Delineating the Operational Envelope of Mobile and Conventional EDA Sensing on Key Body Locations

Abstract

Electrodermal activity (EDA) is an important affective indicator, measured conventionally on the fingers with desktop sensing instruments. Recently, a new generation of wearable, battery-powered EDA devices came into being, encouraging the migration of EDA sensing to other body locations. To investigate the implications of such sensor/location shifts in psychophysiological studies we performed a validation experiment. In this experiment we used startle stimuli to instantaneously arouse the sympathetic system of n = 23 subjects while sitting. Startle stimuli are standard but minimal stressors, and thus ideal for determining the sensor and location resolution limit. The experiment revealed that precise measurement of small EDA responses on the fingers and palm is feasible either with conventional or mobile EDA sensors. By contrast, precise measurement of small EDA responses on the sole is challenging, while on the wrist even detection of such responses is problematic for both EDA modalities. Given that affective wristbands have emerged as the dominant form of EDA sensing, researchers should beware of these limitations.

Ambiguity as a Resource to Inform Proto-Practices

“…This fast-changing component is also called skin conductance response, or galvanic skin response. The responses in skin conductance have been studied quite extensively in psychophysiological laboratory studies [48], and it is found that the best placements to observe skin conductance responses (phasic component) are the forehead, palms of hands and soles of feet [83]. In HCI, skin conductance has been used for a variety of purposes, ranging from games [62], self-reflection [42,50], arousal detection for interactive systems [55,85], emotion detection for user studies [45], or arts [74].…”

Towards Affective Chronometry

“…It maps physiologically arousing events to rapid increase and gradual decay of GSR signal. GSR sensors consist of two electrodes worn on the fingers, palm, or wrist [86]. We explored two commercial GSR sensors: BITalino [104], and Grove [105] and chose the latter as it was easier to wear on the wrist [108].…”

A multimodal dataset for various forms of distracted driving

“…Hence, the palm EDA channel appears to be non-informative regarding sympathetic changes produced by either esoteric or physical stressors. In the context of the psychophysiological literature at large, this is surprising, as the palm EDA channel is one of the most reliable peripheral tracker of stress responses 19 . In the context of this application, however, such a disappointing performance is likely attributable to the constant friction of the sensor, as it is squeezed between the subject’s palm and the steering wheel.…”