Changes in brain structures of younger and older drivers: Meeting the challenge

Ian Glendon, Griffith University, Australia

Of demographic groups, younger and older drivers are particularly studied, with research typically focusing upon behavioural, cognitive and affective influences upon driving.  This chapter explores neurological structures of younger and older brains to consider what aspects of changing brain physiology are particularly likely to impact critical driving tasks.

For example, changes in the balance between brain structures associated with executive function and emotional expression mean that behaviours of younger drivers are particularly likely to be driven by reward seeking, novelty seeking, sensation seeking, risk taking and ‘reckless’ behaviours.  In teenagers and emerging adults, integrating emotions and cognitions occurs over an extended period, which could expose younger drivers to danger resulting from an underdeveloped ability to handle stress.  The corpus callosum, linking the left and right brain hemispheres, does not stabilise until early adulthood, meaning that younger drivers with ‘mixed handedness’ could be particularly at risk from hazards involving complex tasks requiring both hands and more than one sense modality.  Areas of the brain responsible for creating mental imagery are still developing in younger adults, so that processing critical information about generically dangerous situations can take longer.

Neurological changes associated with normal aging are inevitable for those with sufficient longevity.  A robust finding for cognitive aging in older adults is that of significant episodic memory decline, resulting from reductions in semantic memory and episodic retrieval.  Possible implications for driving could include delays in retrieving stored information about previous traffic encounters that might be critical to an immediate event.  Deficits in context processing and use may underlie some cognitive aging phenomena.  Within a driving context, this might be associated with confusion and errors resulting from unfamiliar surroundings or from stimuli overload.  White matter changes in the older brain are associated with declining mental processing speed, which could impact decision-making ability in driving situations, some of which might be critical.  Dissociations between attentional processes in anterior and posterior attentional networks within the brain result in greater liability for distraction from irrelevant novel sounds, which could adversely impact older drivers’ ability to select relevant stimuli quickly enough from a range of those presented.

As a result of brain physiology that is changing more quickly than that of individuals in their mid-years, both younger and older drivers experience distinctive issues in their respective driving environments.  The chapter addresses factors that can mitigate some potentially damaging outcomes that could result from these changes, as well as recommending ways in which some driving tasks might be modified to enhance the performance of these driver groups.