The Primate Virtual Star Maze task can be varied in terms of design and parameters assessed in an investigation. In general, the protocol involves shaping trials and the Star Maze trials. The shaping trials help familiarize the subject with the equipment, virtual environments, and virtual navigation protocol using reward incentives. The Star Maze trials are usually reward-based trials where the subject is tasked with finding the correct arm. The following is a sample protocol for Virtual Star Maze task:

• Shaping Trials: In order to familiarize the subjects with the VR set-up, animals are first trained to find reward targets by controlling a virtual sphere in a two-dimensional virtual environment. Following the successful learning of the 2D task, animals are trained in a Virtual Y-Maze. Initially, animals are trained to approach the sphere in this environment without any cues present. Next, landmarks are introduced into the maze along with the sphere, and animals are tasked to approach the sphere. These trials are then followed by test trials wherein the subjects are tasked with approaching the landmark where the sphere was last present in order to receive a reward.
• Virtual Star Maze Trials: Following successful shaping trials, animals are introduced to the Virtual Star Maze with the animal starting in one of the arms facing the maze. The animals are tasked with finding the rewarded arm based on the landmarks present in between the arm ends. The animals begin the next trial in a new arm following a correct (rewarded) or incorrect (not rewarded) arm entry.
• Probe Trials: Probe trials may be performed to assess successful learning of the Star Maze task. Probe trial sessions include learning trials and test trials performed using the same pattern of landmark placement. In the learning trials of the 4 possible start points, only one or two of the arms are selected. The animals begin the trials in the selected start arm and learn to navigate towards the rewarded arm. Once the learning trials are completed, the start point is changed to one of the two previously unused arms, and the ability of the animal to navigate to the rewarded arm is observed.

The observed parameters and recorded data vary with the investigatory aims. In general, behavioral measures can include the following,

• Latency to initiate the task
• First choice
• Percentage of correct choices
• Percentage of incorrect choices
• Navigation accuracy
• Time spent in the correct zone
• Time spent in the incorrect zone
• Distance traveled
• Trial duration
• Frequency of backtracking
• Navigation strategy used

Based on the requirements of the investigation, EEG data may also be recorded. Other measures (relevant to the investigation) may include assessment of stress, anxiety, and heart rate levels, among others. Ancillary observations such as eye-tracking may also be recorded.