Psychophysiological responses to eye contact with a humanoid robot: Impact of perceived intentionality

Samuli Linnunsalo; Dennis Küster; Santeri Yrttiaho; Mikko J Peltola; Jari K Hietanen

doi:10.1016/j.neuropsychologia.2023.108668

Psychophysiological responses to eye contact with a humanoid robot: Impact of perceived intentionality

Neuropsychologia. 2023 Oct 10:189:108668. doi: 10.1016/j.neuropsychologia.2023.108668. Epub 2023 Aug 22.

Authors

Samuli Linnunsalo¹, Dennis Küster², Santeri Yrttiaho³, Mikko J Peltola⁴, Jari K Hietanen⁵

Affiliations

¹ Human Information Processing Laboratory, Faculty of Social Sciences/Psychology, Tampere University, Tampere, Finland. Electronic address: samuli.pyssysalo@tuni.fi.
² Cognitive Systems Lab, Department of Computer Science, University of Bremen, Bremen, Germany.
³ Human Information Processing Laboratory, Faculty of Social Sciences/Psychology, Tampere University, Tampere, Finland.
⁴ Human Information Processing Laboratory, Faculty of Social Sciences/Psychology, Tampere University, Tampere, Finland; Tampere Institute for Advanced Study, Tampere University, Tampere, Finland.
⁵ Human Information Processing Laboratory, Faculty of Social Sciences/Psychology, Tampere University, Tampere, Finland. Electronic address: jari.hietanen@tuni.fi.

PMID: 37619935
DOI: 10.1016/j.neuropsychologia.2023.108668

Abstract

Eye contact with a social robot has been shown to elicit similar psychophysiological responses to eye contact with another human. However, it is becoming increasingly clear that the attention- and affect-related psychophysiological responses differentiate between direct (toward the observer) and averted gaze mainly when viewing embodied faces that are capable of social interaction, whereas pictorial or pre-recorded stimuli have no such capability. It has been suggested that genuine eye contact, as indicated by the differential psychophysiological responses to direct and averted gaze, requires a feeling of being watched by another mind. Therefore, we measured event-related potentials (N170 and frontal P300) with EEG, facial electromyography, skin conductance, and heart rate deceleration responses to seeing a humanoid robot's direct versus averted gaze, while manipulating the impression of the robot's intentionality. The results showed that the N170 and the facial zygomatic responses were greater to direct than to averted gaze of the robot, and independent of the robot's intentionality, whereas the frontal P300 responses were more positive to direct than to averted gaze only when the robot appeared intentional. The study provides further evidence that the gaze behavior of a social robot elicits attentional and affective responses and adds that the robot's seemingly autonomous social behavior plays an important role in eliciting higher-level socio-cognitive processing.

Keywords: Eye contact; Facial electromyography; Human-robot interaction; N170; P300; Skin conductance.