Sympathetic Nervous System response following video observation of balance loss during walking - explorative study

Background: Video observation of one's own loss of balance may evoke emotional and physiological arousal, yet little is known about how such stimuli affect sympathetic nervous system (SNS) activity as measured by Electrodermal activity (EDA). Research question: This study investigated whether observing video recordings of one's own balance loss during treadmill walking induces a measurable EDA response? and whether such responses habituate over repeated exposures? Methods: Thirty-four healthy young adults were presented with six video clips showing their own balance losses during treadmill walking. EDA was continuously monitored using finger electrodes. Skin conductance response (SCR) was quantified as the difference between pre- and post-observation SCLs and normalized using a relative SCR/SCL (%) index. Results: All participants exhibited significant phasic EDA responses (SCRs) following each observed perturbation (P<=0.05), with the strongest response during the first viewing (0.38+-0.41 uS) and a progressive decline across subsequent trials (0.10+-0.18 uS by trial six). Linear regression revealed a significant attenuation in absolute SCR values (R2=0.80, p=0.016), indicating rapid physiological habituation. Relative SCL deltas (SCR/SCL%) followed a similar trend (R2=0.58, p =0.079), further supported by a mixed-effects model showing a significant decline in log-transformed relative SCR values. Significance: These findings demonstrate that video-based self-observation of balance loss reliably elicits sympathetic activation that rapidly habituates with repetition. The steep habituation trajectory suggests rapid cognitive appraisal and reclassification of the visual threat as non-threatening. This approach may serve as an objective, low-burden proxy for assessing fall-related concern and emotional reactivity, with potential applications in clinical screening, therapeutic desensitization, and fall-prevention programs.