Triggering mechanisms in microsaccade and saccade generation: a novel proposal

Area of Science:

• Neuroscience
• Ophthalmology
• Systems Neuroscience

Background:

• Saccades are rapid eye movements essential for changing gaze.
• Microsaccades are small, frequent saccades interrupting fixation.
• The neural control of saccades is known, but microsaccade triggers remain unclear.

Purpose of the Study:

• To review evidence linking saccade and microsaccade generation.
• To discuss existing models of microsaccade production.
• To propose a novel neural mechanism for triggering saccades and microsaccades.

Main Methods:

• Literature review of saccade and microsaccade generation.
• Analysis of neural pathways involved in eye movements.
• Theoretical modeling of neural circuits controlling saccades and microsaccades.

Main Results:

• Evidence suggests saccades and microsaccades share common neural pathways.
• Current models of microsaccade generation are discussed.
• A new model proposes reciprocal inhibition between omnipause and long-lead burst neurons triggers eye movements.

Conclusions:

• The proposed model suggests eye movements are triggered when long-lead burst neuron activity overcomes omnipause neuron inhibition.
• This mechanism does not rely on superior colliculus activity surpassing a threshold.
• This offers a new perspective on the neural basis of saccadic and microsaccadic eye movements.