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Abstract:
Although the putamen has long been regarded as contributing
to the planning and execution of movements, its precise role is
still largely unknown. In primates, electrophysiological studies of
the putamen have shown direction-specific preparatory neuronal
activity, independent of specific features of the movement itself.
Recent research on both animals and humans has found increased
putaminal activity during orientation discrimination. We describe
here a patient with a haemorrhage entirely confined to the right
putamen, who exhibits (1) visual spatial neglect on standard
diagnostic tasks, and (2) a persistent 90 degree counterclockwise
rotation of the vertical axis in a variety of representational
(imagery) tasks. Furthermore, in the nonvisual representational
tasks the rotation of the subjective image seems to eliminate
neglect symptoms and restores the geometric integrity of the
imagined object. This finding suggests a higher cognitive role to
the putamen than has hitherto been demonstrated.
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