title: Parietal and early visual cortices encode working memory content across mental transformations.
abstract: Active and flexible manipulations of memory contents "in the mind's eye" are believed to occur in a dedicated neural workspace, frequently referred to as visual working memory. Such a neural workspace should have two important properties: The ability to store sensory information across delay periods and the ability to flexibly transform sensory information. Here we used a combination of functional MRI and multivariate decoding to indentify such neural representations. Subjects were required to memorize a complex artificial pattern for an extended delay, then rotate the mental image as instructed by a cue and memorize this transformed pattern. We found that patterns of brain activity already in early visual areas and posterior parietal cortex encode not only the initially remembered image, but also the transformed contents after mental rotation. Our results thus suggest that the flexible and general neural workspace supporting visual working memory can be realized within posterior brain regions.
authors.affiliation: Bernstein Center for Computational Neuroscience, Charité Universitätsmedizin, Berlin 10115, Germany; Berlin Center for Advanced Neuroimaging, Charité Universitätsmedizin, Berlin 10117, Germany. Electronic address: tbchristophel@gmail.com.
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Christophel
authors.affiliation: Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Radoslaw M
authors.initials: RM
authors.lastname: Cichy
authors.affiliation: Bernstein Center for Computational Neuroscience, Charité Universitätsmedizin, Berlin 10115, Germany; Berlin Center for Advanced Neuroimaging, Charité Universitätsmedizin, Berlin 10117, Germany; Berlin School of Mind and Brain, Humboldt Universität, Berlin 10099, Germany; Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany.
authors.forename: Martin N
authors.initials: MN
authors.lastname: Hebart
authors.affiliation: Bernstein Center for Computational Neuroscience, Charité Universitätsmedizin, Berlin 10115, Germany; Berlin Center for Advanced Neuroimaging, Charité Universitätsmedizin, Berlin 10117, Germany; Berlin School of Mind and Brain, Humboldt Universität, Berlin 10099, Germany; Cluster of Excellence NeuroCure, Charité Universitätsmedizin, Berlin 10117, Germany; Department of Neurology, Charité Universitätsmedizin, Berlin 10117, Germany; Department of Psychology, Humboldt Universität zu Berlin, Berlin 10099, Germany.
authors.forename: John-Dylan
authors.initials: JD
authors.lastname: Haynes
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007092:Imagination / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*; D055815:Young Adult
keywords: Mental rotation; Multivariate analyses; Short-term memory; Working memory; fMRI