NEURONS IN THE CROW NCL ACCUMULATE EVIDENCE DURING RAPID DECISION-MAKING

Perceptual decision-making relies on the integration of sensory evidence to guide behavior. This process has been extensively studied in primates, revealing neuronal dynamics consistent with bounded evidence accumulation. However, it remains unclear how such computations are implemented in vertebrate brains with neural architectures distinct from mammals, such as birds, which lack a layered neocortex. Here, we used a comparative approach to investigate the neural basis of perceptual decision-making in carrion crows (Corvus corone) performing a random-dot motion discrimination task. The crows’ decision behavior was well captured by an evidence accumulation model, while they exhibited exceptionally short reaction times, suggesting rapid sensory processing and decision formation. Single-unit recordings from the nidopallium caudolaterale (NCL), an associative region of the avian telencephalon, revealed neurons selective for choice direction. Critically, neuronal activity predicted the crows’ choices across correct, error, and random-motion trials prior to response execution. Neuronal firing rates scaled with sensory evidence strength and reached a consistent activity level at response initiation, paralleling canonical neural correlates of decision-making. Together, these results highlight the central role of the NCL in sensory evidence integration and demonstrate that core computational principles of perceptual decision-making are conserved across distantly related vertebrate species.