Off-campus WSU users: To download campus access dissertations, please use the following link to log into our proxy server with your WSU access ID and password, then click the "Off-campus Download" button below.

Non-WSU users: Please talk to your librarian about requesting this dissertation through interlibrary loan.

Access Type

WSU Access

Date of Award

January 2011

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Psychology

First Advisor

Lisa J. Rapport

Abstract

This study examined the relationship of neuropsychological and on-road driving evaluations among adults with acquired brain injury (ABI), and the extent to which that relationship is moderated by awareness of deficit. Awareness of deficit may partly explain mixed findings regarding the relationship between cognitive function and driving outcomes, inasmuch as persons aware of their deficits attempt to compensate for them accordingly, thereby minimizing deficit-related risk.

Sixty-two pairs of adults with ABI and significant-other informants recruited from a driving evaluation center and 40 healthy controls participated. Adults with ABI and controls completed neuropsychological and on-road evaluations.

Awareness of deficit was directly related to driving outcomes and was also a moderator between the relationship of neuropsychological functioning and driving performance. Multiple regression indicated the interaction between neuropsychological test performance and awareness of deficits explained significant variance in driving performance. The moderation effect was illustrated by different relationships between neuropsychological and on-road performances among the awareness groups: Among adults with impaired awareness (n = 21), neuropsychological functioning was substantially related to driving outcomes; in contrast, driving outcome showed weak relation to neuropsychological functioning among those with intact (n = 24) or hypervigilance (n = 17) toward their deficits. An exception was that processing speed showed modest relation to on-road outcome for all groups, including healthy controls. Adults with impaired awareness of their deficits rated their driving more highly than did adults with hypervigilance towards or intact awareness of their deficits. Significant-other ratings were strongly related to use of driving limitations among survivors with impaired awareness of their deficits, consistent with findings that the caregivers "hold the keys."

Awareness of deficit has a considerable influence on driving outcomes both directly and as a moderator between the relationship of neuropsychological functioning and driving performance. When adults with ABI lack appreciation for their impairments, their neuropsychological status is especially important in predicting driving outcomes. Even minor deficits, if not recognized and compensated for appropriately, can increase driving risk substantially.