Experiment 1: tactile tilt aftereffect

Participants sat in front of a screen with their right hand resting on top of a box containing the tactile device. A schematic plot is shown in Fig. 1a. Each session began with a preliminary test lasting approximately five minutes to determine for each participant which of the three orientation ranges was best suited to their tactile orientation acuity to ensure a better-fitting psychometric function (Fig. 1d). This also acted as the practice block to familiarize the participant with the task. The main test contains six blocks, with adaptor orientations (left vs. right) alternating between blocks, and the order counterbalanced between subjects. Each trial began with the tactile grating rising from inside the box to the level of the participant’s fingertip already rotated to the adaptor orientation used for that block. Participants passively felt the orientation for the duration of the adaptation phase (30 s for initial adaptation, 5 s top-ups thereafter). After the adaptation phase, and a gap of 500 ms, the test stimulus was then presented to the participant through the tactile device for 1.5 s, and the participant was cued to passively feel the orientation of the test stimuli with their fingertip, and then report whether the stimulus orientation was left (anticlockwise) or right (clockwise) compared to vertical (proximal-distal orientation) by pressing the arrow keys with the other hand (See Fig.​Fig.22a).