TaK: A Tactile Knob to Investigate Orientation Perception

The ability to perceive and interact with the surrounding environment is essential for human adaptation. For visually impaired individuals, touch plays a fundamental role in compensating for the absence of vision, enabling spatial awareness and navigation. Given the importance of touch in this population, various experiments have been carried out to explore their tactile abilities. However, reliable tools for assessing tactile perception of orientation and direction remain limited. To address this gap, we developed TaK (Tactile Knob), a tactile goniometer designed to measure how individuals perceive object orientation and direction. TaK features a manually adjustable spinning arrow, a 3D-printed base, electronic components for precise angle measurement, and a serial port to minimize reporting errors. We conducted two experiments to evaluate its effectiveness. In the first, sighted participants performed an orientation reproduction task using both TaK and a commercial knob. Results showed no significant differences between the two devices, confirming TaK's reliability in measuring tactile orientation perception, comparable to existing commercial tools. The second experiment compared sighted and visually impaired participants using TaK. Again, no significant differences were found, demonstrating its inclusivity and validity for assessing tactile perception in spatial tasks. These findings highlight TaK's potential as a reliable and accessible tool for spatial perception research and assistive technology development, contributing to a better understanding of tactile processing in both sighted and visually impaired individuals.