How older and younger adults aim in virtual reality with and without feedback

This study has two main objectives: First, to better understand how a motor task commonly used by researchers, known as the Fitts' task, is performed in virtual reality. It consists of reaching a target, which may be large or small, by extending the right arm. This task is similar to movements commonly performed in everyday life. It is also increasingly used in virtual reality video games designed to train older adults or patients with functional limitations. Secondly, the investigators aim to describe how age influences performance in this task by comparing young adults and older adults. This can help better adapt the protocols used in virtual reality to the characteristics of users. It is of particular interest how movements change when the task becomes more difficult, whether these changes differ between young adults and older adults, and whether the information and feedback provided through virtual reality can improve the quality of motor performance. What is expected of participants: Participants will be seated comfortably, wearing a lightweight virtual reality headset and holding a controller in their right hand that will be used to reach for a target by keeping the controller within the target for about one second. The targets will vary in size, so some trials will seem easier and others more difficult. The task is simply to move as quickly as possible while remaining accurate (hitting the target). This instruction is important, and the experimenter will repeat it regularly during the experiment. The task will be performed under different conditions: sometimes participants will see the actual configuration of the experimental device in the physical world through the headset, and other times they will see the same configuration presented in virtual reality. In some virtual reality conditions, participants will also receive additional visual information indicating whether the target has been hit correctly. Short breaks are scheduled at regular intervals. Additional breaks can be asked for at any time when needed. The most important point is to avoid any fatigue or discomfort. If participants experience any, they are asked and encouraged to inform the experimenter. Before starting the experiment, participants will undergo a short training session to familiarize themselves with the task and the device.