Neuropsychological assessment of executive functions in traumatic brain injury: hot and cold components

This study aims to compare the decision making process between patients with traumatic brain injury (TBI) and healthy controls. In addition, it also aims to identify dissociations and the frequency of deficits in executive functions (EF) tasks, that mainly assess decision making (DM – hot component) and inhibition (cold component), following TBI. The sample was comprised of 16 post-TBI adults aged between 18 and 68 years and of 16 healthy controls, matched by age and education. They were assessed by means of Iowa Gambling Task (IGT) for DM evaluation, Trail Making Task (TMT) and Hayling Test for inhibitory control assessment. There were no differences between groups regarding the performance on IGT, total and block scores. However, TBI patients preferred the disadvantageous decks, without learning evidence along the task. Seven patients showed a dissociation between deficitary DM on IGT versus accurate inhibition on Hayling Test and on TMT. Conversely, five patients presented a partial dissociation with deficit on IGT and on TMT, with an opposite performance in Hayling Test. Only three cases had deficits in all instruments. In this way, after a TBI a patient can keep a comparable performance on IGT. Moreover, as dissociations among hot and cold executive components were found, when they are associated they can aggravate each other.