Virtual RealityDesigning a Spatial Navigation Intervention Protocol Informed by Region-specific Brain Activation for Mild Cognitive Impairment

Virtual reality maze session 1: Individualized, face-to-face introductory session to describe and answer questions about the protocol. Virtual reality EEG session 2 (baseline): Each session lasts 50 minutes. Initial maze complexity will be set at the lowest level (i.e., one turn to reach target). A maze will be repeated until performed without errors after which a new maze is introduced. The up-down transformed rule will be used to adjust complexity based on a participant's performance. Specifically, a three-up/one-down rule, meaning that for three consecutive error-free mazes the complexity of the maze will be adjusted by introducing an additional turn-to-target and for any error the number of turns to reach the target will be reduced by one. Virtual reality maze sessions 3-23 (no EEG): Participants take part in six sessions within 10 days over a 4-month period. Virtual reality-SN EEG sessions 12 \& 24: Participants are trained on the virtual reality maze while EEG is recorded.

A full-immersive virtual-reality environment where participants train ability to navigate and find their way through a maze in virtual reality has been developed. The virtual-reality environment is well-suited to maintain learner motivation throughout the intervention by providing appropriate challenges (i.e., maze complexity can be adjusted to the learner's progress), positive feedback (i.e., reaching the maze goal), and novelty (i.e., new mazes for each session). 50 different VR mazes, varying in difficulty from 1 to 4 intersections, have been built.