Proxemics of screen mediation: engagement with reading on screen manifests as diminished variation due to self-control, rather than diminished mean distance from screen

Objective: Burgoon's theory of conversational involvement suggest that when people engage with a person, they will move slightly closer to them, often subtly and subconsciously. However, some studies have failed to extend this to human-computer interaction. Our hypothesis is that during online reading, engagement is associated with an expenditure of effort to hold the head upright, still and centrally. Method: We presented to 27 participants (ages 21.00 ± 2.89, 15 female) seated in front of 47.5x27 cm monitor two reading stimuli in a counterbalanced order, one (interesting) based on a best selling novel and the other (boring) based on European Union banking regulations. The participants were video-recorded during their reading while they wore reflective motion tracking markers. The markers were video-tracked off-line using Kinovea 0.8. Results: Subjective VAS ratings showed that the stimuli elicited the bored and interested states as expected. Video tracking showed that the boring stimulus (compared to the interesting reading) elicited a greater head-to-screen velocity, a greater head-to-screen distance range, a greater head-to-screen distance standard deviation, but not a further away head-to-screen mean distance. Conclusions: The more interesting reading led to efforts to control the head to a more central viewing position while suppressing head fidgeting.