Scientists Discover How the "Viewing Angle" in Imagination Affects Muscle Signal Strength

Imagining oneself from an external perspective is easier than mentally “performing” the movement, yet the body responds in the same way — HSE scientists have found. This discovery changes the approach to rehabilitation after injuries and strokes.

An international group of scientists led by the Center for Neuroeconomics and Cognitive Research at HSE University has established that the effect of mentally reproducing movements (motor imagery) depends on how exactly a person imagines the action — through their own eyes (first-person perspective) or from an external viewpoint (third-person perspective) — as well as on which muscles are involved.

In an experiment using transcranial magnetic stimulation (TMS), 19 healthy volunteers were asked to mentally perform flexion and extension of the arm with a dumbbell in time with a metronome. Participants used three types of motor imagery: kinesthetic (feeling the movement), visual first-person (seeing their own hands), and visual third-person (observing themselves from the outside).

Key finding: For the shoulder muscles (biceps and triceps), third-person imagery proved to be just as effective as kinesthetic imagery — both significantly outperformed first-person visual imagery. At the same time, all three types of imagery had an equal effect on the hand muscles.

The authors conclude that proximal (large) muscles are more sensitive to the perspective of imagination than distal (small) muscles. The results have direct practical implications for neurorehabilitation and sports: third-person visualization (for example, watching a short video of oneself from the side) can be just as powerful a tool for restoring arm function after injuries or strokes as “feeling” the movement, while being easier to master.

The results were published in Scientific Reports.