Alessandro Tavano¹, Erich Schröger², Burkhard Maess³
¹Boston University, ²Institute of Psychology, University of Leipzig, ³Institute for Human Cognitive and Brain Sciences
Active theories of perception suggest that the brain exploits sensory inferences based on stimulus expectancies to best model the current state of affairs in the world. Neural responses to omitted, but highly expected stimuli appear to resemble to a degree the response to the actual stimuli, suggesting activation of deputy sensory cortices. We used human EEG (Study 1, 17 participants) and MEG (Study 2, 20 participants) to test the extent of response “resemblance”, by directly comparing predictable vs. unpredictable deviant pure tones with their (rare) omissions. We observed nearly identical evoked responses to highly predictable stimuli and their omissions in the sensory space for EEG, and in the source space for MEG, locating the sources within the primary auditory cortices. Responses to unpredictable stimuli and their omissions differed significantly. We take this as evidence for a virtually perfect auditory prediction representation by our auditory cortices, overriding the concept of “stimulus template”, traditionally understood as an abstract or subsampled sensory representation. We argue that auditory predictions are precise (point-wise) neural simulations.
Keywords: Prediction, Omission, Auditory Cortex