Why does a visual frame of reference affect whether an object appears to move?

A visual frame of reference is essential for accurate perception because the human visual system relies on the surrounding environment to establish a stable context for motion. When we lack a clear, stationary background, our brain struggles to distinguish between the movement of an object and the movement of the observer or their eyes.1

This reliance on a frame of reference leads to several phenomena:

• Induced Movement: We have a natural tendency to perceive the larger, surrounding environment as a stable frame. If a small object is presented within a moving frame, we often falsely attribute the motion to the object itself rather than the frame.1
• Relative Motion: In the absence of a stable framework, such as an isolated point of light in a dark room, we may experience autokinetic movement, where a stationary object appears to drift due to the instability of our own eye position.1
• Visual Stability: Our brain uses motor-nerve signals to differentiate between voluntary eye movements and actual movement in the scene. If these signals are absent or mismatched—such as when the eye is moved passively—the brain may incorrectly perceive the scene as moving.2

Ultimately, the brain interprets motion by comparing retinal changes against these internal and external frames of reference.12