Conclusion
We set out to test pupillometry as an objective indicator of touch
processing. In a first experiment, we showed that the pupil responded
differently following tactile stimulation at the finger, arm, and calf.
More specifically, the pupil responded more strongly following
stimulation of more sensitive body locations. In a second experiment, we
found that the pupil responded more strongly to vibrotactile stimulation
of higher intensities applied at the finger. Altogether, these findings
show that pupil responses have the potential to be used as an objective
index of tactile sensitivity that is not dependent on verbal responses.