Some patients with relatively selective hippocampal damage have shown proportionate recall and recognition deficits. Moreover, familiarity as well as recollection have been found to be impaired in some of these patients. In contrast, other patients with apparently similar damage presented with relatively preserved recognition despite having severely impaired recall, and some of these patients have been shown to have preserved familiarity. We report here the case of an amnesic patient who suffered bilateral hippocampal damage and temporoparietal atrophy after carbon monoxide poisoning. On tests matched for difficulty, his recall performance was more severely impaired than his recognition memory, for verbal as well as for visual materials. Moreover, he performed within the range of healthy matched subjects on nine recognition tests out of ten. In a task using the process dissociation procedure, the patient's familiarity was preserved although his recollection was impaired. These findings indicate that recall and recognition memory can be dissociated in amnesic patients with hippocampal lesions even when temporoparietal cortical atrophy is also present.
Apathy, defined as a reduction in voluntary goal-directed behaviors, is one of the most common behavioral symptoms encountered in Alzheimer disease (AD). However, the processes underlying the different components of apathy are still unclear. The aim of this study was to explore a particularly important aspect of executive function in daily life: multitasking [assessed with the Modified Six Elements Task (MSET)], and its relationship with apathy in AD. Sixty-seven participants (37 AD patients matched with 30 control participants) were screened using the MSET. Simultaneously, a close relative of each patient was given the Apathy Inventory, which assesses 3 distinct dimensions of apathy (lack of initiative, lack of interest, and emotional blunting). AD patients presented significantly more multitasking deficits than control participants. In addition, regression analyses revealed that the number of rule breaks on the MSET (inability to perform several tasks in a predefined time observing a number of rules) was the best predictor of apathy, and especially of lack of initiative. These results suggest that the relation between lack of initiative and multitasking has a specific character and that mechanisms underlying multitasking constitute a key component of goal-directed behaviors.
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