Fig. 6: Validation and performance comparison of the ATSS sensorimotor algorithm.

a Active Grasping Phase: The left column illustrates the synchronous evolution of neural activation level of muscle synergy and contact pressure captured by the ATSS during an active grasping task. Computed biological and ATSS-generated 2nd order tactile afferent signals are juxtaposed, revealing the system’s ability to emulate human tactile feedback patterns. Here the 2nd order biological afferent tactile signals were computed through our numerical 1st and 2nd neuron model presented before. b Reactive Grasping Phase: The right column presents the reactive phase where the ATSS adjusts to sudden contact, indicated by the dashed lines, with delayed neural activation and pressure adaptation. This response is compared with the biological benchmarks, with the lower charts displaying the corresponding afferent tactile signals. These graphs collectively demonstrate the temporal accuracy and the neuromorphic efficacy of the ATSS, simulating human like sensorimotor functions as per the summarized transduction function. Statistical evaluations using Mann-Whitney U tests reveal significant differences in firing rates and Victor-Purpura distances (p < 0.03 and p < 0.01, respectively), demonstrating the enhanced capability of Victor-Purpura distances in discriminating tactile stimuli. This supports their potential utility in developing advanced tactile feedback mechanisms for prosthetic and robotic applications.