How intelligent were the Vikings

Are dogs smarter than cats? Science has an answer

Long discussed, there seems to be an answer to this eternal dispute.

It found that dogs have about twice as many neurons in their cerebral cortex as cats. This suggests that they are also about twice as intelligent.

This finding was in the scientific journal Frontiers in Neuroanatomy released. A team of scientists from six different universities in the USA, Brazil, Denmark and South Africa contributed to the research.

One of the authors of the study is the renowned neurologist Suzana Herculano-Houzel. The professor currently teaches at Vanderbilt University and has been studying the cognitive functioning of human and animal brains for ten years. In order to achieve the most accurate measurement possible, she begins by counting neurons, a specific type of nerve in the brain that is used to transport messages.

“You take the brain and turn it into soup,” she says soberly about the first step in the search for these neurons. She goes on to explain that this is how you get a number of isolated nuclei from neuronal cells. These allow scientists to estimate the number of neurons present.

WHY NEURONS JUST?

"Neurons are the basis of all units that convey information," says Herculano-Houzel. "The more units you find in the brain, the more cognitive abilities an animal has."

The research team only uses part of the brain to produce their high-yield “brain soup”, as she calls it. This folded, outer layer that sits on top of the other parts of the brain is called the cerebral cortex. Different parts of the brain process environmental stimuli such as seeing and feeling. In addition to other functions, the cerebral cortex composes these stimuli in order to make decisions and solve problems.

“The cerebral cortex is the part of the brain that enables complexity and flexibility,” says Herculano-Houzel.

To get an idea of ​​how many neurons dogs and cats have on average, the scientists used three different brains: one from a cat, one from a golden retriever, and one from a small mixed breed dog. Two canine brains were used because the size differences can vary significantly within the species.

In spite of their different sizes, the researchers found a good 500 million neurons in the two dog brains. That's more than double the 250 million found in the cat's brain.