Aging Brains Degrade Driving Safety Performances of the Healthy Elderly

Abstract

The relationship between aging brains and driving safety performances (DSPs) of elderly drivers was studied. A total of 90 dementia-free participants (63 men and 27 women, mean age 75.31 ± 4.795 years) were recruited and their DSPs were analyzed on actual vehicles running through a closed-circuit course. DSPs were comprehensively evaluated on the basis of driving instructors' scores (DIS). Signaling and visual research behaviors, part of DSPs, were measured to supplement the DIS evaluation by driving recorders (DR) and wearable wireless sensors (WS), respectively. Aging brains were evaluated via magnetic resonance imaging (MRI) findings and experimentally assigned to two grades (high vs. low) of brain atrophy (BA) and leukoaraiosis (LA). Regression analyses on DIS and DR data, and logistic analysis on WS scores showed significant correlations of aging brains with degradation of DSPs. The participant group with more advanced BAs and LAs showed lower DIS, DR data, and WS scores representing degraded DSP regardless of age. These results suggest that MRI examinations from both volumetric and pathological perspectives of brains have the potential to help identify elderly drivers with dangerous driving behaviors. Brain healthcare, lifestyle improvements and medical treatments to suppress BA and LA, may contribute to preventing DSP degradation of elderly drivers with aging brains.

Parietal and occipital leukoaraiosis due to cerebral ischaemic lesions decrease the driving safety performance of healthy older adults

“…We calculated DSP scores at six locations on the closed-circuit track as previously described [23] . Reduced DSP scores when turning right at an intersection were only associated with parietal and occipital LA.…”

“…1a). In this test, six locations on the driving course were selected for rating DSPs as previously described [23] . The tasks included changing lanes while driving straight (P1 in Fig.…”

“…The participant then drove with the evaluating instructor sitting in the passenger seat. The instructor rated the driving skills of each participant using a previously described method [23,32] . DSP scores at the six locations P1-P6 were then calculated by assessing some of the six categories depending on the location: 'searching (safety recognition and behaviour with head movement)', 'speeding (choice of vehicle speed)', 'signaling (the timely and appropriate usage of the indicator)', 'stability (acceleration and braking without knocking and completely pulling up in front of the stop line)', 'positioning (vehicle movement along the curvature radius at intersections without large or small turns)', and 'steering (smooth handling with appropriate starting and ending)'.…”

“…The authors reported that healthy older drivers with higher LA grades produced more driving-related errors, such as ignoring stop signs, failing to con rm a safe right-of-way by checking both sides at intersections, and steering disturbances, compared to those without LA. In another driving test conducted on a closed-circuit course without distracting tasks, LA grades were statistically correlated with lower DSP scores when brain atrophy (BA) and LA grades were used as explanatory variables [23] . This indicates that BA may have a similar effect to distractors when LA affects DSP.…”

“…In all studies so far, however, LA was qualitatively classi ed based on MRI imaging by medical specialists; LA volume and localisation have never been evaluated in relation to DSP assessment [21][22][23] . A method to automatically measure LA volumes was recently developed [24] and has been used to elucidate in detail the correlations with various DSP tasks like changing lanes while driving straight, driving along a large curve with poor visibility, turning right and left at intersections, and stopping at a sign.…”