Saccadic Corollary Discharge Underlies Stable Visual Perception.

Area of Science:

• Neuroscience
• Vision Science
• Perception

Background:

• Saccadic eye movements cause retinal image displacement, yet visual perception remains stable.
• A proposed mechanism for visual stability is the corollary discharge (CD), a neural signal mirroring eye movement commands.
• The CD circuit's role in visual perception remains under investigation.

Purpose of the Study:

• To investigate the influence of the CD circuit on visual perception.
• To determine if the CD signal is essential for maintaining visual stability during saccades.

Main Methods:

• Macaque monkeys were trained to report perceived eye direction.
• The corollary discharge (CD) pathway was reversibly inactivated in the thalamus.
• Perceived eye direction was compared to actual eye position during CD inactivation.

Main Results:

• Inactivating the CD circuit decoupled perceived eye direction from actual eye position.
• The perceived eye direction was not influenced by proprioceptive or contextual visual cues.
• This demonstrates that the CD signal is critical for accurate perception of eye position.

Conclusions:

• The corollary discharge (CD) provides crucial internal information for perceived visual stability.
• The CD signal may serve as an internal saccade vector, integrating disparate retinal images.
• This finding supports the hypothesis that CD is fundamental to maintaining a stable visual world.