abstract Karsten Rauss

Karsten Rauss (Institute of Medical Psychology and Behavioral Neurobiology, University of Tuebingen, Germany)

Top-down effects on early visual processing: a case of predictive coding?

A growing body of evidence supports the notion that the earliest stages of sensory processing in the cerebral cortex are modulated by top-down factors such as attention. Based on a review of recent EEG studies in humans, including results from our group, I will argue that such early gating influences are best understood within a predictive-coding framework. One basic claim of predictive-coding theories is that perceptual processing is not primarily concerned with forming a comprehensive representation of the sensory environment, but with matching stimulus information to internally generated predictions. Such predictions are thought to be generated in higher cortical regions that pass them on to lower areas such as the primary visual cortex. Conversely, bottom-up processing from lower to higher areas is assumed to reflect prediction error signals which are then used to refine predictions. I will outline how this theoretical framework can explain discrepancies in the literature on early visual processing and how it may aid the integration of research on basic sensory processing and higher cognitive functions.