Measuring users' emotional responses in multisensory virtual reality: a systematic literature review.

Virtual reality and emotions have become inseparable concepts over the past few years, supported by the increasing number of studies relating them. However, these studies' methodologies are often poorly justified or dependent on the authors' subjective definition of emotion and its classification. Moreover, frequently, these studies only consider two stimuli, specifically audiovisual, despite being known the relevance of including a greater variety of sensory channels to improve the relationship between the individual and the virtual environment. So, to address these gaps, and considering the importance of multisensory stimulation, this paper aims to review the methods and instruments found in the literature regarding the analysis of the users' emotions in virtual reality. Also, we provide an overview of the main limitations of such studies. Little information can be found in the literature regarding the connection between the input stimulus and the users' emotional responses. This corroborates the difficulty in creating and evaluating immersive virtual experiences when stimulating more than two human senses, typically audiovisual. Nevertheless, we address some clues on the impact of visual, auditory, haptic, smell, and taste elements to trigger specific emotions. Also, we address the association between the research area and the method used. Finally, the main gaps and challenges are discussed. We expect that the combination of these results acts as guidelines for designing richer multisensory virtual experiences. Moreover, we intend to contribute to future research on emotions-based immersive virtual reality by providing a review of the most suitable methodologies and instruments for specific contexts. [ABSTRACT FROM AUTHOR]