Forefront Users' Experience Evaluation by Employing Together Virtual Reality and Electroencephalography: A Case Study on Cognitive Effects of Scents

Abstract

Scents have the ability to affect peoples' mental states and task performance with to different extents. It has been widely demonstrated that the lemon scent, included in most all-purpose cleaners, elicits stimulation and activation, while the lavender scent elicits relaxation and sedative effects. The present study aimed at investigating and fostering a novel approach to evaluate users' experience with respect to scents' effects through the joint employment of Virtual Reality and users' neurophysiological monitoring, in particular Electroencephalography. In particular, this study, involving 42 participants, aimed to compare the effects of lemon and lavender scents on the deployment of cognitive resources during a daily life experience consisting in a train journey carried out in virtual reality. Our findings showed a significant higher request of cognitive resources during the processing of an informative message for subjects exposed to the lavender scent with respect to the lemon exposure. No differences were found between lemon and lavender conditions on the self-reported items of pleasantness and involvement; as this study demonstrated, the employment of the lavender scent preserves the quality of the customer experience to the same extent as the more widely used lemon scent.

Keywords: Electroencephalography (EEG); lavender; lemon; mental effort; neuroscience; scent; smell; virtual reality (VR).

Figure 1

Distribution of participants across the two conditions “lemon” and “lavender”, and the four main phases of the experimental protocol: “VR training and train choice”, “VR neutral environment (baseline)”, “VR train journey” (on train 1 and train 2), and “Questionnaire”.

Figure 2

Electroencephalography (EEG) and Virtual Reality (VR) equipment setup.

Figure 3

VR train journey: each subphase has been rename with the name of the most representative event happening in that specific time interval. The most significant events, for the purposes of the current study, were represented by the “welcome message” (generic message) and the “slowdown message” (informative message).

Figure 4

Interior of the “Frecciarossa” (left side) and “Italo” (right side) high-speed virtual trains.

Figure 5

Brain activity (i.e., EEG signal) recording of one participant during virtual high-speed train trip.

Figure 6

EEG frontal headband with ten electrodes (Fpz, Fp1, Fp2, AFz, AF3, AF4, AF5, AF6, AF7, and AF8).

Figure 7

Mental Effort for the "whole experience" time segment.

Figure 8

Mental Effort for the time segments associated respectively to the generic message (welcome message) and the informative message (slowdown message).

Figure 9

Self-reported measure of “smell awareness” and “smell identification by name”, provided by subjects at the end of the experimental session.

Figure 10

Self-reported measures of pleasantness and involvement associated to the entire virtual reality experience and provided by subjects at the end of the experimental session.

Figure 11

Self-reported measures of "audio involvement", "audio Identification", "audio localization" associated to the entire virtual reality experience and provided by subjects at the end of the experimental session.