Implicit and explicit memory outcome in children who have sustained severe traumatic brain injury: Impact of age at injury (preliminary findings)

Primary objective: To examine implicit and explicit memory outcome in children who had sustained severe traumatic brain injury (TBI) through childhood. Opposite patterns of impairments were expected: (i) impaired implicit memory in children with early TBI (TBI-EC,<6 years) and (ii) impaired explicit memory in children with late TBI (TBI-LC,≥6 years). Research design: Children who had sustained severe TBI more then 1 year ago were assessed. Methods and procedure: Fourteen children who had sustained severe TBI (TBI-EC, n=10 and TBI-LC, n=4) between 8 months and 13 years 7 months of age and 13 non-injured control subjects (NC) participated. Implicit (repetition priming and skill learning) and explicit verbal memory were examined. Results: The TBI group performed worse on implicit (repetition priming) and explicit memory tasks compared to the NC group. Moreover, impairments were found in implicit and explicit memory in the TBI-EC, but not in the TBI-LC group. Conclusions: This study has shown, for the first time, that severe childhood TBI may compromise not only explicit, but also implicit memory. Nevertheless, instead of a selective implicit memory impairment, it was found that children who sustained injuries in early childhood present with impairments in both memory systems.