Abstract
Patients with Alzheimer's disease (AD) often produce false recall or intrusion errors in memory tests. We conducted two experiments to investigate three types of responses (correct recall, false recall, and non-recall) in 59 AD patients who participated in verbal paired association tasks (PAL), and whether the presence of false recall was related to memory (experiment one) or other neurocognitive functions such as attention and executive control (experiment two).
The Spearman's correlation analysis was conducted in the first experiment, and it was found that false recall produced in PAL tasks did not correlate with poor performance on memory test such as WMS-R and ADAS. In experiment two, we investigated the relationship between the tendency for false recall and both attention and executive functions. We selected the poor PAL learners, i. e. those whose correct recall rate was less than 75%, and divided them into three groups : false recall (FR) group who exhibited false recall in more than 75% of the responses ; non-recall (NR) group, who exhibited non-recall in more than 75% of the responses ; and mixed (MIX) group, in which both types of errors were present. Performance of three groups on attention and category fluency (CF) tasks was then compared. Results of the Jonckheere-Terpstra test indicated that the more the subjects' false recall increased, the worse their performance on the attention and CF tasks. From these results, we concluded that false recall in AD patients is related to inattention, ineffective use of semantic knowledge, and executive dysfunction.
