Virtual training leads to real acute physical, cognitive and neural benefits on healthy adults: study protocol for a randomized-controlled trial

BACKGROUND Keeping a certain level of physical activity has beneficial effects on the body itself but also, surprisingly, on cognition: specifically, physical high-intensity intermittent aerobic exercise (HIE) can show improvement on cognitive executive functions. Although, in some cases performing strength or aerobic training is problematic or not feasible. Immersive virtual reality (IVR) can induce the illusory feeling of ownership and agency over a moving virtual body, showing therefore comparable physiological reactions: for example, if a subject is sitting on a chair but the own virtual body climbs a hill, the subject’s heart rate increases coherently, as if he’s actually walking. In this study, we want to investigate whether this same illusion can show beneficial consequences on the body but also on executive functions (using the colour-word matching Stroop task) and on its neural substrates (using the functional near infrared spectroscopy, fNIRS). METHODS In a cross-over randomized controlled trial, 30 healthy young adults will experience a HIE training in IVR (i.e., the virtual body will perform eight sets of 30 seconds of running followed by 30 seconds of slow walking, while the subject is completely still) according to two random-ordered conditions: during the experimental condition, the virtual body is displayed in the first-person perspective (1PP), while in the control condition, the virtual body is displayed in third-person perspective (3PP). To confirm that in 1PP (and not in 3PP) subjects have the illusion of ownership and agency over the virtual body, we will record the heart rate, in addition to subjective questionnaires. Before and after every IVR sessions (one week apart), we will measure cortical hemodynamic changes in the participants’ prefrontal cortex (PFC) using the fNIRS device during the Stroop task’s execution. DISCUSSION From a theoretical perspective, we could prove that the sense of body ownership and agency can modulate physical and cognitive parameters, even in absence of actual movements; from a clinical perspective, these results could be useful to train cognition and body simultaneously, in a completely safe environment. Trial registration University Hospital Medical Information Network Clinical Trial Registry, UMIN000034255. Registered on 1st October 2018.