title: Silent Expectations: Dynamic Causal Modeling of Cortical Prediction and Attention to Sounds That Weren't.
abstract: There is increasing evidence that human perception is realized by a hierarchy of neural processes in which predictions sent backward from higher levels result in prediction errors that are fed forward from lower levels, to update the current model of the environment. Moreover, the precision of prediction errors is thought to be modulated by attention. Much of this evidence comes from paradigms in which a stimulus differs from that predicted by the recent history of other stimuli (generating a so-called "mismatch response"). There is less evidence from situations where a prediction is not fulfilled by any sensory input (an "omission" response). This situation arguably provides a more direct measure of "top-down" predictions in the absence of confounding "bottom-up" input. We applied Dynamic Causal Modeling of evoked electromagnetic responses recorded by EEG and MEG to an auditory paradigm in which we factorially crossed the presence versus absence of "bottom-up" stimuli with the presence versus absence of "top-down" attention. Model comparison revealed that both mismatch and omission responses were mediated by increased forward and backward connections, differing primarily in the driving input. In both responses, modeling results suggested that the presence of attention selectively modulated backward "prediction" connections. Our results provide new model-driven evidence of the pure top-down prediction signal posited in theories of hierarchical perception, and highlight the role of attentional precision in strengthening this prediction.
  
  
  
  Human auditory perception is thought to be realized by a network of neurons that maintain a model of and predict future stimuli. Much of the evidence for this comes from experiments where a stimulus unexpectedly differs from previous ones, which generates a well-known "mismatch response." But what happens when a stimulus is unexpectedly omitted altogether? By measuring the brain's electromagnetic activity, we show that it also generates an "omission response" that is contingent on the presence of attention. We model these responses computationally, revealing that mismatch and omission responses only differ in the location of inputs into the same underlying neuronal network. In both cases, we show that attention selectively strengthens the brain's prediction of the future.
authors: School of Computing, University of Kent, Chatham Maritime ME4 4AG, United Kingdom, Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0QQ, United Kingdom, sc785@kent.ac.uk.
authors: Srivas
authors: 0000-0002-6840-2941
authors: S
authors: Chennu
authors: Medical Research Council Cognition and Brain Sciences Unit, Cambridge CB2 7EF, United Kingdom.
authors: Valdas
authors: V
authors: Noreika
authors: Institute of Neuroscience, Université Catholique de Louvain, B-1200 Brussels, Belgium.
authors: David
authors: 0000-0002-2833-0437
authors: D
authors: Gueorguiev
authors: Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, 8000 Aarhus, Denmark, Centre for Cognition and Decision Making, National Research University Higher School of Economics, 101000 Moscow, Russia, and.
authors: Yury
authors: Y
authors: Shtyrov
authors: Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom.
authors: Tristan A
authors: TA
authors: Bekinschtein
authors: Medical Research Council Cognition and Brain Sciences Unit, Cambridge CB2 7EF, United Kingdom.
authors: Richard
authors: 0000-0002-0712-2639
authors: R
authors: Henson
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000166:cytology / Q000000981:diagnostic imaging / Q000502:physiology*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D008959:Models, Neurological; D017711:Nonlinear Dynamics; D013016:Sound; D055815:Young Adult
keywords: dynamic causal modeling; electroencephalography; hierarchical predictive coding; magnetoencephalography; mismatch effect; omission effect