Visuomotor processing in the superior colliculus

The superior colliculus (SC) is an evolutionarily conserved midbrain structure that maintains a consistent laminar organization across most mammalian species. This architecture reflects shared functional requirements for visual processing, attentional control, and motor coordination. Physiological studies confirm that the SC can process visual information independently of the primary visual cortex (V1), sustaining visuomotor behaviors through subcortical networks following V1 lesion or inactivation. This capacity illustrates how alternative neural pathways can maintain essential survival-related functions without cortical involvement. Comparative approaches reveal both conserved operational principles and species-specific adaptations. In rodents, SC activity guides attentional allocation, perceptual selection, and adaptive decision-making based on visual cues. In primates, its extensive connectivity with cortical and subcortical structures supports target selection, saccade generation, and sensorimotor integration. Collectively, these findings establish the SC as a fundamental substrate for adaptive signal processing that links perception with action across diverse behavioral contexts. This review synthesizes current understanding of the mammalian SC, focusing on its roles in visual processing, attention, and motor coordination. By synthesizing evidence across species, we describe how conserved neural architecture contributes to adaptive perception and behavior, and how the SC complements cortical pathways in shaping visually guided actions.