Exploring the effect of action familiarity on SPTs recall performance in Alzheimer's disease

This study examined the performance of normal controls (NC) and Alzheimer's disease (AD) patients on free recall, semantic cued recall and object cued recall of both subject-performed tasks (SPTs) and verbal descriptions of actions, by controlling familiarity of actions associated to objects. The results showed that both groups performed better after SPT encoding than after verbal encoding, in all three types of recall. In addition, this SPT advantage was greater for AD patients than for NC in the object cued recall test, emphasizing AD patients' sensibility to the congruence of cues between encoding and retrieval conditions. Following verbal encoding, NC showed a better recall for less familiar actions than for highly familiar actions, whereas AD patients exhibited the opposite pattern. These results reflect that AD patients did not benefit from a distinctiveness effect at encoding for improving subsequent retrieval of verbal information, probably due to a reduced level of elaboration during encoding. However, there was no effect of action familiarity on recall performance by both groups following SPT encoding. These results suggest that memory for verbal actions and SPTs is governed by different principles. In addition, they demonstrate the robustness of the SPT effect in AD patients, who were able to improve memory performance in the SPT condition not only with highly familiar actions but also with less familiar actions.