Birds’ compact nervous system seems to help them handle tasks very quickly.
Much of what we know about how a brain makes decisions comes from studying monkeys watching dots. In a task known as a random-dot-motion task, a cloud of flickering specks drifts weakly in one direction while the subject tries to determine whether—and in which direction— it’s moving. The task has shown that in the primate neocortex, neurons gather visual evidence over time, with their firing rates climbing until they cross a threshold, when the animal commits to a decision.
But avian brains don’t have a neocortex, so it wasn’t obvious how they made similar decisions.
“This was the big question,” said Andreas Nieder, a neurobiologist at the University of Tübingen. “How [would] a differently organized avian brain encode decisions?”
To find out, Nieder and his colleague Philipp Schmidbauer put two carrion crows through the same task the monkeys faced, recording their brain activity along the way.…