title: A Unified attentional bottleneck in the human brain.
abstract: Human information processing is characterized by bottlenecks that constrain throughput. These bottlenecks limit both what we can perceive and what we can act on in multitask settings. Although perceptual and response limitations are often attributed to independent information processing bottlenecks, it has recently been suggested that a common attentional limitation may be responsible for both. To date, however, evidence supporting the existence of such a "unified" bottleneck has been mixed. Here, we tested the unified bottleneck hypothesis using time-resolved fMRI. Experiment 1 isolated brain regions involved in the response selection bottleneck that limits speeded dual-task performance. These same brain regions were not only engaged by a perceptual encoding task in Experiment 2, their activity also tracked delays to a speeded decision-making task caused by concurrent perceptual encoding (Experiment 3). We conclude that a unified attentional bottleneck, including the inferior frontal junction, superior medial frontal cortex, and bilateral insula, temporally limits operations as diverse as perceptual encoding and decision-making.
authors.affiliation: Department of Psychology, Vanderbilt Vision Research Center, Vanderbilt University, Nashville, TN 37240, USA. mtombu@gmail.com
authors.forename: Michael N
authors.initials: MN
authors.lastname: Tombu
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Asplund
authors.forename: Paul E
authors.initials: PE
authors.lastname: Dux
authors.forename: Douglass
authors.initials: D
authors.lastname: Godwin
authors.forename: Justin W
authors.initials: JW
authors.lastname: Martin
authors.forename: René
authors.initials: R
authors.lastname: Marois
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D054022:Cerebrum; D003657:Decision Making / Q000502:physiology; D005260:Female; D005625:Frontal Lobe; D006801:Humans; D008279:Magnetic Resonance Imaging; D008606:Mental Processes / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D013997:Time Factors; D055815:Young Adult