Dogs are able to process basic numbers without training by using a part of their brains that corresponds very closely to the numerically responsive neural regions of humans.
Dogs process numerical quantities using a part of their brain similar to that used by humans for such a task. In addition, dogs do not need to be trained to do so. These are the conclusions reached by a study conducted at Emory University (United States) and led by Professor of Psychology Gregory Berns.
Stella Lourenco, associate professor of psychology at Emory and co-author of the study, has emphasized how important it is to understand neural mechanisms, both in humans and other species in order to understand better how our brains evolved over time and how they function now. In addition, this knowledge could help in the future to treat atypical features in the brain, and improve artificial intelligence systems.
Understanding neural mechanisms
The study included 11 dogs of different breeds who had their brains scanned while viewing variable numbers of illuminated dots on a screen. The results of the functional magnetic resonance imaging (fMRI) showed how the parietotemporal cortex of the dogs responded when the number of dots changed.
The parietotemporal cortex of eight dogs was activated to a greater extent when the number of dots was changing. According to the study, a number-sensitive region of the cortex exhibited greater activation when the numerical values of the dots were more dissimilar (2 vs. 10 dots) than when numerical values were constant (6 vs. 6 dots).
Number sense in animals
Researchers have associated the dogs' brain response to the number of dots with the ability to quickly estimate a number of objects in a scene, such as the number of predators approaching or the amount of food available to them. Evidence suggests that humans primarily rely on the parietal cortex for this ability, which is active even during childhood.
This basic awareness to numerical information is known as numerosity and is not based on training or thought. Scientists believe that it is a widespread characteristic among animals.
However, previous studies on primates have been mostly focused on subjects who had been previously trained. In this regard, certain neurons in the parietal cortex of monkeys were found to respond to numerical quantities. What was not concluded is whether this was due to numerosity or training, as primates went through many tests and were rewarded when they selected images with more points.
How did mathematical skills evolve in humans?
Humans and dogs are separated by 80 million years of evolution, the results of the current study provide some of the strongest evidence yet that numerosity is a shared neural mechanism that goes back at least that far, Berns says.
Part of the reason humans are able to do calculus and algebra is because they have this fundamental ability of numerosity that they share with other animals. The results of the current study pave the way to better understand how higher math skills evolved and how these skills develop over time in individuals, starting with basic numbering in childhood.