title: Spatiotopic coding of BOLD signal in human visual cortex depends on spatial attention.
abstract: The neural substrate of the phenomenological experience of a stable visual world remains obscure. One possible mechanism would be to construct spatiotopic neural maps where the response is selective to the position of the stimulus in external space, rather than to retinal eccentricities, but evidence for these maps has been inconsistent. Here we show, with fMRI, that when human subjects perform concomitantly a demanding attentive task on stimuli displayed at the fovea, BOLD responses evoked by moving stimuli irrelevant to the task were mostly tuned in retinotopic coordinates. However, under more unconstrained conditions, where subjects could attend easily to the motion stimuli, BOLD responses were tuned not in retinal but in external coordinates (spatiotopic selectivity) in many visual areas, including MT, MST, LO and V6, agreeing with our previous fMRI study. These results indicate that spatial attention may play an important role in mediating spatiotopic selectivity.
authors.affiliation: Department of Psychology, Università Degli Studi di Firenze, Florence, Italy.
authors.forename: Sofia
authors.initials: S
authors.lastname: Crespi
authors.forename: Laura
authors.initials: L
authors.lastname: Biagi
authors.forename: Giovanni
authors.initials: G
authors.lastname: d'Avossa
authors.forename: David C
authors.initials: DC
authors.lastname: Burr
authors.forename: Michela
authors.initials: M
authors.lastname: Tosetti
authors.forename: Maria Concetta
authors.initials: MC
authors.lastname: Morrone
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D005133:Eye Movements / Q000502:physiology; D005260:Female; D005584:Fovea Centralis / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009039:Motion Perception / Q000502:physiology; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D014793:Visual Cortex / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
chemical_list: D010100:Oxygen