Effects of acceleration, frequency and mild motion sickness on continuous tracking task accuracy in response to simulated wind-induced building motion

This study investigates the effects of acceleration, frequency and motion sickness on task performance. Using a mixed factorial design, we exposed 40 participants to a range of sinusoidal accelerations (8 to 30 milli-g), frequencies (0.125 to 1 Hz) and motion directions (fore-aft and lateral) in a purpose-built motion simulator. In each experimental condition, participants undertook a 64-second continuous tracking task by directing a laser pointer at the centre of a target. We measured motion sickness and sopite syndrome pre- and post-exposure to motion. Task performance accuracy decreases with increases in acceleration. Accuracy also decreases with increases in frequency from 0.125 Hz to 0.5 Hz. Frequency and acceleration interact, with accuracy being lowest at 30 milli-g and 0.5 Hz. Participants affected by sopite syndrome (mild motion sickness) show significantly lower accuracy than relatively unaffected participants. Acceleration caused the largest performance reduction (d = 1.81), followed by sopite syndrome (d = 1.11), then frequency (d = 0.93). We propose that these effects are caused by the interaction of acceleration near 0.5 Hz because it interferes with the resonance frequency of the standing human. Participants appear unable to maintain baseline performance in these motion conditions. The implications for building motion serviceability criteria are discussed.