Neural correlates of virtual hand movements using ecologically valid tasks

The aim of the present study was to investigate the effects of realistic and more unrealistic, abstract virtual hand models on neuronal and behavioral responses in virtual reality (VR) using ecologically valid virtual hand movement tasks. 36 participants performed a button press reaction time task, which was a type of a virtual oddball-task, and a virtual object grip task in VR, both performed with their non-dominant hand. Both tasks were performed once with a realistic, human-like hand model and once with an abstract schematic hand model, i.e., a skeletal hand model. Neuronal responses during the VR tasks were assessed using electroencephalography (EEG). The virtual button press task elicited expected event-related potentials (P300) in the EEG comparable to real-world oddball-tasks, showing ecological validity of this VR task. No differences in neuronal or behavioral responses between realistic and skeletal virtual hand models were observed in the button press task. For the virtual object grip task, activation of motor brain areas was stronger when performing the task with a realistic than with a skeletal hand model. Our results show that more complex VR hand movement tasks can elicit neuronal responses comparable to prior real-world tasks. While prior VR studies using relatively simple virtual hand movement tasks found no differences in neuronal responses between realistic and more abstract hand model conditions, we showed that the design of virtual hand models has an effect on motor cortex activation during more complex and ecologically valid virtual tasks, which might have an impact on the design of virtual hand models in future clinical VR applications.