Cortical Coupling Reflects Bayesian Belief Updating in the Deployment of Spatial Attention.
The deployment of visuospatial attention and the programming of saccades are governed by the inferred likelihood of events. In the present study, we combined computational modeling of psychophysical data with fMRI to characterize the computational and neural mechanisms underlying this flexible attentional control. Sixteen healthy human subjects performed a modified version of Posner's location-cueing paradigm in which the percentage of cue validity varied in time and the targets required saccadic responses. Trialwise estimates of the certainty (precision) of the prediction that the target would appear at the cued location were derived from a hierarchical Bayesian model fitted to individual trialwise saccadic response speeds. Trial-specific model parameters then entered analyses of fMRI data as parametric regressors. Moreover, dynamic causal modeling (DCM) was performed to identify the most likely functional architecture of the attentional reorienting network and its modulation by (Bayes-optimal) precision-dependent attention. While the frontal eye fields (FEFs), intraparietal sulcus, and temporoparietal junction (TPJ) of both hemispheres showed higher activity on invalid relative to valid trials, reorienting responses in right FEF, TPJ, and the putamen were significantly modulated by precision-dependent attention. Our DCM results suggested that the precision of predictability underlies the attentional modulation of the coupling of TPJ with FEF and the putamen. Our results shed new light on the computational architecture and neuronal network dynamics underlying the context-sensitive deployment of visuospatial attention.


CONCLUSIONS
Spatial attention and its neural correlates in the human brain have been studied extensively with the help of fMRI and cueing paradigms in which the location of targets is pre-cued on a trial-by-trial basis. One aspect that has so far been neglected concerns the question of how the brain forms attentional expectancies when no a priori probability information is available but needs to be inferred from observations. This study elucidates the computational and neural mechanisms under which probabilistic inference governs attentional deployment. Our results show that Bayesian belief updating explains changes in cortical connectivity; in that directional influences from the temporoparietal junction on the frontal eye fields and the putamen were modulated by (Bayes-optimal) updates.
Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, United Kingdom, Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, 52425 Jülich, Germany, s.vossel@fz-juelich.de.
Simone
http://orcid.org/0000-0002-6351-8849
S
Vossel
Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, United Kingdom, Max Planck University College London Centre for Computational Psychiatry and Ageing Research, London WC1B 5EH, United Kingdom, Translational Neuromodeling Unit, Institute for Biomedical Engineering, University of Zurich and Eidgenössische Technische Hochschule (ETH) Zurich, 8032 Zurich, Switzerland, and.
Christoph
http://orcid.org/0000-0003-4079-5453
C
Mathys
Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, United Kingdom, Translational Neuromodeling Unit, Institute for Biomedical Engineering, University of Zurich and Eidgenössische Technische Hochschule (ETH) Zurich, 8032 Zurich, Switzerland, and Max Planck Institute for Metabolism Research, 50931 Cologne, Germany.
Klaas E
http://orcid.org/0000-0002-8594-9092
KE
Stephan
Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, United Kingdom.
Karl J
http://orcid.org/0000-0001-7984-8909
KJ
Friston
D000328:Adult; D001288:Attention / Q000502:physiology*; D001499:Bayes Theorem; D003198:Computer Simulation; D003463:Cues; D005260:Female; D006801:Humans; D008959:Models, Neurological; D009473:Neuronal Plasticity / Q000502:physiology; D011699:Putamen / Q000502:physiology*; D012438:Saccades / Q000502:physiology*; D065855:Spatial Processing / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*; D055815:Young Adult
Bayesian inference; attentional networks; fMRI; saccades; spatial cueing