Neural correlates of innate preference for upward motion.

The ability to detect animate objects is a fundamental property of the animal visual system. Among the cues used to infer animacy, motion against gravity is particularly salient, as upward movement signals self-propelled, living objects. While humans and newly hatched domestic chicks show spontaneous attention to upward-moving stimuli, the neural mechanisms underlying this innate preference remain unknown. Here, we show that neurons in the nidopallium of 1-week-old domestic chicks encode upward, animacy-suggestive motion. Using extracellular recordings alongside video- and accelerometer-based behavioral tracking, we found a robust orienting response toward upward-moving stimuli. Most direction-sensitive neurons in the nidopallium responded preferentially to upward motion, and the population activity of these neurons accurately predicted the chicks' spontaneous behavioral responses. These findings reveal a direct link between sensory encoding and innate behavioral preference, providing insight into the neural basis of sensitivity to upward, animacy-related motion cues.