In a virtual reality environment, the behavior of the computer-controlled virtual vehicle may be made more human-like by increasing the AI driver's reaction time to environmental stimuli, such as physical stimuli (e.g., detecting a loss of tire traction, audio warning signals, smoke, virtual fatigue, weather changes, etc.) or "visual" stimuli (e.g., virtual visual detection by the computer driver of a turn or obstacle in its path, ambient lighting differences, etc.). Reaction time may be increased by introducing a delay in receipt of stimuli by the artificial intelligence motion control system, by introducing a delay in receipt of control signals by the physics engine, or by modifying the control signal to degrade their accuracy in approximating a prescribed racing line.