title: Spatiotopic updating across saccades revealed by spatially-specific fMRI adaptation.
abstract: Brain representations of visual space are predominantly eye-centred (retinotopic) yet our experience of the world is largely world-centred (spatiotopic). A long-standing question is how the brain creates continuity between these reference frames across successive eye movements (saccades). Here we use functional magnetic resonance imaging (fMRI) to address whether spatially specific repetition suppression (RS) is evident during trans-saccadic perception. We presented two successive Gabor patches (S1 and S2) in either the upper or lower visual field, left or right of fixation. Spatial congruency was manipulated by having S1 and S2 occur in the same or different upper/lower visual field. On half the trials, a saccade was cued between S1 and S2, placing spatiotopic and retinotopic reference frames in opposition. Equivalent RS was observed in the posterior parietal cortex and frontal eye fields when S1-S2 were spatiotopically congruent, irrespective of whether retinotopic and spatiotopic coordinates were in accord or were placed in opposition by a saccade. Additionally the post-saccadic response to S2 demonstrated spatially-specific RS in retinotopic visual regions, with stronger RS in extrastriate than striate cortex. Collectively, these results are consistent with a robust trans-saccadic spatial updating mechanism for object position that directly influences even the earliest levels of visual processing.
authors.affiliation: Center for Mind/Brain Sciences, University of Trento, Trento 38068, Italy. Electronic address: Scott.fairhall@unitn.it.
authors.forename: Scott L
authors.initials: SL
authors.lastname: Fairhall
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Schwarzbach
authors.affiliation: Royal Holloway University of London, Department of Psychology, Surrey, UK.
authors.forename: Angelika
authors.initials: A
authors.lastname: Lingnau
authors.affiliation: Center for Neuroscience and Cognitive Systems@UniTn, Italian Institute of Technology, Trento 38068, Italy.
authors.forename: Martijn Gerbrand
authors.initials: MG
authors.lastname: Van Koningsbruggen
authors.affiliation: Center for Mind/Brain Sciences, University of Trento, Trento 38068, Italy.
authors.forename: David
authors.initials: D
authors.lastname: Melcher
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010296:Parietal Lobe / Q000000981:diagnostic imaging / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D012438:Saccades / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D014793:Visual Cortex / Q000000981:diagnostic imaging / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*