Microsaccades and blinks trigger illusory rotation in the "rotating snakes" illusion

Area of Science:

• Visual neuroscience
• Oculomotor function
• Perception

Background:

• The Rotating Snakes Illusion, a form of illusory motion, is well-known but its underlying mechanisms are debated.
• Previous research suggested slow ocular drift drives the illusion, while microsaccades do not.

Purpose of the Study:

• To investigate the precise role of eye movements in triggering the Rotating Snakes Illusion.
• To determine whether transient oculomotor events or continuous drift are responsible for the illusory motion.

Main Methods:

• High-precision eye movement recording during observation of the Rotating Snakes Illusion.
• Subjective reports of perceived rotation were correlated with recorded eye movement data.

Main Results:

• A significant quantitative correlation was found between microsaccade and blink occurrence and the perception of illusory rotation.
• Illusory motion perception was strongly linked to transient oculomotor events.

Conclusions:

• Transient oculomotor events, including microsaccades, saccades, and blinks, are key triggers for the Rotating Snakes Illusion.
• Continuous ocular drift is unlikely to be the primary driver of this visual illusion.