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Abstract:
Abstract: While some investigators have found that retrograde
amnesia in patients with medial temporal lobe damage is temporally
graded, with relative sparing of remote memories (Squire and
Alvarez, 1995), others contend that impairment is of very long
duration and that remote memories are not necessarily spared (Nadel
and Moscovitch, 1997). In this study, remote memory was assessed in
26 patients with unilateral Temporal Lobe Epilepsy and 22
non-neurologically impaired controls using the Autobiographical
Memory Interview (AMI) (Kopelman, 1989) and a famous faces test.
Results for the AMI indicate that patients have impaired personal
episodic memory but intact personal semantic memory. The impairment
in episodic memory extends to the most remote time periods in
childhood, long before seizure onset in many patients. Only
patients with right temporal damage were impaired on the famous
faces test and only for the most recent decade. Our results
indicate that medial temporal damage or dysfunction, due to
recurrent seizures or surgical excision, can result in extensive
retrograde amnesia for personal episodic memories, limited
retrograde amnesia for public figures, and little amnesia for
personal semantic memories. These findings support a memory loss or
retrieval deficit account of retrograde amnesia, in which
differential vulnerability of memories is a function of the number
of traces coding the experience, rather than the time needed to
consolidate the traces.
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