Abstract
In the US, 1,506 people were treated in emergency room for an injury caused due to using cell while walking, in 2010 (Nasar, 2013). The underlying mechanisms for interference of locomotion by a secondary task is not well understood. Studies suggest "in-attentional blindness" contributes (Hyman 2010; 2015) but have not addressed walking biomechanics. Biomechanically, people walk more "cautiously" while using cell phones (Lambert, 2012; Cha, 2015; Haga, 2015) but collisions are not studied. Additionally, walking is affected by attention and executive function (Seligmann, 2008). This study investigated the effects of performing a secondary task (on cell phone) on the ability to avoid obstacles while walking, and the impact of executive function on performance. Thirty young adults walked on a treadmill and negotiated virtual obstacles by shifting laterally, while playing a game on a cell phone. Cognitive capacity was quantified, using PEBL Perceptual Vigilance Task and Berg's Card Sorting Test. The cell phone task led to a 6.45% increase in the time taken to avoid obstacles (Movement Time), and 44.11% increase in the variation in Movement Time (Standard Deviation of Movement Time). There was a significant increase in the number of collisions due to cell phone use. Individuals with higher Reaction Time and Failure to Maintain Set had higher Percent Collisions; individuals with higher cognitive flexibility performed better on the cell phone task. There was a significant but weak correlation between baseline cognitive measures and performance on the secondary and the locomotion task, only when both the tasks were performed simultaneously. Performing a secondary task during locomotion causes an increase in collision, delay in response and increase in the variability of response to obstacles. Moreover, ability to avoid obstacle and perform the secondary task while walking depends on executive function.
Meeting abstract presented at VSS 2017