Perceptual load affects spatial tuning of neuronal populations in human early visual cortex.
Withdrawal of attention from a visual scene as a result of perceptual load modulates overall levels of activity in human visual cortex [1], but its effects on cortical spatial tuning properties are unknown. Here we show attentional load at fixation affects the spatial tuning of population receptive fields (pRFs) in early visual cortex (V1-3) using functional magnetic resonance imaging (fMRI). We found that, compared to low perceptual load, high perceptual load yielded a 'blurrier' representation of the visual field surrounding the attended location and a centrifugal 'repulsion' of pRFs. Additional data and control analyses confirmed that these effects were neither due to changes in overall activity levels nor to eye movements. These findings suggest neural 'tunnel vision' as a form of distractor suppression under high perceptual load.
Institute of Cognitive Neuroscience, University College London, Alexandra House, 17 Queen Square, London WC1N 3AR, UK; Wellcome Trust Centre for Neuroimaging, University College London, Alexandra House, 17 Queen Square, London WC1N 3AR, UK; Cognitive Perceptual and Brain Sciences, University College London, Alexandra House, 17 Queen Square, London WC1N 3AR, UK. Electronic address: benjamindehaas@gmail.com.
Benjamin
B
de Haas
Institute of Cognitive Neuroscience, University College London, Alexandra House, 17 Queen Square, London WC1N 3AR, UK; Wellcome Trust Centre for Neuroimaging, University College London, Alexandra House, 17 Queen Square, London WC1N 3AR, UK; Cognitive Perceptual and Brain Sciences, University College London, Alexandra House, 17 Queen Square, London WC1N 3AR, UK; Institute of Ophthalmology, University College London, Alexandra House, 17 Queen Square, London WC1N 3AR, UK.
D Samuel
DS
Schwarzkopf
Institute of Cognitive Neuroscience, University College London, Alexandra House, 17 Queen Square, London WC1N 3AR, UK; Wellcome Trust Centre for Neuroimaging, University College London, Alexandra House, 17 Queen Square, London WC1N 3AR, UK; Institute of Ophthalmology, University College London, Alexandra House, 17 Queen Square, London WC1N 3AR, UK.
Elaine J
EJ
Anderson
Institute of Cognitive Neuroscience, University College London, Alexandra House, 17 Queen Square, London WC1N 3AR, UK; Wellcome Trust Centre for Neuroimaging, University College London, Alexandra House, 17 Queen Square, London WC1N 3AR, UK.
Geraint
G
Rees
D002452:Cell Count; D006801:Humans; D008279:Magnetic Resonance Imaging; D009474:Neurons / Q000166:cytology*; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*