This workshop brings together researchers and practitioners in the mixed reality community to brainstorm how sensing the brain can be useful for VR/AR/XR applications. A moderated panel discussion by invited panelists will seed ideas around how brain sensing can be used in VR (e.g., cybersickness, presence, cognitive load), what are the challenges in doing this type of sensing in VR/AR/XR (e.g., hardware constraints, movement, real-time analysis), how to do it responsibly (neurorights, privacy, anonymization, open datasets). A poster session will allow participants to share their research and/or perspectives. The goal of this workshop will be to create a research vision to inspire the community and to catalyze the exploration of a new scientific frontier.