Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.07.04.188235v1?rss=1 Authors: Liu, W., Kohn, N., Fernandez, G. Abstract: Flexible behavior requires switching between different task demands. It is known that such task-switching is associated with costs in terms of slowed reaction time, reduced accuracy, or both. The neural correlates of task-switching have usually been studied by requiring participants to switch between distinct tasks that recruit different brain networks. Here, we investigated the transition of neural states underlying switching between two memory-related processes with opposite task demands (i.e., memory retrieval and memory suppression). We investigated 26 healthy participants who performed a Think/No-Think task while being in the fMRI scanner. Behaviorally, we show that it was more difficult for participants to suppress unwanted memories when a No-Think was preceded by a Think trial instead of another No-Think trial. Neurally, we demonstrate that Think-to-No-Think switches were associated with an increase in control-related and a decrease in memory-related brain activity. Neural representations of task demand, assessed by decoding accuracy, were lower immediately after task switching compared to the non-switch transitions, suggesting a switch-induced delay in the neural transition towards the required task demand. This suggestion is corroborated by an association between demand-specific representational strength and demand-specific performance in switch trials. Taken together, we propose that the brain's delayed transition of neural states towards the task demand at hand is associated with a switch cost leading to less successful memory suppression. Copy rights belong to original authors. Visit the link for more info