Crows Possess Higher Intelligence Long Thought a Primarily Human Attribute, New Research Shows

Research unveiled on Thursday in Science finds that crows know what they know and can ponder the content of their own minds, a manifestation of higher intelligence and analytical thought long believed the sole province of humans and a few other higher mammals. STAT reports: “Together, the two papers show that intelligence/consciousness are grounded in connectivity and activity patterns of neurons” in the most neuron-dense part of the bird brain, called the pallium, neurobiologist Suzana Herculano-Houzel of Vanderbilt University, who wrote an analysis of the studies for Science, told STAT. “Brains can appear diverse, and at the same time share profound similarities. The extent to which similar properties present themselves might be simply a matter of scale: how many neurons are available to work.”

The study shows that neurons in the most complex part of the crows’ brain, the pallium, “do have activity that represents not what was shown to them, but what they later report,” said Herculano-Houzel. Neurons “represent what the animals next report to have seen — whether or not that is what they were shown,” she said. The neurons figure this out, so to speak, during the time lapse between when Nieder tells the birds the rule and when they peck the target to indicate their answer. “That’s exactly what one would expect from neurons that participated in building the thoughts that we later report,” she said, suggesting that corvids “are as cognitively capable as monkeys and even great apes.” A second study, also in Science, looked in unprecedented detail at the neuroanatomy of pigeons and barn owls, finding hints to the basis of their intelligence that likely applies to corvids’, too. STAT reports: Specifically, the pigeons’ and owls’ neurons meet at right angles, forming computational circuits organized in columns. “The avian version of this connectivity blueprint could conceivably generate computational properties reminiscent of the [mammalian] neocortex,” they write. “[S]imilar microcircuits … achieve largely identical cognitive outcomes from seemingly vastly different forebrains.” That is, evolution invented connected, circuit-laden brain structure at least twice. “In theory, any brain that has a large number of neurons connected into associative circuitry … could be expected to add flexibility and complexity to behavior,” said Herculano-Houzel. “That is my favorite operational definition of intelligence: behavioral flexibility.” That enables pigeons to home, count, and be as trainable as monkeys. But for sheer smarts we’re still in the corvid camp.

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