Extended-Reality e-Pong Task

The present experimental study aims to investigate whether nocebo-inducing verbal instructions can influence motor performance and subjective experience during the execution of a virtual movement task. To achieve this, the Brazilian Institute of Neuroscience and Neurotechnology Extended Reality System (BRAINN_XR) system will be used through the e-Pong task, in which participants control virtual bars using upper-limb movements to intercept a moving ball. Healthy participants will be randomly assigned to either a control group or a manipulation (nocebo) group. Following a familiarization phase and two baseline task blocks, participants in the manipulation group will receive standardized verbal instructions suggesting that abrupt movements may cause shoulder discomfort or pain, whereas the control group will continue the task without additional information. Performance will be assessed by the number of errors during the virtual task, while subjective measures will include perceived pain, pain-related concern, task difficulty, and body vigilance. It is hypothesized that participants exposed to the nocebo instructions will demonstrate poorer motor performance after the manipulation, as well as higher levels of perceived pain and concern during task execution compared to the control group.