Severe diffuse traumatic brain injury (TBI) may impair the
performance of daily-life complex activities. The aim of the
present study was to assess whether these difficulties are related
to a representational impairment of action knowledge. Two tasks
requiring the manipulation of scripts were used. The first
(script reconstitution) required subjects to sort cards
describing actions belonging to 4 different scripts, presented
in a random order. The second (script generation) required
subjects to generate actions belonging to a given script. The
results showed that TBI patients had preserved access to goal
representation and action knowledge. However, they demonstrated
(1) significant impairments when they had to deal with simultaneous
competing sources of information and (2) a lack of inhibitory
control on routine overlearned skills. Patients' performance
was significantly correlated with behavioral modifications in
everyday life. These data suggest that action impairment in
severe TBI patients cannot be attributed to an impairment of
action knowledge per se. As previously suggested by
Schwartz et al., a restriction of limited-capacity processing
resources may account for the observed deficits. (JINS,
2001, 7, 795–804.)