Authors:

SIMONS, J.S., Verfaellie, M., GRAHAM, K.S., Galton, C.J., PATTERSON, K., & HODGES, J.R.

Reference:

Year of publication:

2001

CBU number:

5024

Abstract:

It has been convincingly demonstrated that patients with semantic dementia (the temporal variant of frontotemporal dementia) can show intact recognition memory for pictorial stimuli. As yet, the contribution made by recollective processes to this ability, and the status of associated neural regions, have not been investigated in the disease. Here, we used both a source monitoring paradigm and an associative memory test to evaluate the ability of patients with semantic dementia to utilise recollection-based memory processes, and a volumetric MRI technique to assess the extent of atrophy in medial temporal lobe regions. Although some patients showed impaired recollection-based memory, others performed as well as control participants. There was no positive correlation between recollection and volume of the hippocampus; instead, both source discrimination and associative memory correlated highly with performance on a battery of frontal lobe tests. Consistent with the view that damage to prefrontal cortex might influence recollection performance, patients with the frontal variant of frontotemporal dementia, with atrophy largely confined to the frontal lobes, all performed at floor levels on source discrimination. These results are interpreted in the light of current theories about the cognitive and neural organisation of long-term memory systems.