Semantic Interference in Mild Alzheimer’s Disease: Preliminary Findings

Objective: The authors evaluated the usefulness and psychometric properties of the Semantic Interference Test (SIT) in patients with mild Alzheimer disease (AD). Methods: Subjects were first presented with 10 common objects to be learned over three trials. Proactive interference was assessed by having subjects recall 10 new objects that were semantically related to the previous ones. Retroactive interference was assessed by having subjects recall the original 10 objects. Results: Controlling for overall memory impairment, very mildly impaired AD patients demonstrated significantly greater proactive and retroactive interference effects than the normal, community-dwelling comparison group. The proactive score alone and the combined proactive-plus-retroactive score index were more effective than traditional neuropsychological measures of delayed recall in distinguishing between the very mildly impaired AD group and the normal-comparison group. Conclusion: The authors discuss the potential usefulness of the SIT in identifying vulnerability to semantic interference in early AD