Evidence for early and late prediction error-associated ERP responses during probabilistic cueing.

Probabilistic relationships are omnipresent in our sensory environment. According to some predictive coding models, the processing of deviations from expectation should be accompanied by enhanced neuronal responses, reflecting a prediction error, while expected stimuli should lead to suppression of brain responses. However, probabilistic cueing designs show no clear picture regarding prediction error and expectation suppression. Here, we measured event-related potentials (ERPs) while participants were presented with a probabilistic cueing procedure with low, high, or equal-probable stimuli, while the task relevance of the probabilistic relations was varied. Our data show enhanced ERPs to infrequent stimuli in early (increased negative amplitudes over posterior electrodes) and late (increased positive amplitudes over central electrodes) time windows, driven by a prediction error and not by expectation suppression. While early visual responses are independent of task-relevance of predictive information, later and hierarchically higher effects are potentiated if predictive information is explicitly attended.