Thursday, October 21, 2004
Redwood Neuroscience
Title "A neural model of spatial memory,
mental imagery and mental navigation."
Sue
Becker
Professor
of Psychology
Abstract:
In this talk, I will describe a computational model of
the neural mechanisms in the parietal and temporal lobes that support spatial
navigation, imagery, and episodic recall. Long-term allocentric
representations of scenes are stored in the hippocampus and associated with
object and landmark information in the surrounding medial temporal lobe. Viewpoint-dependent representations are
generated in the parietal part of the model to enable construction of an
imagined retinotopic scene and generation of
appropriate body movements.
Bidirectional interactions between the hippocampal
and parietal modules allow translation between allocentric
and egocentric representations, with dynamical interactions between recalled
episodic memories and viewer-centered mental images. Damage to the parietal part of the model
produces symptoms of hemispatial neglect, including
neglect in mental imagery that rotates with the imagined perspective of the
observer as observed in parietally lesioned individuals. Finally, through egomotion-driven
parietal circuits, the model simulates mental navigation.
This is joint work with Neil Burgess at UCL.