"Where Would You Stimulate?" Beliefs About Anatomical Relevance for Enhancing Motor Performance With Non-Invasive...

While non-invasive electrical stimulation is used clinically to enhance motor performance, its efficacy and mechanisms remain unclear. Studies show that personal factors, such as beliefs and expectations of stimulation, can impact how much a person benefits from the stimulation itself. Furthermore, beliefs related to the "closeness is strength of effect" have been observed outside of electrical stimulation contexts, suggesting that the location of stimulation (eg, head and neck) for improving motor performance may impact how much they believe the stimulation will work. This exploratory study investigated beliefs about the optimal target region of stimulation for maximizing the effect of stimulation itself.

Eighty participants (39 females; 46.9 ± 12.6 years) completed an online spatial mapping task in which they were asked to indicate where they would place the electrodes for electrical stimulation to hypothetically enhance specific functions: "hand movement," "arm movement," "leg movement," and "attention/concentration." Participants selected their placement by clicking a blank human figure in anatomical position. Information about prior use/knowledge of non-invasive stimulation was also collected.

Optimal target region of stimulation was significantly associated with the body movement/function to be enhanced (P < .001). This association was independent of prior non-invasive stimulation knowledge (P = .242) and sex (P = .923).

These findings suggest a pre-existing belief of spatial proximity for electrical stimulation in which placing electrodes closer to the body region of interest would maximize improvement hypothetically.