Crows can evaluate visual information twice as fast as mammals, according to research that challenges long-standing assumptions about avian cognition. The finding resolves a significant gap in neuroscience. The lack of a neocortex in bird brains had made the mechanism for decision-making unclear.
Traditional models of brain decision-making rely heavily on studies of primates performing random-dot-motion tasks. In these experiments, a subject observes a cloud of flickering specks drifting weakly in one direction. The subject must determine the trajectory. In the primate neocortex, neurons accumulate visual evidence over time. Their firing rates rise until they cross a specific threshold, triggering a committed decision. Because avian brains lack this neocortical structure, it was previously not obvious how birds encoded similar decisions.
Andreas Nieder, a neurobiologist at the University of Tübingen, identified this structural difference as the central question for researchers. He noted that understanding how a differently organized avian brain encodes decisions was a major hurdle in the field. The new evidence indicates that despite this fundamental anatomical difference, crows perform these evaluations with significantly greater speed than their mammalian counterparts.