title: Emotional Responses in Virtual Reality Environments
Creators: name: Baker, C
Publisher: name: Liverpool John Moores University
Year: 2021

description: The use of virtual reality (VR) technology to induce emotional responses has recently become more common in psychological studies. The majority of these studies have been restricted to seated VR experiences where the participant remains in a sedentary position. The purpose of the current thesis is to utilise room-scale VR to increase presence, agency and potency of virtual environments (VE) designed to induce embodied emotional responses. The Evaluative Space Model (ESM) [Cacciopio et. al 2012] was used as the theoretical basis for this programme of research, which was particularly concerned with avoidance responses to negative stimuli, perception of threat and negativity bias. A number of unique VEs were created using Unreal Engine 4 designed to create an illusion of height and the potential for a virtual fall as a source of threat. These VEs were supplemented by additional tracking sensors and an integrated approach to data collection wherein behavioural interactions and movements within the VE were synchronised with ambulatory methods from psychophysiology, e.g. facial electromyography (fEMG), skin conductance level (SCL). The first study (N=20) utilised a VE that requires participants to walk on a wooden plank between the rooftops of two buildings, two versions of the VE were created: sedentary version operated via gamepad controller and a room scale version with natural sensorimotor mappings. The study revealed greater psychophysiological reactivity for the room-scale version of the environment. The second study (N=34) introduced an elaborated room-scale VE where participants must traverse a grid of translucent ice blocks suspended at height in order to reach an end-goal within a physical space of 9m2. This grid contained three types of ice block: solid (low-threat), crack (mid-threat) or fall (high threat). The number of crack and fall blocks were increased over three levels of the VE in order to manipulate threat. The foot movements of participants were tracked as the primary mode of interaction with the VE. The study revealed: (i) higher incidence of risk-averse behaviours as threat increased, (ii) this pattern of behaviour was enhanced for participants with higher levels of trait neuroticism, and (iii) greater reactivity from the corrugator muscle in the period following a two-feet movement. The third study (N=20) represented an extension of study two where a significantly larger version of the ice block VE was created in a physical space of 27m2. In this experiment, the level of threat (i.e. number of crack and fall blocks) was increased, sustained and decreased in order to study adaptation to reduced threat level. In addition, a ‘ground level’ version of the VE was utilised as a control to study the effect of virtual height in isolation. The results of this study revealed: (i) participants adjusted behaviour to increased threat and decreased threat, but only in the presence of virtual height, and (ii) increased activation of zygomaticus during interactions with crack blocks, which suggests this muscle may be associated with a ‘grimace’ response in this context. The final experimental chapter represents a re-analyses of the data from studies 2 and 3 designed to explore individual differences as predictors of risk averse behaviour in response to the threat. These analyses identified trait neuroticism and age as traits that significantly influenced the magnitude of the negativity gradient in response to threat. The implications of the research for studying emotional experiences in VR are discussed.