  This paper presents an experiment to assess the feasibility of using
secondary input data as a method of determining user engagement in immersive
virtual reality (VR). The work investigates whether secondary data (biosignals)
acquired from users are useful as a method of detecting levels of
concentration, stress, relaxation etc. in immersive environments, and if they
could be used to create an affective feedback loop in immersive VR
environments, including educational contexts. A VR Experience was developed in
the Unity game engine, with three different levels, each designed to expose the
user in one of three different states (relaxation, concentration, stress).
While in the VR Experience users physiological responses were measured using
ECG and EEG sensors. After the experience users completed questionnaires to
establish their perceived state during the levels, and to established the
usability of the system. Next a comparison between the reported levels of
emotion and the measured signals is presented, which show a strong
correspondence between the two measures indicating that biosignals are a useful
indicator of emotional state while in VR. Finally we make some recommendations
on the practicalities of using biosensors, and design considerations for their
incorporation in to a VR system, with particular focus on their integration in
to task-based training and educational virtual environments.
