title: The neural encoding of guesses in the human brain.
abstract: Human perception depends heavily on the quality of sensory information. When objects are hard to see we often believe ourselves to be purely guessing. Here we investigated whether such guesses use brain networks involved in perceptual decision making or independent networks. We used a combination of fMRI and pattern classification to test how visibility affects the signals, which determine choices. We found that decisions regarding clearly visible objects are predicted by signals in sensory brain regions, whereas different regions in parietal cortex became predictive when subjects were shown invisible objects and believed themselves to be purely guessing. This parietal network was highly overlapping with regions, which have previously been shown to encode free decisions. Thus, the brain might use a dedicated network for determining choices when insufficient sensory information is available.
authors.affiliation: Max-Planck-Institute for Human Cognitive and Brain Sciences, Stephanstrasse 1A, 04109 Leipzig, Germany. sbode@unimelb.edu.au
authors.forename: Stefan
authors.initials: S
authors.lastname: Bode
authors.forename: Carsten
authors.initials: C
authors.lastname: Bogler
authors.forename: Chun Siong
authors.initials: CS
authors.lastname: Soon
authors.forename: John-Dylan
authors.initials: JD
authors.lastname: Haynes
mesh_terms: D000328:Adult; D002755:Choice Behavior / Q000502:physiology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*