Effect of Tactile Stimulation on Hand Mental Rotation Among Young Healthy Adults: A Randomized Controlled Trial

In the hand mental rotation task, images and line drawings of hand at different angles are shown to the subjects, and they are asked to choose which hand (left or right) it is. Tactile stimulation is an appropriate technique to improve sensory and motor functions.

The present study aimed to investigate the impact of tactile stimulation on the hand mental rotation task.

To meet the study objectives, 91 right-handed university students were selected to participate in this study. They were randomly divided into control (n = 41) and tactile stimulation (n = 50) groups. Participants were asked to perform a hand mental rotation task before and after tactile stimulation. The task required participants to judge the laterality (left or right) of hands as quickly and accurately as possible. The tactile stimulation was applied to the right index fingertip (16 Hz for 30 min).

In the tactile stimulation group, all angles for both right- and left-hand participants were analyzed, demonstrating significant decreases in the reaction time (P = 0.004) after tactile stimulation (mean: 1,908.24 ± 375.42 to 1,721.21 ± 428.99 milliseconds). In this group, the response accuracy rate increased considerably (P < 0.001) after tactile stimulation (mean: 78.43% ± 16.58 to 84.38% ± 18.15). In the control group, no significant differences were found between the measured parameters before and after sham stimulation.

The current study demonstrated that tactile stimulation could improve hand mental rotation in healthy young adults, probably due to increased brain excitability and plasticity.