Assessment of Age Differences in Mental Workload whileDriving using Verbal versus Visual-Spatial Subsidiary Tasks

摘要

Age differences in mental workload demands imposed by driving were investigated using a dual-taskparadigm. Two subsidiary tasks, thought to tax separate attentional resource pools (verbal versus visualspatial),were compared. Dual-task cost ratios [Rtdual-task/Rtsingle-task] using each subsidiary task werecollected from young (mean age = 20.6) and older (mean age = 72.4) drivers at midblock locations (lowdriving task load) and while approaching intersections (high driving task load). Consistent withexpectations, age differences were exacerbated on the visual-spatial subsidiary task. However, theexpected workload increase at intersections (relative to midblock locations) was not observed. Instead, amore complex 3-way interaction of roadway location with subsidiary task and task order was obtained.This pattern of results has important implications with regard to the following two issues: 1) the use ofdiscrete versus continuous subsidiary task probes during real world driving, and 2) the sensitivity andspecificity of subsidiary task approaches in the assessment of age-related cognitive deficits and theirpotential impact upon driving performance.