Recall and Recognition in Alzheimer's Disease and Frontotemporal Dementia

Background: It has long been debated whether performance on recall and recognition tests depends on the same or different
memory systems and whether performance on these two tasks is dissociated in clinical populations. According to Dual
process theories of recall, performance on recall and recognition tests dissociates in the relative reliance on frontal lobe
related activities; in fact, the recall test requires more strategic retrieval of memoranda than the recognition task. By contrast,
Dual process theories of recognition posit that performance on these tests differs in the relative contribution of recollection
and familiarity memory processes in the two tasks: both recollection and familiarity contribute to recognition judgments, but
only recollection supports recall performance.
Objective: The aim of this study was to clarify the cognitive processes involved in recall and recognition in patients with
dementia.
Methods:We administered a 15-word recall task followed by a yes/no recognition paradigm to 28 patients with Alzheimer’s
disease (AD), 22 patients with the behavioral variant of frontotemporal dementia (bvFTD), and 45 normal controls (NCs).
Results: Results showed that on the delayed recall task, bvFTD patients performed much better than AD patients but the two
groups did not differ on any index of recognition performance.
Conclusion: The present data support the hypothesis that the performance of the two groups is expression of the different
reliance on recollection (more impaired in the AD than in the bvFTD group) and familiarity (similarly impaired in the two
groups) in performance on recall and recognition tasks.