A nested cortical hierarchy of neural states underlies event segmentation in the human brain

A fundamental aspect of human experience is that it is segmented into discrete events. This may be underpinned by transitions between distinct neural states. Using an innovative data-driven state segmentation method, we investigate how neural states are organized across the cortical hierarchy and where in cortex neural state and perceived event boundaries overlap. Our results show that neural state boundaries are organized in a temporal cortical hierarchy, with short states in primary sensory regions and long states in anterior temporal pole and lateral and medial prefrontal cortex. Neural state boundaries overlap with event boundaries across large parts of this hierarchy. State boundaries are shared within and between groups of brain regions that resemble well known functional networks, such as the default mode network that fractionates into two subnetworks – one fast, one slow. Together these findings suggest that a nested cortical hierarchy of neural states forms the basis of event segmentation.