Allocentric spatial memory activation of the hippocampal formation measured with fMRI.
Hippocampal activation was investigated, comparing allocentric and egocentric spatial memory. Healthy participants were immersed in a virtual reality circular arena, with pattern-rendered walls. In a viewpoint-independent task, they moved toward a pole, which was then removed. They were relocated to another position and had to move to the prior location of the pole. For viewpoint-dependent memory, the participants were not moved to a new starting point, but the patterns were rotated to prevent them from indicating the final position. Hippocampal and parahippocampal activation were found in the viewpoint-independent memory encoding phase. Viewpoint-dependent memory did not result in such activation. These results suggest differential activation of the hippocampal formation during allocentric encoding, in partial support of the spatial mapping hypothesis as applied to humans.
King's College London, London, United Kingdom. d.parslow@iop.kcl.ac.uk
David M
DM
Parslow
David
D
Rose
Barbara
B
Brooks
Simon
S
Fleminger
Jeffrey A
JA
Gray
Vincent
V
Giampietro
Michael J
MJ
Brammer
Steven
S
Williams
David
D
Gasston
Christopher
C
Andrew
Goparlen N
GN
Vythelingum
Glafkos
G
Loannou
Andrew
A
Simmons
Robin G
RG
Morris
D000328:Adult; D001931:Brain Mapping; D002531:Cerebellum / Q000502:physiology; D002540:Cerebral Cortex / Q000502:physiology*; D003463:Cues; D004292:Dominance, Cerebral / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall / Q000502:physiology; D008875:Middle Aged; D009415:Nerve Net / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D020534:Parahippocampal Gyrus / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology; D012016:Reference Values; D012153:Retention, Psychology / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D013788:Thalamus / Q000502:physiology; D014584:User-Computer Interface