Hazard prediction and risky decision-making by drivers affected by non-hemineglect strokes

Abstract

The stroke survivor’s independence is severely limited if they are prevented from driving, and regaining this ability could be vital to their recovery. Our pioneering study analysed hazard prediction and risky decision-making among drivers who had suffered non-hemineglect strokes. Two groups of experienced drivers were recruited with one group comprising 37 healthy drivers (M = 54.5 years old, SD = 6.59) and the other consisting of 37 drivers who had had non-hemineglect strokes (M = 55.1 years old, SD = 13.7). In terms of lesion location, 59 % (n = 22) had suffered a left-hemisphere injury, 35 % (n = 13) a right-hemisphere injury, and 5 % (n = 2) a bilateral injury. Hemineglect patients were excluded. Participants were shown naturalistic driving video clips which had been recorded from the driver’s point of view. These were filmed both in the participants’ familiar home country (Spain) and also in an unfamiliar country (England). The hazard prediction test showed a number of hazardous situations which were caused by another road user (e.g. an oncoming car invading the lane). Each video clip ended as the hazard began to unfold, and participants had to choose the correct response to identify the hazard, where it occurred, and the likely outcome in that particular traffic situation (situation awareness). In the risky decision-making test, participants were shown video clips whereby the hazards were possibly caused by risky driving behaviour (e.g. driving through a junction with an amber traffic light). The participants were also shown video clips which set up the potential for risky behaviour and they were asked how likely they were to proceed with that risky manoeuvre (e.g. to overtake a cyclist or drive through a junction with an amber traffic light) on a 6-point Likert scale. In the hazard prediction test, a statistically significant group effect was found, with healthy drivers attaining greater accuracy compared to drivers who had suffered a stroke. More specifically, drivers with left-sided strokes had lower hazard prediction accuracy (M = 59.1 %, SD = 16.7) than drivers with right-sided strokes (M = 64.6 %, SD = 11.8) and healthy drivers, who had the highest accuracy percentage (M = 68.6 %, SD = 13.1). Moreover, a significant effect was found regarding familiarity, and driver accuracy in the hazard perception test was found to be greater in the video clips filmed in Spain than those filmed in England. However, the interaction between these factors was not significant. Regarding the risky decision-making test, the only statistically significant effect was with the familiarity of the video clips, whereby drivers displayed a greater disposition to assume risks in the English video clips (unfamiliar driving environment) than in the Spanish clips. Hazard prediction training would be particularly helpful for drivers who had suffered left-hemisphere strokes since it is more difficult for such drivers to process details.