title: Dissociated α-band modulations in the dorsal and ventral visual pathways in visuospatial attention and perception.
abstract: Modulations of occipito-parietal α-band (8-14 Hz) power that are opposite in direction (α-enhancement vs. α-suppression) and origin of generation (ipsilateral vs. contralateral to the locus of attention) are a robust correlate of anticipatory visuospatial attention. Yet, the neural generators of these α-band modulations, their interdependence across homotopic areas, and their respective contribution to subsequent perception remain unclear. To shed light on these questions, we employed magnetoencephalography, while human volunteers performed a spatially cued detection task. Replicating previous findings, we found α-power enhancement ipsilateral to the attended hemifield and contralateral α-suppression over occipito-parietal sensors. Source localization (beamforming) analysis showed that α-enhancement and suppression were generated in 2 distinct brain regions, located in the dorsal and ventral visual streams, respectively. Moreover, α-enhancement and suppression showed different dynamics and contribution to perception. In contrast to the initial and transient dorsal α-enhancement, α-suppression in ventro-lateral occipital cortex was sustained and influenced subsequent target detection. This anticipatory biasing of ventro-lateral extrastriate α-activity probably reflects increased receptivity in the brain region specialized in processing upcoming target features. Our results add to current models on the role of α-oscillations in attention orienting by showing that α-enhancement and suppression can be dissociated in time, space, and perceptual relevance.
authors.affiliation: Department of Biological and Health Psychology, Autonoma University of Madrid, Madrid, Spain.
authors.forename: Almudena
authors.initials: A
authors.lastname: Capilla
authors.forename: Jan-Mathijs
authors.initials: JM
authors.lastname: Schoffelen
authors.forename: Gavin
authors.initials: G
authors.lastname: Paterson
authors.forename: Gregor
authors.initials: G
authors.lastname: Thut
authors.forename: Joachim
authors.initials: J
authors.lastname: Gross
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003463:Cues; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D009483:Neuropsychological Tests; D009778:Occipital Lobe / Q000502:physiology; D010775:Photic Stimulation; D013028:Space Perception / Q000502:physiology*; D013647:Task Performance and Analysis; D013997:Time Factors; D014795:Visual Pathways / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
keywords: alpha; beamforming; brain oscillations; magnetoencephalography; spatial orienting