When you pour a cup of coffee, where do you direct your attention?
Most likely you focus on the lip of the carafe and the rim of the mug. Meanwhile, the biomechanics of pouring—the angle of your wrist, twist of your shoulder, and lift of your elbow—happen on autopilot. You probably don’t spend a single conscious thought about those motions, even though they have to be executed with precision to avoid a spill. You’re concentrating on external, not internal, factors.
The same principle can help amputees adapt more quickly and effectively to prosthetic limbs, according to new research from physical therapist Szu-Ping Lee. An associate professor at the University of Nevada at Las Vegas, Lee studied the training amputees receive as they learn to use a new device. He found that 64 percent of the verbal instructions provided by prosthetists, physical therapists, and other clinicians are focused internally on the movements of the patients’ body and/or prosthesis, rather than externally on the intended effects.
This approach can leave patients vulnerable to “self-invoking trigger” behaviors, which Lee describes as “frequent evaluation of one’s own movements associated with a task [that] negatively impacts task learning and performance.” In simpler terms: Hyperawareness often causes anxiety that interferes with good outcomes.
In contrast, Lee argues, “an external focus that removes the emphasis of controlling the complex coordination of body movements may activate the more natural ‘automatic’ processes of goal-action.” Instead of demanding vigilant control over every flex and twitch, externally focused instructions allow nerve pathways and muscle memory to evolve intuitively.
To illustrate the concept, Lee suggests that instead of giving internally focused instructions such as “take longer strides,” clinicians should place markings on the floor and instruct the patient to step on each mark. Such outcome-oriented directions would help patients improve their gait without obsessing over their bodies.
“While experimental research into the benefits of an external focus of attention during prosthetic skill training is pending,” Lee concludes, “evidence from other clinical models have shown that adopting an external focus can enhance motor performance and benefit long-term learning.”
Read the full paper at PLOS One.
