Combined Head-Mounted Display Virtual Reality and Electroencephalography in the Study of Working Memory

Modern head-mounted display virtual reality (HMD-VR) is used to present immersive virtual environments which reduce external distractions during research. Working memory load (WML) is commonly measured using electroencephalography (EEG), which non-invasively records voltage potential difference responses at the scalp. Having combined HMD-VR and EEG is potentially advantageous for neurophysiological studies of WML as it would allow for the objective measurement of WML in fully controllable and immersive virtual environments. This thesis aimed to investigate the combined use of HMD-VR and EEG in the study of working memory.

A systematic review of WML comparisons between HMD-VR and alternative displays using neurophysiological measures found that the use of HMD-VR has a variable effect on WML relative to screen-based and non-virtual reality presentations. The effect on WML was dependent on HMD-VR configuration and task, but WML predominantly did not differ or was lower in HMD-VR. High-specification HMD-VR and EEG were successfully combined to acquire event related potentials in response to visually and auditorily presented questions in a working memory arithmetic addition task. A follow-up of the arithmetic study compared EEG data preprocessing steps (highpass filtering, lowpass/notch filtering, eye-based artifact removal) to minimise HMD-VR-related artifacts. A spatial navigation study comparing WML between high-specification HMD-VR and desktop-based virtual reality presentations during a learning and recall maze task found that the ratio between theta and alpha frequency band activity did not differ between displays. The main limitation identified is that cybersickness symptoms increased during HMD-VR conditions in the arithmetical and spatial navigation tasks.

Taking the results together, it is found that high-specification HMD-VR was successfully combined with EEG to acquire event related potential and frequency responses. High-specification HMD-VR did not increase WML relative to screen-based virtual reality, indicating its potential utility in research and real-world applications.