The aim of the present study was to assess the functioning of the
different subsystems of working memory after severe traumatic brain injury
(TBI). A total of 30 patients with severe chronic TBI and 28 controls
received a comprehensive assessment of working memory addressing the
phonological loop (forward and backward digit span; word length and
phonological similarity effects), the visuospatial sketchpad (forward and
backward visual spans), and the central executive (tasks requiring
simultaneous storage and processing of information, dual-task processing,
working memory updating). Results showed that there were only marginal
group differences regarding the functioning of the two slave systems,
whereas patients with severe TBI performed significantly poorer than
controls on most central executive tasks, particularly on those requiring
a high level of controlled processing. These results suggest that severe
TBI is associated with an impairment of executive aspects of working
memory. The anatomic substrate of this impairment remains to be
elucidated. It might be related to a defective activation of a distributed
network, including the dorsolateral prefrontal cortex. (JINS,
2007, 13, 770–780.)