The objective of the study was to examine how cognitive and perceptual loads affect driving strategies and the guidance of attention. A cue-target search task was implemented and two experiments manipulated prioritizationof a primary task and working memory load (i.e., Experiment 1) and congruence and salience of targets (i.e., Experiment 2). The cues and non-targetdistractors in the environment were designed to influence discriminability and predictability of target locations (e.g., target pedestrians or target squares). Driving related variables along with reaction times and accuracy scores were collected. Lavie et al.s (1) load theory of attention wasused as a framework for the design of the experiments. The authors expected to expand the findings by Lavie et al., (1) to a more realistic drivingenvironment and identify how drivers strategize in conditions of cognitive and perceptual loads. In line with previous studies, both experiments found better lane control during the dual-task period when compared to single-task performance. The other driving results showed detrimental effects of performing secondary tasks while driving. In Experiment 1, prioritization increased target accuracy while decreasing reaction times. In Experiment2, high saliency of targets increased accuracy, but curiously increased reaction times for target detection. Although some results were not as expected, the perceptual load manipulation had an overall negative effect on visual search. In-vehicle interfaces could benefit by incorporating designswhich do not exhaust drivers working memory or distract them with complex displays.
Samenvatting