Ask even the youngest schoolchild how many senses we have and she’ll tell you five: sight, sound, smell, taste, and touch.
Neuroscientist Don Katz thinks this might be wrong. The correct answer, he says, will most likely turn out to be one.
For nearly a decade, Katz, an associate professor of psychology at Brandeis University, has been investigating the interconnection of smell and taste in rats. In 2009, he showed that when rats lose their ability to taste, it alters their sense of smell. Two years later, he published a paper suggesting that rats depend on smell as much as taste to determine what food they like.