For people unable to simultaneously rub their stomach while patting their head, a new twist may be at hand. Touch, rather than concentration, could let people multi-task with their hands, and this may also potentially help improve the performance of people with coordination problems, according to Penn State psychologists. "Most normal people cannot simultaneously draw a circle with one hand and a square with the other," says David Rosenbaum, distinguished professor of psychology and director of Penn State's Laboratory For Cognition and Action. "It is a fundamental limitation that the nervous system seems to impose on the hands for reasons that are not fully understood."