Researchers have found yet another way that humans and dogs are of one mind. This time, the subject of the similarity is how they process concepts of quantity—an important ability for many animals. Knowing roughly how many predators are approaching or how many food items are available for foraging has survival advantages. So, it is little wonder many animals have a basic sensitivity to quantity, and there is a term for it—numerosity.
To address canine numerosity, Lauren Aulet, a graduate student at Emory University working with Gregory Berns, used functional magnetic resonance imaging (fMRI) to study dogs’ brains while they viewed various quantities of dots. The area of the dot array was always the same, but the number of dots within it varied. The dogs in the study have been trained to sit still during the fMRI. They passively watched various groups of dots as they were flashed on a screen.
The parietotemporal cortex in the dogs responded to variation in the quantity of dots in the arrays. That result shows that dogs and humans use a similar part of the brain to process the quantity of items they see. It also reveals that dogs don’t need to be trained to do it. That’s important because previous studies of dogs have involved training them to discriminate between different quantities of items.
Showing that dogs are able to tell the difference in the number of items spontaneously suggests that there is an evolutionary history of this ability across mammalian species. This research supports the idea that the neural mechanism associated with numerosity has a shared history extending back at least tens of millions of years.
Humans also use the parietotemporal cortex area of the brain for higher mathematical skills. Aulet is interested in the evolution of higher mathematical ability in humans from the shared mechanism of numerosity found in so many species. Studying its function in other species is one way to explore how advanced numerical abilities evolved from basic mechanisms for processing concepts of quantity.