Abstract
Talking on a cell phone can impair driving performance (e.g., Stayer & Drews, 2007), but the specifics of when common attentional resources are needed are not fully understood. We examined the effects of varying the visual attention load of the driving task by manipulating familiarity with the driving environment (broad visual environment) and presence of attention demanding driving elements (specific visual targets). To vary familiarity with the driving environment, participants completed six runs through the same driving environment in a driving simulator. To vary attention to specific driving elements, there were two crosswalks with pedestrians on the side of or in the road. Half of the participants left voicemail messages on a new topic on each run (e.g., Talk about the classes your taking this semester, Talk about your favorite TV show or recent book you read) using a hands-free headset, while the other half drove in silence. In order to determine the effects of the visual attention demanding events on driving for participants who left voicemails versus those that did not, we measured velocity and steering deviation across four critical sections (45-30, 30-15, and, 15-0 meters before the crosswalks, and 0-15 meters after the crosswalks) of the last four driving runs. Leaving a voicemail increased steering deviation and velocity. However, the size of these effects decreased for the later runs, and was largest close to the crosswalks. This suggests that as more attention is needed in the visual environment, because the environment is less familiar and/or there are critical visual targets to attend to (pedestrians), leaving a voicemail leads to more erratic driving behavior (faster and more steering deviation). These results demonstrate that leaving a voicemail requires attentional resources that are also needed both for attending to the broad driving environment and for attending to specific visual targets.
Meeting abstract presented at VSS 2017