title: Causal involvement of visual area MT in global feature-based enhancement but not contingent attentional capture.
abstract: When visual attention is set for a particular target feature, such as color or shape, neural responses to that feature are enhanced across the visual field. This global feature-based enhancement is hypothesized to underlie the contingent attentional capture effect, in which task-irrelevant items with the target feature capture spatial attention. In humans, however, different cortical regions have been implicated in global feature-based enhancement and contingent capture. Here, we applied intermittent theta-burst stimulation (iTBS) to assess the causal roles of two regions of extrastriate cortex - right area MT and the right temporoparietal junction (TPJ) - in both global feature-based enhancement and contingent capture. We recorded cortical activity using EEG while participants monitored centrally for targets defined by color and ignored peripheral checkerboards that matched the distractor or target color. In central vision, targets were preceded by colored cues designed to capture attention. Stimuli flickered at unique frequencies, evoking distinct cortical oscillations. Analyses of these oscillations and behavioral performance revealed contingent capture in central vision and global feature-based enhancement in the periphery. Stimulation of right area MT selectively increased global feature-based enhancement, but did not influence contingent attentional capture. By contrast, stimulation of the right TPJ left both processes unaffected. Our results reveal a causal role for the right area MT in feature-based attention, and suggest that global feature-based enhancement does not underlie the contingent capture effect.
authors.affiliation: The University of Queensland, School of Psychology, St Lucia 4072, Australia; The University of Queensland, Queensland Brain Institute, St Lucia 4072, Australia. Electronic address: david.ross.painter@gmail.com.
authors.forename: David R
authors.initials: DR
authors.lastname: Painter
authors.affiliation: The University of Queensland, School of Psychology, St Lucia 4072, Australia.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Dux
authors.affiliation: The University of Queensland, School of Psychology, St Lucia 4072, Australia; The University of Queensland, Queensland Brain Institute, St Lucia 4072, Australia.
authors.forename: Jason B
authors.initials: JB
authors.lastname: Mattingley
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D003118:Color Perception / Q000502:physiology; D003463:Cues; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000502:physiology; D010775:Photic Stimulation; D013702:Temporal Lobe / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Area MT; Frequency tagging; Frontoparietal network; Selective attention; Temporoparietal junction; Transcranial magnetic stimulation