Effects of semantic relations, repetition of words, and list length in word list recall of Alzheimer's patients.

INTRODUCTION: Semantic relations among words and repetition enhance free recall, but it is unknown if these facilitating factors are effective in dementia.

METHOD: Alzheimer's patients (MILD-Alz, MOD-Alz) were compared to healthy elderly. Fifteen-word lists were read out to the subjects. In four sets of lists the words in intermediary input positions were semantically related or not, or the midlist words were repeated, or they were repeated and semantically related.

RESULTS: The usual third peak of recall of semantically related words was not observed in MOD-Alz, repetition of words did not increase recall of the patients, and the combination of relatedness and repetition benefited only MID-Alz. In a second experiment, with related or unrelated midlist words, and list length shortened from 15 to 9 words, semantic facilitation was observed in mild and moderate Alzheimer s patients, although diminished compared to controls.

CONCLUSION: Progression of dementia turns facilitating factors of recall less effective.