The current paper reviews and discusses digital game design for elderly users. The aim of the paper is to look beyond the traditional perspective of usability requirements imposed by age-related functional limitations, towards the design opportunities that exist to create digital games that will offer engaging content combined with an interface that seniors can easily and pleasurably use.

The concept of presence, i.e. the sensation of 'being there' in a mediated environment, has received substantial attention from the virtual reality community, and is becoming increasingly relevant both to broadcasters and display developers. Although research into presence is still at an early stage of development, there is a consensus that presence has multiple determinants. To identify and test which parameters affect presence, a reliable, robust and valid means of measuring presence is required. In this paper, we describe the categories of factors thought to have an impact on presence. Furthermore, we present an overview of various approaches taken to measuring presence, which can be divided into two general categories: subjective measures and objective corroborative measures. Since presence is a subjective experience, the most direct way of assessment is through users' subjective report. This approach has serious limitations however, and should be used judiciously. Objective measures, such as postural, physiological or social responses to media, can be used to corroborate subjective measures, thereby overcoming some of their limitations. At present, the most promising direction for presence measurement is to develop and use an aggregate measure of presence that is comprised of both subjective and objective components, tailored to the specific medium under study.

This paper presents a first study in which a recently reported intermodal perceptual illusion known as the rubber hand illusion is experimentally investigated under mediated conditions. When one's own hand is placed out of view and a visible fake hand is repeatedly stroked and tapped in synchrony with the unseen hand, subjects report a strong sense in which the fake hand is experienced as part of their own body. In our experiment, we investigated this illusion under three conditions: (i) unmediated condition, replicating the original paradigm, (ii) virtual reality (VR) condition, where both the fake hand and its stimulation were projected on the table in front of the participant, and (iii) mixed reality (MR) condition, where the fake hand was projected, but its stimulation was unmediated. Dependent measures included self-report (open-ended and questionnaire-based) and drift, that is, the offset between the felt position of the hidden hand and its actual position. As expected, the unmediated condition produced the strongest illusion, as indicated both by self-report and drift towards the rubber hand. The VR condition produced a more convincing subjective illusion than the MR condition, although no difference in drift was found between the mediated conditions. Results are discussed in terms of perceptual mechanisms underlying the rubber hand illusion, and the illusion's relevance to understanding telepresence.