Research Reports - Visuospatial attention after traumatic brain injury
Brain Inj. 2015 Oct 9:1-13. [Epub ahead of print]
Hill-Jarrett TG(1), Gravano JT(1), Sozda CN(2), Perlstein WM(1,)(3).
PRIMARY OBJECTIVE: To evaluate the behavioural and neural effects of TBI on the
hemispheric integrity of three components of visuospatial attention: alerting,
orienting and executive control.
METHOD: Behavioural performance and high density event-related potentials (ERPs)
were acquired while a sample of 12 patients with chronic moderate-to-severe TBI
and 12 controls performed the Lateralized Attention Network Test (LANT). Neural
indices of attention (posterior N1 amplitude to alerting and orienting cues,
midline P3 amplitude during conflict resolution) were examined.
RESULTS: Patients with TBI exhibited smaller N1 amplitude to alerting cues, but
comparable behavioural performance to controls. Participants with TBI also
demonstrated poorer orienting performance to the left hemispace relative to the
right. A corresponding reduction in right hemisphere N1 was found during left
orienting to spatial cues in the TBI group. No group differences were observed on
behavioural measures of executive control; however, patients with TBI exhibited
reduced P3 amplitude overall.
CONCLUSIONS: TBI may have an enduring effect on the orienting system at both
neural and behavioural levels. Assessment of attention in chronic TBI can be
improved by the integration of hemispheric findings that suggest disproportionate
vulnerability in leftward orienting. Results may enhance clinical sensitivity to
detection of subtle signs of neglect.