Body reading
Galvanic skin response and biosensors
GSR / EDA
Measures: Intensity of emotional activation (arousal), not its direction
It shows at which point in the journey the person lit up, and it is good at that: it catches the reaction before it turns into opinion. What it does not distinguish is relief from anger, and the two rise the same on the chart. That is why it almost never appears alone, and goes together with facial analysis or eye tracking, which supply the missing direction.
Wearable biosensors that measure heart rate, breathing rate and, above all, galvanic skin response capture the level of emotional arousal during the interaction. GSR measures variations in the skin’s electrical conductance, which increase with the activation of the sweat glands under the control of the sympathetic nervous system, and it is an indirect but robust measure of emotional engagement, even when the person does not verbalise it or is not aware of it. What it does not do is say whether the emotion is positive or negative; it delivers the intensity, and that is all.
The response splits into a tonic component, slower and more stable, and a phasic one, faster and sensitive to specific stimuli, and it is that granularity that narrows down the moment in the flow when engagement rose. The approximation is coarse, because the response only begins one to four seconds after the stimulus, so it points to a stretch of the journey, not a click. Heartbeat usually comes on the same wristband, and what is read in it is not the average rate but the variability from one beat to the next, which drops under effort and tension. Opening a research topic on neuroscience and emotional design in 2025, QuOrganised the overview of neurophysiological methods applied to emotional design, and concluded that none of them, alone, translates emotion into words.One reference in this work:2025Editorial: neuroscience and emotional designSee in the bibliography → and Duffy go through this entire family, electrical signal, event-related potential, eye movement, oxygenation, heartbeat and facial muscle, and recommend measuring through several channels at once, because none of them, alone, manages to translate emotion into words.
SeesCheap, portable and combinable with EEG, eye tracking and facial analysis.
Does not seeMultifactorial: temperature, hydration and movement also alter conductance.