title: Pupillometric evidence for the decoupling of attention from perceptual input during offline thought.
abstract: Accumulating evidence suggests that the brain can efficiently process both external and internal information. The processing of internal information is a distinct "offline" cognitive mode that requires not only spontaneously generated mental activity; it has also been hypothesized to require a decoupling of attention from perception in order to separate competing streams of internal and external information. This process of decoupling is potentially adaptive because it could prevent unimportant external events from disrupting an internal train of thought. Here, we use measurements of pupil diameter (PD) to provide concrete evidence for the role of decoupling during spontaneous cognitive activity. First, during periods conducive to offline thought but not during periods of task focus, PD exhibited spontaneous activity decoupled from task events. Second, periods requiring external task focus were characterized by large task evoked changes in PD; in contrast, encoding failures were preceded by episodes of high spontaneous baseline PD activity. Finally, high spontaneous PD activity also occurred prior to only the slowest 20% of correct responses, suggesting high baseline PD indexes a distinct mode of cognitive functioning. Together, these data are consistent with the decoupling hypothesis, which suggests that the capacity for spontaneous cognitive activity depends upon minimizing disruptions from the external world.
authors.affiliation: Department of Social Neuroscience, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany. smallwood@cbs.mpg.de
authors.forename: Jonathan
authors.initials: J
authors.lastname: Smallwood
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Brown
authors.forename: Christine
authors.initials: C
authors.lastname: Tipper
authors.forename: Barry
authors.initials: B
authors.lastname: Giesbrecht
authors.forename: Michael S
authors.initials: MS
authors.lastname: Franklin
authors.forename: Michael D
authors.initials: MD
authors.lastname: Mrazek
authors.forename: Jean M
authors.initials: JM
authors.lastname: Carlson
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Schooler
mesh_terms: D000293:Adolescent; D001288:Attention / Q000502:physiology*; D002755:Choice Behavior / Q000502:physiology; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D008960:Models, Psychological; D009043:Motor Activity / Q000502:physiology; D010465:Perception / Q000502:physiology*; D011680:Pupil / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013647:Task Performance and Analysis; D013850:Thinking / Q000502:physiology*; D055815:Young Adult