Identifying Relationships between Physiological Measures and Evaluation Metrics for 3D Interaction Techniques

Abstract. This project aims to present a methodology to study the relationships between physiological measures and evaluation metrics for 3D interaction techniques using methods for multivariate data analysis. Physiological responses, such as heart rate and skin conductance, offer objective data about the user stress during interaction. This could be useful, for instance, to evaluate qualitative aspects of interaction techniques without relying on solely subjective data. Moreover, these data could contribute to improve task performance analysis by measuring different responses to 3D interaction techniques. With this in mind, we propose a methodology that defines a testing protocol, a normalization procedure and statistical techniques, considering the use of physiological measures during the evaluation process. A case study comparison between two 3D interaction techniques (ray-casting and HOMER) shows promising results, pointing to heart rate variability, as measured by the NN50 parameter, as a potential index of task performance. Further studies are needed in order to establish guidelines for evaluation processes based on welldefined associations between human behaviors and human actions realized in 3D user interfaces

Haptic Technique for Simulating Multiple Density Materials and Material Removal

The term haptic refers to the tactile sensation perceived by the user when he is manipulating objects in a Virtual Environment. These sensations are extremely important in Virtual Reality simulators for training medical and dental procedures with the goal of increasing the level of motor skills. Many tasks trained, such as teeth and bones drilling, are held in rigid bodies and require parts of the virtual models to be removed. One way to manipulate these objects is by using voxel-based models, which divide the object into smaller parts that can be removed by the haptic device. This paper deals with a new method for haptic rendering with voxel-based rigid bodies that may be composed of various materials with different densities. The method describes the process for obtaining and storing the virtual objects. In addition it details the techniques used for collision detection, calculating the force feedback and removing parts of objects during the drilling process. The paper ends with an experiment that shows that the method provides stability, supports removal of voxels and different material densities properly

Efeitos do treino com jogos de videogame na cognição de idosos: revisão sistemática = Effects of video game training on cognition in the elderly: systematic review

Objetivos: realizar uma revisão sistemática da literatura sobre o efeito do treino com jogos de videogame na cognição de idosos. Métodos: Busca nas bases de dados LILACS, SciELO, PsycINFO e PubMed, idiomas Inglês e Português. Utilizaram-se os descritores treino com jogos de videogame / video game training, adicionando aos seguintes: cognição / cognition, efeito cognitivo / cognitive effects, desempenho cognitivo / cognitive performance, plasticidade cognitiva / cognitive plasticity, testes cognitivos / cognitive tests. Foram incluídos estudos de intervenção cognitiva, artigos originais e disponíveis na íntegra, população alvo idosos (60 anos ou mais), publicados entre 2005 e 2015. A revisão ocorreu entre janeiro e julho de 2015. Resultados: Dos 70 artigos encontrados inicialmente, 21 estudos atenderam aos critérios de seleção. Sete estudos (33%) verificaram melhoras significativas em velocidade de processamento, atenção sustentada, alerta, memória de trabalho visoespacial, flexibilidade cognitiva, memória visual imediata e tardia e coordenação viso-motora-espacial. Em relação à metodologia de treino dos estudos, 11 (52%) foram com treino de curta duração (uma a seis semanas) e tempo total entre menor tempo 4,5 horas e maior tempo 23,5 horas; e 10 (47%) com treino de longa duração (sete a 12 semanas) e tempo total de treino entre 12 e 36 horas. Os treinos de curta duração foram mais eficazes Conclusões: A constatação do tempo total necessário de treino foi o achado principal desta revisão sistemática. Intervenção cognitiva com uso de jogos de vídeo game de curta duração, entre uma e seis semanas, e tempo total do programa de treino cognitivo entre 4,5 horas e 23,5 horas foi eficaz para idosos, sendo esta uma dose de tempo de intervenção cognitiva necessária e suficiente para a consolidação de sistemas e aquisição de um aprendizado no envelhecimento. Os efeitos cognitivos encontrados nos estudos sugerem que o cérebro idoso é capaz de adquirir, manter e enriquecer-se com novas aprendizagen

Conventional Mirror Therapy versus Immersive Virtual Reality Mirror Therapy: The Perceived Usability after Stroke

Background. Stroke is a widespread and complex health issue, with many survivors requiring long-term rehabilitation due to upper-limb impairment. This study is aimed at comparing the perceived usability of two feedback-based stroke therapies: conventional mirror therapy (MT) and immersive virtual reality mirror therapy (VR). Methods. The study involved 45 participants, divided into three groups: the stroke survivors (n=15), stroke-free older adults (n=15), and young controls (n=15). Participants performed two tasks using both MT and VR in a semirandom sequence. Usability instruments (SUS and NASA-TLX) were applied at the end of the activities, along with two experience-related questions. Results. The results indicated that both MT and VR had similar levels of perceived usability, with MT being more adaptable and causing less overall discomfort. Conversely, VR increased the perception of task difficulty and prevented participants from diverting their attention from the mirror-based feedback. Conclusion. While VR was found to be less comfortable than MT, both systems exhibited similar perceived usability. The comfort levels of the goggles may play a crucial role in determining the usability of VR for upper limb rehabilitation after stroke