Dysfunctional Default Mode Network during high speed discrimination in the elderly. Neuropsychological and driving simulator correlations.
Numerous daily tasks, including car driving, require fine visuospatial tuning. Onesuch visuospatial ability, speed discrimination, declines with aging but its neuralunderpinnings remain unknown. In this study, we use fMRI to explore the effect ofaging during a high speed discrimination task, along with a completeneuropsychological assessment and a simulated driving evaluation in order toexamine how they interact with each other. Beyond confirming that high speeddiscrimination performance is dimished in the elderly, we found that this deficit mightbe partly due to a lack of modulation in the activity and connectivity of the defaultmode network (DMN) in this age group, as well as an over-recruitment of frontal,basal ganglia and cerebellar regions, possibly as a compensatory mecanism. Thisneural pattern could also be translated to our participants’ cognitive and drivingsimulator performance, such that in young adults, a proper DMN modulationcorrelated with better neuropsychological scores and a driving profile, an effect thatseems to be lost in the elderly. These findings contribute to highlight the role of thedefault mode network on visuospatial tasks, how it is age-related and its impact on cognitive functioning and driving performance in a simulator.