Symbolic cue-driven activity in superior colliculus neurons in a peripheral visual choice task

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Oculomotor Research

Background:

• The superior colliculus (SC) is traditionally known for its role in controlling saccadic eye movements.
• Emerging evidence suggests the SC is also involved in higher cognitive functions like attention and target selection.

Purpose of the Study:

• To investigate whether the SC exhibits cognitive responses independent of direct visual stimulation.
• To determine if SC neurons can be activated by internally generated cognitive signals.
• To assess the role of the SC in learned associations between spatial location and arbitrary cues.

Main Methods:

• A visual choice response task was employed.
• Visuomotor neurons in the SC were recorded.
• A central symbolic cue, presented outside the neurons' visual response fields, was used to elicit cognitive activity.
• Activity was analyzed in relation to cue presentation and subsequent saccade initiation.

Main Results:

• SC neurons demonstrated activation by a symbolic cue presented outside their classical visual receptive fields.
• This activation pattern suggests that cognitive signals alone can drive SC cell activity.
• A significant portion of recorded SC cells accurately reflected cue-aligned target selection before saccade execution.

Conclusions:

• The study provides evidence that the superior colliculus is involved in cognitive processes beyond basic visuomotor control.
• Cognitive signals can independently activate SC neurons, challenging previous notions of purely stimulus-driven responses.
• These findings support the existence of internally generated signals within the SC, contributing to cognitive functions like attention and decision-making.