Crows made rapid visual choices while keeping accuracy high
Two carrion crows in a University of Tübingen experiment identified the direction of moving dot patterns and signaled their choice in an average of 235 milliseconds, researchers reported. The work, published in Science, examined both the birds’ behavior and the neural activity associated with their decisions.
The result is notable because the task was not simply a reflex. The birds had to assess a visual display in which dots moved predominantly left or right, determine which direction was better supported by the available evidence, and then peck the corresponding target on a touchscreen to receive a reward.
Even when the motion pattern was difficult to distinguish, the crows made choices that were better than random, according to the researchers. When the visual signal was clear, their accuracy approached 100%.
Neural signals separated within 70 milliseconds
Philipp Schmidbauer and Andreas Nieder recorded neurons in the nidopallium caudolaterale, an associative area of the avian brain that the researchers compare functionally with the human prefrontal cortex. The measurements showed that neural signals associated with the two possible motion directions began to diverge as early as 70 milliseconds after the visual stimulus appeared.
That separation occurred well before the animals made their behavioral response. As a decision formed, neural activity increased until it reached a threshold, after which the crow pecked one of the two targets. The neural responses reflected both the selected direction and the strength of the visual information available to the bird.
In practical terms, the experiment gives researchers a view of the sequence between seeing a stimulus, accumulating evidence and committing to an action. It also indicates that this sequence can unfold extremely quickly in a brain organized very differently from a mammalian brain.
Different brains can support comparable decision dynamics
Crows do not have a neocortex like that of mammals. Yet the study found decision-related neural dynamics consistent with processes previously described in primates. The comparison does not mean the bird and mammal brains are anatomically the same. Rather, it suggests that different brain structures can support similar computations when an animal must turn uncertain sensory information into a choice.
The Tübingen team’s result adds to the case that birds can be powerful subjects for studying cognition. Here, the crows did not merely respond rapidly to an obvious cue. Their performance remained above chance when the evidence was ambiguous, and their brain activity changed in step with the quality and direction of that evidence.
The study therefore links an observable behavioral result—an average response time of 235 milliseconds—to a measurable neural process that starts much earlier. For researchers studying decision-making, that combination is valuable: it ties speed and accuracy to activity in a specific associative brain region.
Why the finding matters
Rapid, accurate decisions are essential whenever an animal must interpret a changing environment. The new experiments do not establish that crows think in the same way as humans or monkeys. They do show that crows can perform a demanding visual discrimination task at remarkable speed, with neural signatures that track the evolution of the decision.
That makes the work relevant beyond a comparison of reaction times. By observing how evidence-sensitive neural activity develops in the avian brain, researchers can test broader ideas about how nervous systems produce decisions. The study’s central lesson is that a distinct brain architecture can still generate fast, graded and highly accurate choices.
For the two carrion crows in the experiment, the test was a touchscreen display of moving dots. For neuroscience, it offers a compact model for examining the path from visual input to a committed action.
This article is based on reporting by Phys.org. Read the original article.
Originally published on phys.org
