This thesis examines the measurement reliability of electrodermal activity (EDA) using a wearable ring compared to a laboratory-grade, wired system. The two central research questions are (i) how well the wearable ring detects phasic responses (SCR) and (ii) how consistently it reflects the tonic level (SCL) relative to the wired system, while accounting for measurement trade-offs (contact impedance, pressure, dynamic range).
Under controlled conditions, N=6 participants (aged 14–24) took part. The devices compared were the Biopac Research Ring (placed on the ring finger of the right hand) and the Biopac MP150 with the GSR100C module (Ag/AgCl electrodes on the index and middle fingers of the right hand). The protocol included a resting baseline and stimuli (scream, click, clap, self-administered pinch) with two-minute intervals. Signals were time-aligned, smoothed with a 1 s moving average, and analysed in 17 s windows; SCL and SCR (threshold > 0.02 µS) were computed, and linear regression between the systems was performed.
The results showed that the wired GSR100C remains more reliable for event-related paradigms (amplitudes, latencies, SCR counting), while the ring is suitable for tracking SCL trends and scenarios where ecological validity is important. Limitations of the study include the small sample size, differences in measurement sites, and environmental conditions. Future research should expand the sample, standardize electrode contact, test in real-world settings, and combine EDA with other physiological indicators (HR, SKT).
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