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Abstract:
Abstract: The ability to integrate spatial information
acquired at different times is critical for many aspects of spatial
cognition (e.g., integrating different views of a scene). We report
a case of selective disruption to the processes involved in
integrating temporally separated visuo-spatial information. ER is a
teenage girl who suffered prolonged anoxia at birth, resulting in
diffuse brain damage. Although highly verbal, ER suffers from a
range of severe spatial deficits. ER was presented with a visual
letter identification task involving the lower-case print letters
b, d, p, and q. The letters were formed from two features (|,o)
arranged appropriately in a vertical rectangular frame. When the
features were presented simultaneously, ER was able to accurately
identify the letters. However, when the features were presented
sequentially her identification performance was poor. Performance
was unaffected by the interval between the offset of the first
feature and the onset of the second feature (over a range of 100ms
to 3000ms), suggesting that her poor performance was not the result
of memory decay of the features. Furthermore, ER could accurately
draw the sequentially presented features in their proper locations
in a rectangular frame, indicating intact perception and memory of
the features' locations. From this pattern of performance, it is
argued that processes for integrating temporally separated
visuo-spatial information are dissociable from processes involved
in encoding and remembering that information.
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