| |
Abstract:
Abstract: Focal retrograde amnesia (FRA) is a neurological
condition in which patients are drastically impaired as they
attempt to retrieve information that was acquired prior to their
pathology, despite the preserved ability to encode and retrieve new
information. Although FRA is a relatively rare disorder, it has now
been identified and described in more than 20 different case
studies. We summarize these studies, especially with respect to
locus of brain lesion, and the type of information affected. There
were two primary conclusions: (1) In most cases, FRA differentially
affected the retrieval of episodic and semantic memory. A number of
patients were unable to episodically recollect any pre-traumatic
events, yet still knew a number of facts about the world, including
facts about their own lives. Other patients show the inability to
recall learned facts, despite seemingly normal recollection of
personally-experienced events. The double dissociation lends
further support to the distinction between episodic and semantic
memory, and also to the idea that retrieval from the two systems is
independent. (2) Neither the episodic nor semantic form of FRA can
be consistently associated with a lesion in any specific area. FRA
has been discovered following pathology to a wide range of
neocortical structures, although the temporal lobes are usually
implicated.
|
