TY - JOUR T1 - Sedation modulates fronto-temporal predictive coding circuits and the double surprise acceleration effect JF - bioRxiv DO - 10.1101/2020.02.21.959171 SP - 2020.02.21.959171 AU - Adrien Witon AU - Amirali Shirazibehehsti AU - Jennifer Cooke AU - Alberto Aviles AU - Ram Adapa AU - David K. Menon AU - Srivas Chennu AU - Tristan Bekinschtein AU - Jose David Lopez AU - Vladimir Litvak AU - Ling Li AU - Karl Friston AU - Howard Bowman Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/02/24/2020.02.21.959171.abstract N2 - Two important theories in cognitive neuroscience are predictive coding and the global workspace theory. A key research task is to understand how these two theories relate to one another, and particularly, how the brain transitions from a predictive early state to the eventual engagement of a brain-scale state (the global workspace). To address this question, we present a source-localisation of EEG responses evoked by the local-global task – an experimental paradigm that engages a predictive hierarchy, which encompasses the global workspace. The results of our source reconstruction suggest three-phases of processing. The first phase involves the sensory (here auditory) regions of the superior temporal lobe and predicts sensory regularities over a short timeframe (as per the local effect). The third phase is brain-scale, involving inferior frontal, as well as inferior and superior parietal regions; consistent with a global neuronal workspace (as per the global effect). Crucially, our analysis suggests that there is an intermediate (second) phase, involving modulatory interactions between inferior frontal and superior temporal regions. Furthermore, sedation with propofol reduces modulatory interactions in the second phase. This selective effect is consistent with a predictive coding explanation of sedation, with propofol acting on descending predictions of the precision of prediction errors; thereby constraining access to the global neuronal workspace. ER -