A brief summary of current research.
Measuring processing speed after traumatic brain injury in the outpatient clinic
Fong, K, Chan, M, Ng, P and Ng, S. NeuroRehabilitation, Volume 24 (2), pp 165-73.
When compared with non-injured people, individuals with brain injury were substantially slower on measures of reaction time, movement time, and mental processing speed. However, while people with TBI were slower, their accuracy did not differ significantly from their non-injured peers.