Can you rub your stomach and pat your head at the same time? How about drawing a circle with one hand and a square with the other?
According to a new study, the problem may be all in your head.
"The results of the study strongly suggest the source of the problem is that you can't think of more than one action at the same time. It's mental, not physical," said David Rosenbaum, professor of psychology and director of Penn State's Laboratory for Cognition and Action.
"Before we did our study, no one knew humans were physically capable of multi-tasking with their hands," he added.
Rosenbaum, along with Amanda Dawson, a recent Ph.D. recipient from Penn State, and John Challis, a Penn State associate professor of kinesiology, set up an experiment in which participants could track moving objects with light touch but without concentration.
The participants, who kept their eyes closed, tried to keep their hands in contact with two moving disks controlled by magnets on the other side of an opaque pane of glass.
The participants could easily trace the paths of the disks even in ways that are normally very difficult, such as tracing a circle with one hand and a square with the other, according to a press release.
"Using touch provides a very automatic way of making the hands move," Rosenbaum said.
But the study is not only applicable to simple coordination games. The findings can also help people who have lost movement ability to regain it, Rosenbaum said.
"This [study] might provide new methods to help people with movement problems using haptics," he said.
Haptics is the study of touch in general.
"Someone recovering from a stroke could use this to relearn and re-establish movement patterns," Challis said.
The study provides the strongest evidence up to this point in time that the reason most people are unable to voluntarily multi-task with their hands is that their minds get in the way of their bodies, according to the press release.
The findings appear in the November/December issue of the Journal of Experimental Psychology.
