Designing a gesture-sound wearable system to motivate physical activity by altering body perception

People, through their bodily actions, engage in sensorimotor loops that connect them to the world and to their own bodies. People's brains integrate the incoming sensory information to form mental representations of their body appearance and capabilities. Technology provides exceptional opportunities to tweak sensorimotor loops and provide people with different experiences of their bodies. We recently showed that real-time sound feedback on one's movement (sonic avatar) can be used for sensory alteration of people's body perception, and in turn provoke enhanced motor behaviour, confidence and motivation for physical activity (PA) in people while increasing their positive emotions towards their own bodies. Here we describe the design process of a wearable prototype that aims to investigate how we can overcome known body-perception-related psychological barriers to PA by employing action-sound loops. The prototype consists of sensors that capture people's bodily actions and a gesture-sound palette that allows different action-sound mappings. Grounded in neuroscientific, clinical and sports psychology studies on body perception and PA, the ultimate design aim is to enhance PA in inactive populations by provoking changes on their bodily experience

From presence to consciousness through virtual reality

Immersive virtual environments can break the deep, everyday connection between where our senses tell us we are and where we are actually located and whom we are with. The concept of 'presence' refers to the phenomenon of behaving and feeling as if we are in the virtual world created by computer displays. In this article, we argue that presence is worthy of study by neuroscientists, and that it might aid the study of perception and consciousness

Biochemical characterization and low-resolution SAXS shape of a novel GH11 exo-1,4-β-xylanase identified in a microbial consortium

Biotechnologies that aim to produce renewable fuels, chemicals, and bioproducts from residual ligno(hemi)cellulosic biomass mostly rely on enzymatic depolymerization of plant cell walls (PCW). This process requires an arsenal of diverse enzymes, including xylanases, which synergistically act on the hemicellulose, reducing the long and complex xylan chains to oligomers and simple sugars. Thus, xylanases play a crucial role in PCW depolymerization. Until recently, the largest xylanase family, glycoside hydrolase family 11 (GH11) has been exclusively represented by endo-catalytic β-1,4- and β-1,3-xylanases. Analysis of a metatranscriptome library from a microbial lignocellulose community resulted in the identification of an unusual exo-acting GH11 β-1,4-xylanase (MetXyn11). Detailed characterization has been performed on recombinant MetXyn11 including determination of its low-resolution small angle Xray scattering (SAXS) molecular envelope in solution. Our results reveal that MetXyn11 is a monomeric globular enzyme that liberates xylobiose from heteroxylans as the only product. MetXyn11 has an optimal activity in a pH range from 6 to 9 and an optimal temperature of 50 oC. The enzyme maintained above 65% of its original activity in the pH range 5 to 6 after being incubated for 72 h at 50 oC. Addition of the enzyme to a commercial enzymatic cocktail (CelicCtec3) promoted a significant increase of enzymatic hydrolysis yields of hydrothermally pretreated sugarcane bagasse (16% after 24 h of hydrolysis)

Auditory Presence, Individualized Head-Related Transfer Functions, and Illusory Ego-Motion in Virtual Environments

It is likely that experiences of presence and self-motion elicited by binaurally simulated and reproduced rotating sound fields can be degraded by the artifacts caused by the use of generic Head-Related Transfer Functions (HRTFs). In this paper, an HRTF measurement system which allows for fast data collection is discussed. Furthermore, effects of generic vs. individualized HRTFs were investigated in an experiment. Results show a significant increase in presence ratings of individualized binaural stimuli compared to responses to stimuli processed with generic HRTFs. Additionally, differences in intensity and convincingness of illusory self-rotation ratings were found for sub-groups of subjects, formed on the basis of subjects localization performance with the given HRTFs catalogues

Travelling without moving: Auditory scene cues for translational self-motion

Creating a sense of illusory self-motion is crucial for many Virtual Reality applications and the auditory modality is an essential, but often neglected, component for such stimulations. In this paper, perceptual optimization of auditory-induced, translational self-motion (vection) simulation is studied using binaurally synthesized and reproduced sound fields. The results suggest that auditory scene consistency and ecologically validity makes a minimum set of acoustic cues sufficient for eliciting auditory-induced vection. Specifically, it was found that a focused attention task and sound objects’ motion characteristics (approaching or receding) play an important role in self-motion perception. In addition, stronger sensations for auditory induced self-translation than for previously investigated self-rotation also suggest a strong ecological validity bias, as translation is the most common movement direction

Wahrnehmung von Eigenbewegung in Virtual Reality - kognitive und multi-sensorische Aspekte

Zur Untersuchung der Eigenbewegungsillusion (Vektion) wurden klassischerweise abstrakte visuelle Stimuli (z.B. Streifenmuster) verwendet. Wir untersuchten mit Hilfe von Virtual Reality kognitive und multi-sensorische Effekte der Eigenbewegungswahrnehmung - diese Aspekte fanden bisher kaum Berücksichtigung. In einer Serie von Vektionsexperimenten fanden wir folgende Ergebnisse: Eine photorealistische Szene eines Raumes verstärkt die Vektion, verglichen zu abstrakten visuellen Stimuli, die keine räumliche Interpretation zulassen. In vier multi-sensorischen Vektionsexperimenten (auditiv-somatosensorisch, visuell-somatosensorisch, visuell-auditiv, visuell-vestibulär) fanden wir jeweils eine Verstärkung der Vektion durch multi-sensorische Stimulation. Hierbei scheint es einen moderierenden kognitiven Effekt zu geben: So erzeugten z.B. Geräusche von statischen Geräuschquellen (Brunnen) mehr Vektion als solche, die sich in der Umwelt bewegen (Schritte). Generell trat die multi-sensorische Verstärkung nur in solchen Fällen auf, in denen eine ökologisch valide Übereinstimmung zwischen den Stimuli vorlag. Somit scheint bei der multi-sensorischen Eigenbewegungswahrnehmung eine kognitive Bewertung den Integrationsprozess der Sinnesinformation zu beeinflussen - dies wurde in bisherigen Erklärungsmodellen nicht berücksichtigt