Speed of information processing in traumatic brain injury: modality-specific factors.
OBJECTIVE
To assess speed of information processing by two serial addition tests (one visual, one auditory) in individuals with moderate-to-severe traumatic brain injuries (TBIs) and in a healthy, normal control group (NC). The tasks were designed to equate and control for accuracy of performance across the TBI and NC groups, thus allowing for quantification of information processing speed.


METHODS
Performance across groups and tasks were compared using 2 x 2 repeated measure analyses of variance (ANOVAs). In addition, each individual's processing speed was used to adjust rate of stimulus presentation on a subsequent "rehabilitation" trial to determine further whether this adjustment equated accuracy of performance.


METHODS
Rehabilitation hospital.


METHODS
22 outpatients with moderate-to-severe TBI (6 women, 16 men; mean age = 34.6 years; duration of loss of consciousness = 22.6 days) and 20 age- and education-matched healthy controls.


RESULTS
Processing speed was slower in TBI subjects, relative to controls and was significantly related to measures of executive functioning for those with TBI. Relative to controls, speed of processing in the TBI group was disproportionately slower when information was presented in the auditory, relative to the visual, modality.


CONCLUSIONS
Speed of information processing is a major impairment in those with TBI when unconfounded by performance accuracy. The modality-specific impairment observed in the TBI group may, in part, be due to a greater within-modality interference effect created by the auditory version of the task. By manipulating information at a pace customized for an individual through compensatory strategies and environmental modifications, information-processing performance of TBI participants can be enhanced significantly.
Madigan
N K
NK
Department of Psychology, Massachusetts Mental Health Center, Boston, Massachusetts, USA.
DeLuca
J
J
Diamond
B J
BJ
Tramontano
G
G
Averill
A
A
D000328:Adult; D000704:Analysis of Variance; D001307:Auditory Perception; D001930:Brain Injuries / Q000523:psychology*; D016022:Case-Control Studies; D003071:Cognition; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010045:Outpatients; D011930:Reaction Time; D014796:Visual Perception