CONTRIBUTIONS OF SUPERIOR COLLICULUS AND PRIMARY VISUAL CORTEX TO VISUAL SPATIAL DETECTION IN FREELY MOVING MICE

Visual spatial detection is an early step in visual processing for selecting appropriate actions and making decisions. Previous studies in head-fixed mice have shown that both the superior colliculus (SC) and the primary visual cortex (V1) contribute to visual detection. However, the neural mechanisms underlying visual spatial detection in freely moving animals remain poorly understood, due to the difficulty of controlling visual stimuli while simultaneously tracking eye and head movements. To overcome these challenges, we developed an integrated system that combines closed-loop presentation of visual stimuli, neural recordings, optogenetic perturbations, and simultaneous eye and head position tracking. Using this approach, we found that SC activity is more predictive of reaction time than V1. In addition, SC neurons exhibit more sustained activity than V1 neurons during visual spatial detection. Optogenetic inactivation of either SC or V1 revealed that SC inactivation caused a more pronounced deficit in visual detection compared to V1. Together, these results demonstrate that SC and V1 exhibit distinct neural dynamics and establish their relative causal contributions to visual spatial detection.