Immediate Effect of Visual Attention on Corticospinal Excitability in the Upper Trapezius Muscle

Abstract

This study investigated the immediate effect of visual attention on corticospinal excitability in the upper trapezius muscle. 10 healthy males gazed at a horizontal bar. A warning tone, indicating that a line would be slightly displaced 7,400 msec. later, was delivered in the high-attention-demand condition. A different warning tone, indicating the line would not be displaced, was delivered in the low-attention-demand condition. Participants verbally declared the direction of line displacement in the high-attention-demand condition, or stated that the warning tone meant that the line would not be displaced in the low-attention-demand condition. The amplitude of the motor-evoked potential in the upper trapezius muscle increased 7,000 msec. after the warning tone in the high-attention-demand condition. Apparently, visual attention immediately increases corticospinal excitability in the upper trapezius muscle.