Abstract: Objective To investigate the changes of the semantic priming effect in patients with brain injury.Methods Eight patients with Alzheimer's disease(AD),fifteen patients with vascular dementia(VD),seventeen patients with traumatic brain injury (TBI),twenty four healthy young subjects,and seventeen elderly healthy subjects as normal controls were estimated by Mini-Mental State Examination(MMSE),clinical memory scale,and process dissociation procedure(PDP) tasks.The data of all subjects were analyzed.Results The patients in the AD group had lower recollection and automatic scores than those in the young and elderly control groups in free association task(P<0.05～0.001).The recollection scores in the VD and TBI groups decreased significantly when compared with that in the young and elderly control groups in free association tasks(P<0.001),whereas the automatic scores had no significant difference among four groups(P>0.05).Conclusion AD patients exhibited impaired explicit memory and semantic priming effect,but retain normal perceptual priming effect;VD and TBI patients showed impaired explicit memory,but retained normal semantic priming effect.

Key words: semantic priming effect, explicit memory, Alzheimer's disease, vascular dementia, traumatic brain injury