A grasping mechanism that has been attributed primarily to early development in babies and toddlers may be at work in old age as well, researchers at the Ben-Gurion University of the Negev say.
In early development, babies make what might seem like random, exaggerated movements in all directions, until they learn to purposefully reach for objects. Their movement is very variable, until they find a way to achieve their goals, for example reaching for a Cheerio and putting it into their mouth. The mechanism is called exploration-exploitation. They explore the range of possibilities, and when they find a good movement plan, they exploit it.
In an article published Monday in Scientific Reports, part of the Nature group, Dr. Shelly Levy-Tzedek, head of the Cognition, Aging and Rehabilitation Lab in the Dept. of Physical Therapy, Faculty of Health Sciences, ABC Robotics and The Zlotowski Center for Neuroscience at BGU, and her team showed that older adults use this same exploration-exploitation mechanism and perform tasks by increasing the speed and the amplitude of their movements in the absence of visual feedback. Not only that, older adults were also able to learn to use this increased movement to benefit future movements, the researchers said.
In their experiment, the older adults were making movements in an effort to stay on target, but were not very successful.
“Their movements were too slow and too small. We then induced them to make movements that were larger and faster, and their performance on the original task improved significantly,” says Levy-Tzedek.
While they have not tested this new mechanism in a physical therapy context yet, it holds promise, Levy-Tzedek said.
“Perhaps getting older adults to make exaggerated movements can help fine-tune their performance on specific tasks that they find difficult to perform otherwise,” she says.
The researchers found that making “mistakes” actually helps improve future task performance. They also discovered that once a better movement pattern was established, the variability of movement dropped, leading them to the conclusion that variability plays a role in finding a more successful movement plan.
The study was funded by the Brandies Leir & Bronfman Foundations; the Promobilia Foundation; the Israeli Science Foundation; and the Helmsley Charitable Trust through the Agricultural, Biological and Cognitive Robotics Center of Ben-Gurion University of the Negev.