Neuromuscular Effects of Shifting the Focus of Attention in a Simple Force Production Task

ABSTRACT

Research on the focus of attention has begun exploring the physiological changes that underlie the difference between internal and external foci of attention. However, previous electromyography studies have used dynamic tasks, making it difficult to interpret electrophysiological data. The authors analyzed how the focus of attention affects a subject's ability to perform an isometric force production task (focus was directed either at the force platform or the muscles responsible for force production). Subjects received practice without attentional focus instructions and then completed blocks of trials with an external and internal attentional focus separately. An external focus led to significantly less error overall and reduced surface electromyography activity with lower median power frequencies in the antagonist muscle, but attentional focus had no effects on the agonist muscle. Thus, an external focus of attention led to more efficient motor unit recruitment patterns (reduced cocontraction) and improved performance. Posttest surveys revealed subjects were aware of their improved performance with an external focus.

Keywords:

• force production
• focus of attention
• motor control

ACKNOWLEDGMENTS

This work was supported in part by Army Research Office Grant W911NF-05–1-0153 to the University of Colorado. The authors would like to thank Matt Jones and Lyle Bourne for insightful comments and thoughtful discussion about this research.