Brain response to a humanoid robot in areas implicated in the perception of human emotional gestures.
BACKGROUND
The humanoid robot WE4-RII was designed to express human emotions in order to improve human-robot interaction. We can read the emotions depicted in its gestures, yet might utilize different neural processes than those used for reading the emotions in human agents.


METHODS
Here, fMRI was used to assess how brain areas activated by the perception of human basic emotions (facial expression of Anger, Joy, Disgust) and silent speech respond to a humanoid robot impersonating the same emotions, while participants were instructed to attend either to the emotion or to the motion depicted.


RESULTS
Increased responses to robot compared to human stimuli in the occipital and posterior temporal cortices suggest additional visual processing when perceiving a mechanical anthropomorphic agent. In contrast, activity in cortical areas endowed with mirror properties, like left Broca's area for the perception of speech, and in the processing of emotions like the left anterior insula for the perception of disgust and the orbitofrontal cortex for the perception of anger, is reduced for robot stimuli, suggesting lesser resonance with the mechanical agent. Finally, instructions to explicitly attend to the emotion significantly increased response to robot, but not human facial expressions in the anterior part of the left inferior frontal gyrus, a neural marker of motor resonance.


CONCLUSIONS
Motor resonance towards a humanoid robot, but not a human, display of facial emotion is increased when attention is directed towards judging emotions.


CONCLUSIONS
Artificial agents can be used to assess how factors like anthropomorphism affect neural response to the perception of human actions.
Chaminade
Thierry
T
Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom. tchamina@gmail.com
Zecca
Massimiliano
M
Blakemore
Sarah-Jayne
SJ
Takanishi
Atsuo
A
Frith
Chris D
CD
Micera
Silvestro
S
Dario
Paolo
P
Rizzolatti
Giacomo
G
Gallese
Vittorio
V
Umiltà
Maria Alessandra
MA
D000328:Adult; D000786:Anger; D001921:Brain / Q000502:physiology*; D004644:Emotions; D005149:Facial Expression; D005260:Female; D005868:Gestures; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012371:Robotics; D055815:Young Adult