Ultrarapid decision-making in an avian brain.

Perceptual decision-making is well studied in mammals, but its operation in other vertebrates remains unclear. We show that carrion crows (Corvus corone) make deliberate decisions in a classic visual motion discrimination task with unprecedented speed, reporting choices in approximately 235 milliseconds on average, which is roughly twice as fast as has been observed in monkeys or humans and without sacrificing accuracy. Recordings from the pallial endbrain reveal that direction-selective neurons encode the upcoming choice as early as about 70 milliseconds after stimulus onset and about 170 milliseconds before the response, with ramping activity scaling with sensory evidence and converging at response onset. These findings highlight the extraordinary efficiency of avian decision-making circuitry, possibly shaped by evolutionary pressures for rapid visuomotor control.