Electrodermal Responses During Tactile Interaction: Estimating Stress Levels with a Handheld Social Robot

Pocket-sized and ubiquitous robots have potential as accessible tools for affective regulation, but adaptive behavior requires sensing the user's state during interaction. This paper investigates whether galvanic skin response (GSR) electrodes integrated directly into a handheld tactile robot can detect short-term changes in arousal while the device is actively held, pressed, and squeezed, creating a challenging context for acquiring biofeedback signals. We conducted an A--B--A within-participant experiment with 22 participants, comparing two calm rhythm-following conditions with a two-minute stress/arousal condition. Relative GSR peak amplitude did not significantly distinguish the stress/arousal condition from either baseline. In contrast, GSR peak rate was significantly higher during the stress/arousal condition than during both A1 (p=.030), and A2, (p=.003). These results suggest that embedded GSR can potentially provide useful event-level arousal information in a noisy handheld interaction context, particularly when interpreted through the frequency and temporal development of phasic responses rather than the amplitude of individual peaks.