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Abstract:
Deficits in spatial memory have been demonstrated in patients
suffering from Korsakoff amnesia. According to Mayes' contextual
memory hypothesis (1992), this is a result of problems in the
processing of contextual information-such as spatial information -
in these patients. However, spatial context memory, i.e. memory for
object locations, is not a unitary concept, but can be divided into
at least three sub-mechanisms (Postma & De Haan, 1996, 1998, in
press). First, there is encoding of the exact positions (regardless
of object information). Second, object information has to be linked
to its spatial location, i.e. binding of item and location
information. Third, there might be a mechanism for the integration
of metric encoding and object-position binding. In the present
study, this subdivision of spatial context memory was studied in a
group of Korsakoff patients (n = 20) to see whether selective
impairments could be found. Spatial layouts containing everyday
objects were presented using a computer task (Kessels et al., in
press). Measures of non-spatial (object) memory and visuo-spatial
ability were used as control variables. The results showed
impairments and delay effects on all spatial-memory conditions, as
well as on object memory and visuo-construction compared to matched
controls (n = 20). Apparently, a general deficit in spatial memory,
including both positional encoding and object-location binding,
exists in Korsakoff patients, possibly due to fronto-diencephalic
degeneration (cf. Chalfonte et al., 1996).
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