title: The role of the pulvinar in distractor processing and visual search.
abstract: The pulvinar nuclei of the thalamus are hypothesized to coordinate attentional selection in the visual cortex. Different models have, however, been proposed for the precise role of the pulvinar in attention. One proposal is that the pulvinar mediates shifts of spatial attention; a different proposal is that it serves the filtering of distractor information. At present, the relation between these possible operations and their relative importance in the pulvinar remains unresolved. We address this issue by contrasting these proposals in two fMRI experiments. We used a visual search paradigm that permitted us to dissociate neural activity reflecting shifts of attention from activity underlying distractor filtering. We find that distractor filtering, but not the operation of shifting attention, is associated with strong activity enhancements in dorsal and ventral regions of the pulvinar as well as in early visual cortex areas including the primary visual cortex. Our observations indicate that distractor filtering is the preponderant attentional operation subserved by the pulvinar, presumably mediated by a modulation of processing in visual areas where spatial resolution is sufficiently high to separate target from distractor input.
authors.affiliation: Leibniz Institute for Neurobiology, Magdeburg, Germany.
authors.forename: Hendrick
authors.initials: H
authors.lastname: Strumpf
authors.forename: George R
authors.initials: GR
authors.lastname: Mangun
authors.forename: Carsten N
authors.initials: CN
authors.lastname: Boehler
authors.forename: Christian
authors.initials: C
authors.lastname: Stoppel
authors.forename: Mircea A
authors.initials: MA
authors.lastname: Schoenfeld
authors.forename: Hans-Jochen
authors.initials: HJ
authors.lastname: Heinze
authors.forename: Jens-Max
authors.initials: JM
authors.lastname: Hopf
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D005133:Eye Movements; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009949:Orientation / Q000502:physiology; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D020649:Pulvinar / Q000098:blood supply / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D014793:Visual Cortex / Q000098:blood supply / Q000502:physiology*; D014795:Visual Pathways / Q000098:blood supply / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen