Microsaccades Do Not Give Rise to a Conscious Feeling of Agency for Their Sensorimotor Consequences in Visual...

Area of Science:

• Neuroscience
• Perception
• Motor Control

Background:

• The feeling of agency (FoA) is the sense of controlling one's actions and their outcomes.
• FoA has been extensively studied for bodily movements, but its presence in eye movements, specifically microsaccades, remains unclear.

Purpose of the Study:

• To investigate whether microsaccades are characterized by FoA.
• To determine if intention plays a role in mediating FoA for microsaccades.

Main Methods:

• Participants performed tasks involving microsaccades (intended and unintended) while viewing a stimulus whose visibility depended on eye movements (active condition) or was independent (replay condition).
• Intentional binding was used to measure FoA by assessing the perceived timing between an action (microsaccade) and its sensory consequence.
• Two experiments were conducted, varying instructions for saccade generation to examine intended, unintended, and spontaneous microsaccades.

Main Results:

• Microsaccades, whether actively generated or replayed, consistently increased stimulus visibility when aligned with stimulus motion.
• No significant difference in temporal estimates was found between the active and replay conditions for any microsaccade type.
• This indicates the absence of temporal binding between eye movements and sensory consequences, and that intention does not facilitate FoA for microsaccades.

Conclusions:

• The findings do not support the presence of FoA for microsaccades.
• Intention is insufficient to elicit FoA for minuscule motor acts like microsaccades.
• Further research is needed to explore FoA in larger saccadic eye movements.