A group of neuroscientists from the Universities of Lethbridge and Alberta, both in Canada, has identified a neural circuit that may underlay intelligence in parrots.
Gutiérrez-Ibáñez et al found that SpM is greatly enlarged in parrots. Image credit: Edmond Lafoto.
“An area of the brain that plays a major role in primate intelligence is called the pontine nuclei. This structure transfers information between the two largest areas of the brain, the cortex and cerebellum, which allows for higher-order processing and more sophisticated behavior,” said lead author Dr. Cristian Gutierrez-Ibanez, from the University of Alberta.
“In humans and primates, the pontine nuclei are large compared to other mammals. This makes sense given our cognitive abilities.”
Birds have very small pontine nuclei. Instead, they have a similar structure called the medial spiriform nucleus (SpM) that has similar connectivity.
Located in a different part of the brain, SpM does the same thing as the pontine nuclei, circulating information between the cortex and the cerebellum.
“This loop between the cortex and the cerebellum is important for the planning and execution of sophisticated behaviors,” said co-author Professor Doug Wylie, also from the University of Alberta.
In the study, the researchers studied the brains of birds, comparing the relative size of the SpM to the rest of the brain.
They used samples from 98 birds from the largest collection of bird brains in the world, including everything from chickens and waterfowl to parrots and owls.
They determined that parrots have a SpM that is much larger than that of other birds.
“The SpM is very large in parrots. It’s actually two to five times larger in parrots than in other birds, like chickens,” Gutierrez said.
“Independently, parrots have evolved an enlarged area that connects the cortex and the cerebellum, similar to primates. This is another fascinating example of convergence between parrots and primates.”
“It starts with sophisticated behaviors, like tool use and self-awareness, and can also be seen in the brain. The more we look at the brains, the more similarities we see.”
The research is published in the journal Scientific Reports.
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Cristián Gutiérrez-Ibáñez et al. 2018. Parrots have evolved a primate-like telencephalic-midbrain-cerebellar circuit. Scientific Reports 8, article number: 9960; doi: 10.1038/s41598-018-28301-4
