Distributed cortical systems in visual short-term memory revealed by event-related functional magnetic resonance imaging.
The spatio-temporal distribution of brain activity as revealed by non-invasive functional imaging helps to elucidate the neuronal encoding and processing strategies required by complex cognitive tasks. We investigated visual short-term memory for objects, places and conjunctions in humans using event-related time-resolved functional magnetic resonance imaging that permitted segregation of encoding, retention and retrieval phases. All conditions were accompanied by the activation of a widespread network of parietal and prefrontal areas during the retention phase, but this retention-related activity showed additional modulations depending on task instructions. These modulations confirmed a posterior-anterior and right-left dissociation for spatial versus non-spatial memory and revealed that conjunction memory does not rely on a linear addition of the component processes.
Munk
Matthias H J
MH
Max-Planck-Institut für Hirnforschung, Deutschordenstrasse 46, D-60528 Frankfurt, Germany. munk@mpih-frankfurt.mpg.de
Linden
David E J
DE
Muckli
Lars
L
Lanfermann
Heinrich
H
Zanella
Friedhelm E
FE
Singer
Wolf
W
Goebel
Rainer
R
D000328:Adult; D001931:Brain Mapping; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010775:Photic Stimulation; D013028:Space Perception / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*