Non-linear retinal processing supports invariance during fixational eye movements

• Fixational eye movements produce erroneous motion signals.
• We present a model mechanism to correct for these errors.
• The model relies on the non-linear spatial response of parasol ganglion cells.
• This model does not require extra-retinal information.
• Two well known illusions can be explained as errors of the correction mechanism.

Fixational eye movements can rapidly shift the retinal image, but typically remain unnoticed. We identify and simulate a model mechanism for the suppression of erroneous motion signals under fixational eye movements. This mechanism exploits the non-linearities common to many classes of large retinal ganglion cells in the mammalian retina, and negates the need for extra-retinal signals or explicit gaze information. When tested using natural images undergoing simulated fixational eye movements, our model successfully distinguishes “real world” motion from retinal motion induced by eye movements. In addition, this model suggests a possible explanation for several fixational eye movement related visual illusions such as the Ouchi–Spillmann and “Out-of-focus” illusions.