidence for a late cortical potential over frontal electrodes, evoked from slow, gentle brush strokes at 3 cm/s. We relate this to the CT afferent input based on the conduction velocity of the CT fibers and the force feedback from the brush; the potential started 0.7 s after the brush contacted the skin and continued throughout the brush stimulation. Furthermore, results from brushing at lower and higher speeds showed that the CT potential was modulated by this stimulation. We conclude that the late potential is consistent with activity in a frontal cortical network following hairy skin peripheral stimulation. This provides an important tool for further studies of the CT fiber system and for clinical examination of peripheral unmyelinated afferents

Investigating the Putative Impact of Odors Purported to Have Beneficial Effects on Sleep: Neural and Perceptual Processes

International audienceIntroduction Olfaction has an important role in physiological and affective processes, as well as the potential to have profound effects on activities such as sleep and learning. We investigated two commercially manufactured odors ("Deep Sleep" and "Oriental," from This Works) purported to promote sleep, compared with control odor, where we aimed to explore whether neural and behavioral differences existed after odor inhalation. Methods In a neuroimaging study, 30 healthy participants were exposed to the odors via an olfactometer during functional magnetic resonance imaging (fMRI). In a further behavioral study using 12 chronic insomniacs, we investigated whether the commercial odors showed effects on sleep during a double-blind, randomized home evaluation. Results In the neuroimaging, the odors were related to activation of olfactory-relevant areas, such as the orbitofrontal cortex, and we found positive connectivity between the piriform cortex and the hippocampus, amygdala, insula, and middle cingulate cortex. Deep Sleep specifically activated the superior temporal gyrus, whereas Oriental activated the caudate. Further, these commercial odors showed some beneficial impact on sleep. Conclusions The perceptual and neural impacts of the commercial odors showed that olfactory stimulation can potentially aid sleep and modify affective processes in a number of ways. Implications The present work opens up opportunities for further investigations into how different odors may lead to specific behavioral and physiological modifications, such as their impact on sleep and well-being, which may provide non-pharmacological alternative approaches

Insights and Perspectives on Sensory-Motor Integration and Rehabilitation

The present review focuses on the flow and interaction of somatosensory-motor signals in the central and peripheral nervous system. Specifically, where incoming sensory signals from the periphery are processed and interpreted to initiate behaviors, and how ongoing behaviors produce sensory consequences encoded and used to fine-tune subsequent actions. We describe the structure-function relations of this loop, how these relations can be modeled and aspects of somatosensory-motor rehabilitation. The work reviewed here shows that it is imperative to understand the fundamental mechanisms of the somatosensory-motor system to restore accurate motor abilities and appropriate somatosensory feedback. Knowledge of the salient neural mechanisms of sensory-motor integration has begun to generate innovative approaches to improve rehabilitation training following neurological impairments such as stroke. The present work supports the integration of basic science principles of sensory-motor integration into rehabilitation procedures to create new solutions for sensory-motor disorders

Case Studies in Neuroscience: Sensations elicited and discrimination ability from nerve cuff stimulation in an amputee over time

International audienceThe present case study details sensations elicited by electrical stimulation of peripheral nerve axons using an implanted nerve cuff electrode, in a participant with a transhumeral amputation. The participant uses an osseointegrated electromechanical interface, which enables skeletal attachment of the prosthesis and long-term, stable, bidirectional communication between the implanted electrodes and prosthetic arm. We focused on evoking somatosensory percepts, where we tracked and quantified the evolution of perceived sensations in the missing hand, which were evoked from electrical stimulation of the nerve, for over 2 yr. These sensations included small, pointlike areas of either vibration or pushing, to larger sensations over wider areas, indicating the recruitment of a few and many afferents, respectively. Furthermore, we used a two-alternative forced choice paradigm to measure the level of discrimination between trains of brief electrical stimuli, to gauge what the participant could reliably distinguish between. At best, the participant was able to distinguish a 0.5-Hz difference and on average acquired a 3.8-Hz just-noticeable difference at a more stringent psychophysical level. The current work shows the feasibility for long-term sensory feedback in prostheses, via electrical axonal stimulation, where small and relatively stable percepts were felt that may be used to deliver graded sensory feedback. This opens up opportunities for signaling feedback during movements (e.g., for precision grip), but also for conveying more complex cutaneous sensations, such as texture

Evolution of the emotional maturity in basic proffesional formation students throught the use of out of school activities

Las aulas de la nueva modalidad de FP Básica, se caracterizan por presentar una alta concentración de alumnos con significativas carencias en su madurez emocional y en su alfabetización científica. El siguiente artículo analiza la evolución de la madurez emocional de 16 alumnos del primer curso de FP Básica de la rama de Peluquería, utilizando las actividades fuera del contexto escolar como recurso educativo para la asignatura de Ciencias de la Naturaleza. Estas actividades, están diseñadas de forma que se incida tanto en el aspecto cognitivo, como en el emocional, incluyendo tareas individuales o en equipo y siempre conectando su conocimiento cotidiano con el escolar. Tras la realización de las actividades, los alumnos son entrevistados de cara a analizar una serie de indicadores emocionales predeterminados. Estos indicadores, responden a los antónimos establecidos por Díaz y Flores (2001) y que constituyen la denominada Plantilla General de Indicadores Emocionales. Las respuestas de los alumnos son analizadas utilizando una Plantilla Específica de Diferenciales Semánticos, definida a tal efecto, según tres momentos diferentes en los que se manifiesta la emoción: durante la actividad, en el aula y fuera ya del centro. El tratamiento de los datos obtenidos permite comparar la evolución de la madurez emocional en el transcurso de las actividades, observándose una evolución emocional importante entre los estados inicial y final, de manera general, en alumnos de esta tipología.The new implementations of the FP Básica (Spanish equivalent of a Foundation Degree) tend to gather quite a high number of students in the same classroom. In general, these students lack emotional and scientific literacy. The following investigation analyses the evolution of the emotional literacy of 16 students in their first year of FP Básica in the hairdressing sector, using some out of the scholar context interdisciplinary activities as an educative resource. Once the activities have taken place, the students are interviewed in order to analyse a series of predetermined emotional indicators which constitute to the denominated General Stencil of Emotional Indicators and respond to the antonym of the ones established by Díaz y Flores (2001). The answers of the students are analysed using Specific Templates of Semantic Pairs, according to three different situations where the emotions happen: during the activity, in the classroom and finally outside the school. The processing of the different results allows us to compare the evolution of the emotional literacy in the course of the tasks. Taking into account the starting and final statuses, an important emotional evolution is noticed generally among the students

PENGEMBANGAN JOBSHEET TRAINER PLC SEBAGAI SUMBER PEMBELAJARAN PRAKTIKUM OTOMASI INDUSTRI

Penelitian ini bertujuan untuk mengembangkan sebuah media pembelajaran sebagai sumber belajar mahasiswa berupa jobsheet praktikum Otomasi Industri. Selain itu, penelitian ini bertujuan untuk mengetahui kelayakan dari jobsheet yang telah dikembangkan serta melihat hasil implementasi jobsheet setelah digunakan oleh para mahasiswa. Penelitian ini dirasa perlu dilakukan untuk membuat sebuah sumber belajar yang layak serta dapat memberikan manfaat lebih khususnya mahasiswa Elektronika Indsutri. Metodologi yang digunakan oleh penulis pada penelitian ini menggunakan penelitian campuran dengan model rancangan campuran sekuensial eksploratori, menggunakan pendekatan penelitian dan pengembangan (Research and Development). Berdasarkan hasil penelitian yang telah dilakukan didapatkan hasil bahwa jobsheet trainer PLC Phoenix Contact ILC 130/131 Starterkit telah dikembangkan sesuai tahapan penelitian dan layak digunakan serta dapat diimplementasikan dalam praktikum Otomasi Industri.---This study aims to develop learning media as a source of students learning in form of practical Industrial Automation jobsheet. Besides, this study aims to prove the feasibility of jobsheet that has been developed and the result of jobsheet implementation by students. This study is considered important to create a decent learning resource and provide benefits, especially for Electronics Industries Students, Department of Electrical Engineering Education, Faculty of Technology and Vocational Skills Education. The methodology used by the authors in this study is mixed research model with exploratory sequences, using a research and development approach (research and development). Based on study results, trainer jobsheet of PLC Phoenix Contact ILC 130/131 Starterkit feasible to be used and can be implemented in practice Industrial Automation

Differential effects of radiant and mechanically applied thermal stimuli on human C-tactile afferent firing patterns

International audienceC-tactile (CT) afferents respond to gentle tactile stimulation, but only a handful of studies in humans and animals have investigated whether their firing is modified by temperature. We describe the effects of radiant thermal stimuli, and of stationary and very slowly moving mechanothermal stimuli, on CT afferent responses. We find that CT afferents are primarily mechanoreceptors, as they fired little during radiant thermal stimuli, but they exhibited different patterns of firing during combined mechano-cool stimulation compared with warming. CTs fired optimally to gentle, very slowly moving, or stationary mechanothermal stimuli delivered at neutral temperature (~32°C, normal skin temperature), but they responded with fewer spikes (median 67% decrease) and at significantly lower rates (47% decrease) during warm (~42°C) tactile stimuli. During cool tactile stimuli (~18°C), their mean instantaneous firing frequency significantly decreased by 35%, but they often fired a barrage of afterdischarge spikes at a low frequency (~5 Hz) that outlasted the mechanical stimulus. These effects were observed under a variety of stimulus conditions, including during stationary and slowly moving touch (0.1 cm/s), and we complemented these tactile approaches using a combined electrical-thermal stimulation experiment where we found a suppression of spiking during warming. Overall, CT afferents are exquisitely sensitive to tactile events, and we show that their firing is modulated with touch temperatures above and below neutral skin temperature. Warm touch consistently decreased their propensity to fire, whereas cool touch produced lower firing rates but afterdischarge spiking

Investigating the Effect of Tactile Input and Output Locations for Drivers’ Hands on In-Car Tasks Performance

This paper reports a study investigating the effects of tactile input and output from the steering wheel and the centre console on non-driving task performance. While driving, participants were asked to perform list selection tasks using tactile switches and to experience tactile feedback on either the non-dominant, dominant or both hands as they were browsing the list. Our results show the average duration for selecting an item is 30% shorter when interacting with the steering wheel. They also show a 20% increase in performance when tactile feedback is provided. Our findings reveal that input prevails over output location when designing interaction for drivers. However, tactile feedback on the steering wheel is beneficial when provided at the same location as the input or to both hands. The results will help designers understand the trade-offs of using different interaction locations in the car