"Set shifting occurs when you've learned to pay attention to one thing and then need to concentrate on something different," he said. "For instance, I could ask you to name the suit on playing cards as I turn them over, and then I'd ask you to tell me the numbers on the next cards I turn over.
"But you might fail to tell me the numbers because you are continuing to pay attention to the previous set - the card suits. You've both learned to pay attention to the suits and that the numbers are irrelevant so you should ignore them."
Mice compose the majority of medical research animals, but since no test existed to monitor them for such skills as set shifting, their usefulness in studying autism, other similar diseases and traumatic brain injuries was limited, Garner said.
The Garner team's mice were tested in a maze with rewards of one-quarter of a piece of sweetened cereal hidden in two-inch diameter metal bowls. The scientists varied the material inside the bowls where the cereal piece was hidden and also varied the outer texture and smell of the bowls.
The rodents learned to find the cereal by using a cue such as the bowl's outer texture. After experience solving a number of tasks with this cue, the animals were given a new cue for finding the cereal, such as the bowl's smell.
"Like people performing a series of similar tasks over and over and then having to change their focus to a new problem, the mice continued to look for the bowl with the same outer texture to find the cereal," Garner said. "The more times they had used the bowl texture as a cue, the more difficult it was for the animals to change to the new food-finding cue."
Almost all people have a little difficulty set-shifting in a task like this, he said. However c