Brain network organisation in the isolated hemisphere of people after hemispherotomy

Brisbane Convention & Exhibition Centre 

Cognition and behaviour are thought to be underpinned by seven segregated brain networks, ranging from the sensory functions of the visual network to the intrinsic mental processes, such as consciousness, associated with the default-mode network. However, it remains uncertain whether the functional integrity of these networks persists when the brain is devoid of external inputs. To explore this, we examine the functional organization of individual brain hemispheres in individuals who have undergone hemispherotomy for pharmacoresistant epilepsy. Our findings reveal that the intrinsic functional organization of the seven hierarchically ordered macroscale networks is preserved in the isolated hemisphere after hemispherotomy. However, both isolated and connected hemispheres exhibit reduced network segregation and higher interindividual variability compared to healthy brains. These results suggest that isolated hemispheres retain functional integrity, prompting further exploration into their cognitive capabilities and their potential to be “islands of awareness”.