Somewhere in a laboratory at the University of Tübingen, two carrion crows watched drifting dots and chose a side in roughly a quarter of a second, a pace that outstrips the humans and monkeys who have long served as our measures of quick perception. The finding reaches into an old question about how minds weigh what they see and turn it into action, suggesting that the logic of decision-making may be shared across very different brain designs. Yet the reason behind the birds' speed remains a open question, and the evidence rests on just two animals, so the story is one of promising glimpses r
Carrion Crows Decide Visual Motion Twice as Fast as Humans and Monkeys, Study Finds
Seventy milliseconds in, the crow's neurons had already begun to split left from right
Mark
What's the core result here? Crows are just faster?
Mimi
Faster, and not sloppy about it. Two carrion crows averaged 235 milliseconds to say which way dots were moving, and with clear motion they were nearly 100 percent accurate.
Mark
And the brain recordings add what?
Mimi
They show when the decision begins. About 70 milliseconds after the dots appeared, neurons in the nidopallium caudolaterale were already separating left from right, well before the peck.
Luke
Before we get carried away, the sample is two birds. The twice-as-fast comparison to humans and monkeys is the researchers' claim, and the report doesn't say how those comparison figures were gathered.
Mark
Fair. Does the similarity to primate decision-making hold up?
Mimi
Per Nieder, the neural activity fits established models: it builds up to a threshold, and it reflects both how clear the motion is and which choice the bird makes. That's striking because bird brains lack a layered cortex.
Luke
Fitting a model isn't the same as proving identical mechanisms, though. And the evolutionary explanation, flight and beak-guided foraging, is a suggestion. Nothing in the reporting tests it.
Mark
So what's actually unknown?
Luke
Why the crows are faster. The mechanism is unexplained, and the researchers themselves say more studies are needed.
Mimi
That gap is the next piece of work: how a differently built brain gets to a similar decision so much sooner.
Il Polso
- Two crows pecked the correct side of a moving-dot display in an average of 235 milliseconds, roughly twice the speed of humans and monkeys on the same kind of task.
- Speed did not cost accuracy: the birds approached perfect choices on clear signals and still beat random guessing on hard ones.
- Neurons in the crow's nidopallium caudolaterale split apart by about 70 milliseconds, well before any movement, and climbed steadily toward a decision threshold.
- The same decision pattern seen in primates appears in a bird brain with no layered cerebral cortex, a result that challenges assumptions about what architecture is required.
- Researchers suspect flight and beak-guided foraging shaped this speed, but the biological mechanism is still unknown and more studies are needed, starting from a sample of only two birds.
Somewhere in a laboratory at the University of Tübingen, two carrion crows watched drifting dots and chose a side in roughly a quarter of a second, a pace that outstrips the humans and monkeys who have long served as our measures of quick perception. The finding reaches into an old question about how minds weigh what they see and turn it into action, suggesting that the logic of decision-making may be shared across very different brain designs. Yet the reason behind the birds' speed remains a open question, and the evidence rests on just two animals, so the story is one of promising glimpses rather than settled understanding.
Two carrion crows sat before a touchscreen at the University of Tübingen and watched a field of dots drift across it. Their task was simple: decide whether most of the dots moved left or right, then peck the matching target. On average, they made the call in 235 milliseconds.
The study, published in the journal Science by Philipp Schmidbauer and Professor Andreas Nieder, reports that this is about twice as fast as humans and monkeys manage on comparable visual motion tasks. The speed did not come at the cost of accuracy. With clear signals the crows came close to perfect, and even on difficult displays their choices beat random guessing.
The team also recorded individual neurons in the nidopallium caudolaterale, a region involved in processing information and decision-making and often compared to the human prefrontal cortex. Roughly 70 milliseconds after the dots appeared, neurons linked to the two choices were already firing in distinct patterns, long before the bird moved. Their activity then rose steadily to a threshold associated with committing to a choice, tracking both the clarity of the motion and the direction the crow picked.
That rise to a threshold matches established models of decision-making in humans and other primates, which is what gives the result weight. Birds, however, lack a cerebral cortex organized into layers, so the same principles of weighing evidence appear to run on a very different physical architecture.
The researchers suggest a possible cause for the speed, though they stress it is a hypothesis. Birds rely on vision for rapid, precise flight and for guiding their beaks while foraging, and such demands may have shaped how quickly their brains turn sight into action. The mechanism itself remains unknown, and further studies will be needed. It is also worth keeping in mind that the experiments involved only two crows.
Two carrion crows sat in front of a touchscreen at the University of Tübingen and watched a field of dots drift across it. Their job was to decide whether most of the dots were moving left or right, then peck a target on the matching side. On average, they took 235 milliseconds to make the call.
That figure is the headline of a study published in the journal Science, by Philipp Schmidbauer and Professor Andreas Nieder of the university's Institute of Neurobiology. According to the researchers, it is about twice as fast as humans and monkeys manage on this kind of visual motion task. The speed did not come at the expense of accuracy. When the dots gave a clear signal, Schmidbauer reports, the crows reached nearly 100 percent accuracy. Even when the motion was hard to read, their choices were still better than random guessing.
The team also wanted to know what was happening inside the birds' heads while they decided. They recorded the activity of individual neurons in a region called the nidopallium caudolaterale, which plays a role in processing information and making decisions and is often compared to the prefrontal cortex in humans.
The recordings showed the decision process starting almost at once. Just 70 milliseconds after the dots appeared, neurons tied to the two possible choices were already firing in distinct patterns, well before the bird moved to peck. From there, neural activity climbed steadily until it hit a threshold associated with committing to a decision. The activity tracked two things: how clearly the dots signaled a direction, and which direction the crow ultimately chose.
That pattern is what makes the finding more than a curiosity about speed. A steady rise to a threshold is the signature of established models of decision-making in humans and non-human primates. Nieder said the findings show that neuronal dynamics in the avian brain are consistent with those models. Yet bird brains are built differently: unlike mammals, birds lack a cerebral cortex organized into layers. The same basic principles for weighing evidence appear to operate in a very different physical architecture, and in this task the crows ran the process twice as fast as primates.
The researchers offer a possible reason for the speed, though it is a suggestion rather than a demonstrated cause. Birds depend on vision for precise, rapid maneuvers in flight and for guiding their beaks to objects while foraging. Nieder noted exactly that, pointing to the demands of animals that fly and use their beaks to interact with the world. Such pressures may have shaped how quickly their brains turn what they see into action.
What remains unanswered is the mechanism. The exact biological basis of the crows' speed advantage is still unknown, and the researchers say further studies will be needed to explain how a differently structured brain can reach comparable visual decisions so much faster than those of humans and monkeys. It is also worth remembering the scale: the experiments involved two crows.
Citazioni salienti
Even when the patterns of motion were hard to recognize, the crows' decisions were still better than random choices, and with clear signals they reached nearly 100 percent accuracy.— Philipp Schmidbauer, University of Tübingen
Neuronal dynamics in the avian brain are consistent with established models of decision-making in humans and non-human primates.— Andreas Nieder, University of Tübingen
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