Effects of pseudoexperience on the understanding of hemiplegic movements in physical therapists: An fMRI study

Physical therapists (PTs) are required to obtain an accurate understanding of the physical and mental states of their patients through observational assessment. To perform comprehensive observational assessments of patients' movements, PTs likely need to engage their own neural systems involved in action understanding and theory of mind, such as the action observation network (AON) and the right temporoparietal junction (rTPJ). Both systems are modulated by the observer's actual experience with the observed movements. Although, most PTs do not have physical experience with neurological disabilities, they routinely examine hemiplegic movements in stroke patients, and are thus considered to have acquired pseudoexperience with hemiplegia. We hypothesized that the PTs' pseudoexperience with hemiplegia would modulate the neural system associated with the understanding of others to elaborately comprehend the physical and mental states associated with hemiplegia. To investigate our hypothesis, we recruited 19 PTs and 19 naïve participants (NPs) to undergo functional MRI (fMRI) for cortical activity measurement while viewing videos of hemiplegic (HHM) and non-hemiplegic (non-HHM) hand movements. The participants subsequently viewed the same videos again outside the MRI scanner, and evaluated the observed hand movements via a questionnaire. Compared to the NPs, the PTs showed greater activation in the AON and rTPJ while observing HHMs. Psychophysiological interaction analyses revealed increased connectivity between the rTPJ and AON when the PTs viewed the HHMs. Behavioral analyses further indicated that the PTs more accurately assessed feeling states associated with HHMs than did NPs. These findings suggest that the PTs' pseudoexperience modulates the AON and rTPJ, enabling them to better understand hemiplegia-associated feeling states.