Body Position during Action Observation Facilitates Motor Imagery

[Purpose] The purpose of this study was to investigate whether the spatial coincidence of body parts during action observation improves motor imagery. [Participants and Methods] The participants were 24 right-handed healthy adults (15 males, 9 females, 21.3 ± 4 years old) who were randomly assigned to 3 groups: the proximal observation group, AON group; the distal observation group, AOF group; and a control group). The motor imagery task of this study was mental rotation of the hand (HMRT), and the reaction time was measured. First, HMRT was performed, then each group was observed for hand movement under different conditions. Finally, HMRT was performed again after action observation. [Results] There were no significant differences among the reaction times of the 3 groups before observation, but in the results after observation, the reaction time was significantly faster in the AON group than in the AOF and control groups. [Conclusion] The position of the body during action observation may affect motor imagery ability.