Fig. 5

Example Tapping and Blinking Signal: a Line plot. Tapping and blinking signals are visualized throughout the examination of the GTR. Blue peaks show the tapping of the glabella region on the participant’s forehead while red peaks visualize when blinks were detected; b Line plot. To differentiate blinks as a response to the tapping of the glabella from other blinks, blinks were divided into two groups: reflex blinks, which occurred in the time frame from 50 ms before until 200 ms after the tapping signal, and non-reflex blinks in between two consecutive taps, but outside of the aforementioned time range. The blinking duration was defined as the width of each blink, which was calculated at half prominence. a.u. = arbitrary unit