Two mechanisms have been shown to influence attentional control: endogenous (top-down) and exogenous (bottom-up) control. This study examines these mechanisms. Posner's cue-target paradigm was modified to study how endogenous and exogenous cues interact with cognitive load to influence drivers' attention in a complex dynamic situation. In a driving simulator, pedestrian crossing signs that predicted the spatial location of pedestrians acted as endogenous cues. To impose cognitive load on drivers, the participants performed an auditory task that simulated the demands of emerging in-vehicle technology. Irrelevant exogenous cues were added to half of the experimental drives by including scene clutter. Results showed that the validity of endogenous cues influenced how drivers scanned for pedestrian targets. Cognitive load delayed drivers' responses, and scene clutter reduced drivers' fixation durations to pedestrians. Cognitive load diminished the influence of exogenous cues to attract attention to irrelevant areas, and drivers were more affected by scene clutter when the endogenous cues were invalid. The findings indicate that cognitive load suppresses interference from irrelevant exogenous cues and delays endogenous orienting of attention in driving. The findings also indicate that the modified Posner's paradigm provides a useful foundation for connecting theoretical construct to an applied, practical task.
Samenvatting