From perceiving to acting - action representations and their clinical relevance for the assessment and rehabilitation of post-stroke neglect/inattention

Efficient interaction with the world depends on tight coordination between perception and action. After brain injury, particularly stroke, this coordination is often disrupted, leading to difficulties in object use, spatial attention, and everyday function. Understanding how the brain normally links visual input to skilled action is therefore a key challenge for clinical neuroscience. The human brain contains multiple visual regions that respond selectively to hands and tools, spanning both visual and sensorimotor cortex. These responses are often interpreted as reflecting automatic, action-related processing of objects. Yet a critical question remains: what, exactly, is represented in these visually evoked signals? In this talk, I will present a series of neuroimaging studies examining how the brain represents action knowledge across different tasks. Our findings show that visual hand-selective cortex contains representations of how the hand should be shaped to interact with tools that are evoked automatically and, in a task-independent way. These results challenge a strict separation between perception and action systems and suggest that visual hand-selective cortex plays an active role in linking perception to skilled action. I will conclude by describing how this work is being translated into new cognitive assessments and rehabilitation methods, and a large-scale clinical trial in stroke rehabilitation, with a focus on spatial inattention/neglect (a lack of awareness of the side space opposite to the side of the stroke, usually the side where patients also lost their movement).