After memory impairment, one of the most common troubles of early Alzheimer’s disease (AD) is the impairment of executive functioning. However, it can have major consequences on daily life, notably on the driving activity. The present study focuses on one important executive function involved in driving: mental flexibility; and considered how this impairment can affect driving ability. Other studies, as well as the authors’ previous research, verified that experiments on driving simulators were possible both with older drivers and with AD patients. In the present study, ten patients diagnosed with probable AD were matched with twenty-nine healthy elderly drivers. All participants were given a battery of neuropsychological tests, including an evaluation of mental flexibility. In the driving situation, the participant drove on a virtual road with traffic signs on the right and left sides of the road. He/she had to give the shape of the sign when it was on the right and the main colour of the sign when it was on the left side of the road. The experiment was divided in three conditions, two without mental alternance (all the traffic signs are on the same side), and in the third condition there was alternately a sign on the right and a sign on the left: in this block, the participant had to alternate between right and left, between shape and colour. AD patients showed impairments in the neuropsychological tests evaluating mental flexibility. These deficits are linked to the deficits they showed in the driving simulator. This study also contributed to understanding of mental flexibility mechanisms and on their role in driving activity. It also confirmed that the driving simulator is a suitable environment to explore cognitive disorders and driving ability. (Author/publisher)
Samenvatting