You know how it seems your dog can tell if you give him three biscuits instead of four, or whether you followed the usual ritual for putting out a certain number of toys after he completes a trick? Researchers have just shown that he definitely can tell if these numbers change — and where in the brain he makes the computations.
Investigators at Emory University had dogs of varying breeds undergo magnetic resonance imaging (MRI) while showing them screens with different numbers of dots. In just about all the dogs, the parietotemporal cortex — behind the brain’s frontal lobe — reacted differently when the total dots in two different arrays was the same rather than different.
Being able to recognize different quantities without being taught is critical for a species to thrive. The scientists posit that from an evolutionary point of view, it is important for dogs to be able to quantify such things as, say, the number of predators approaching or the number of pieces of food available. Humans — and monkeys, fish, and bees, among other species — are born with the same ability.
