Poster #: 51
Topic: Error signals
Friday, Sep 11, 2015
Prediction errors of visual content across eye movements and their modulation by inferred information in the blind spot
1Institute of Cognitive Science, University of Osnabrück, Osnabrück, Germany
2Institute of Cognitive Science, University of Osnabrück, Germany
The brain is proposed to operate through probabilistic inference, testing and refining predictions about the world. Here, we search for neural activity compatible with the violation of active predictions, learned from the contingencies between actions and the consequent changes in sensory input. We focused on vision, where eye-movements produce stimuli shifts that could, in principle, be predicted. We compared error signals to saccade-contingent changes of direct and indirect inputs, by contrasting the electroencephalographic (EEG) activity after saccades to a peripheral stimulus presented monocularly inside or outside the blind-spot. In some trials the stimulus remained the same pre and post eye-movement but in others it was exchanged. The EEG was analyzed using univariate general linear models, corrected for multiple comparison using threshold-free cluster based methods. We observed early (<250 ms) and late error signals (>250 ms) after stimulus change, indicating the violation of sensory and associative predictions respectively. Remarkably, the late P3-like response was diminished for blind-spot trials. These results indicate that predictive signals occur across multiple levels of the visual hierarchy, based on generative models that differentiate between signals that originate from the outside world and those that are inferred.