Target selection for saccadic eye movements: prelude activity in the superior colliculus during a...

Area of Science:

• Neuroscience
• Oculomotor control
• Decision-making

Background:

• The superior colliculus (SC) is crucial for sensorimotor transformations, including eye movements.
• Understanding SC's role in target selection during complex tasks is essential.

Purpose of the Study:

• Investigate the superior colliculus's function in saccade target selection.
• Determine how task difficulty influences SC activity during decision-making.

Main Methods:

• Macaque monkeys performed a direction-discrimination task with varying motion signal strength.
• Recorded neural activity in the intermediate and deep layers of the SC.
• Analyzed target-specific predictive activity and its relation to motion strength.

Main Results:

• ~30% of SC neurons showed predictive activity for saccade targets before movement execution.
• Predictive activity intensity correlated with motion signal strength, indicating influence of task difficulty.
• Neural activity dependence on motion strength was independent of saccade metrics.

Conclusions:

• A subset of SC neurons exhibits predictive activity reflecting both target choice and task difficulty.
• These findings support the involvement of a specific SC network in saccade target selection.
• SC neural activity dynamically encodes decision-making processes during oculomotor tasks.