Detection of imminent collisions by drivers with Alzheimer's disease and Parkinson's disease: a preliminary study

Abstract

The aim of this study was to assess whether patients with neurodegenerative disease, namely Alzheimer's disease (AD) and Parkinson's disease (PD), differed from age-matched, neurologically normal comparison participants in their ability to detect impending collisions. Six AD patients and 8 PD patients, together comprising the neurodegenerative disease group, and 18 comparison participants completed a collision detection simulation task where they must judge whether approaching objects would collide with them or pass by them. The neurodegenerative disease group was less sensitive in detecting collisions than the comparison group, and sensitivity worsened with increasing number of objects in the display and increasing time to contact of those objects. Poor performance on tests of cognition and visual attention were associated with poor collision detection sensitivity. The results of this study indicate that neurodegenerative disease impairs the ability to accurately detect impending collisions and that these decrements are likely the combined result of visual and cognitive disturbances related to disease status.

Figure 1

Static image of the driving scene used in the experiment.

Figure 2

Schematic illustration of the aerial display geometry for collision events. All objects were positioned at a constant radial distance from the observer at the beginning of the trial (Figure 2A). During the trial the objects moved toward the viewpoint of the observer, each on its own linear path (Figure 2B). For collision trials one of the objects approached on a linear path that would eventually collide with the observer. The number of objects in the scene was either a single object or 6 objects.

Figure 3

Mean sensitivity (d’) as a function of TTC, number of objects, and observer group.