Rotational remapping in human spatial memory during eye and head motion.
The brain uses vision and other senses to compute the locations of objects relative to the body, and then must update these locations when the body moves. How geometrically sophisticated is this internal updating? It has been suggested that updating simply shifts the stored locations of all objects uniformly, by a common vector, when the eye or head turns. For horizontal and vertical turns, a uniform shift would often approximate the real changes in location of objects in front of the subject. But for torsional rotations, a shift would be inadequate: accurate updating would call for a more geometrically exact remapping, not shifting but rotating the stored locations through the inverse of the rotation of the eye in space. Here we asked human subjects to make eye saccades to remembered targets after torsional head rotations. Their accuracy showed that spatial updating works in the torsional dimension and operates by rotation rather than shifting.
Medendorp
W Pieter
WP
Canadian Institutes of Health Research Group for Action and Perception, York University, Toronto, Ontario, Canada M3J 1P3. pieter@yorku.ca
Smith
Michael A
MA
Tweed
Douglas B
DB
Crawford
J Douglas
JD
D000328:Adult; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008297:Male; D008568:Memory / Q000502:physiology*; D012399:Rotation; D012438:Saccades / Q000502:physiology; D013028:Space Perception / Q000502:physiology*