  With the advancements in social robotics and virtual avatars, it becomes
increasingly important that these agents adapt their behavior to the mood,
feelings and personality of their users. One such aspect of the user is
empathy. Whereas many studies measure empathy through offline measures that are
collected after empathic stimulation (e.g. post-hoc questionnaires), the
current study aimed to measure empathy online, using brain activity collected
during the experience. Participants watched an affective 360 video of a child
experiencing domestic violence in a virtual reality headset while their EEG
signals were recorded. Results showed a significant attenuation of alpha, theta
and delta asymmetry in the frontal and central areas of the brain. Moreover, a
significant relationship between participants' empathy scores and their frontal
alpha asymmetry at baseline was found. These results demonstrate specific brain
activity alterations when participants are exposed to an affective virtual
reality environment, with the level of empathy as a personality trait being
visible in brain activity during a baseline measurement. These findings suggest
the potential of EEG measurements for development of passive brain-computer
interfaces that assess the user's affective responses in real-time and
consequently adapt the behavior of socially intelligent agents for a
personalized interaction.
