TY - JOUR T1 - Time-to-target simplifies optimal control of visuomotor feedback responses JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0514-19.2020 SP - ENEURO.0514-19.2020 AU - Justinas Česonis AU - David W. Franklin Y1 - 2020/03/20 UR - http://www.eneuro.org/content/early/2020/03/20/ENEURO.0514-19.2020.abstract N2 - Visuomotor feedback responses vary in intensity throughout a reach, commonly explained by optimal control. Here we show that the optimal control for a range of movements with the same goal can be simplified to a time-to-target dependent control scheme. We measure our human participants’ visuomotor responses in five reaching conditions, each with different hand or cursor kinematics. Participants only produced different feedback responses when these kinematic changes resulted in different times-to-target. We complement our experimental data with a range of finite and non-finite horizon optimal feedback control models, finding that the model with time-to-target as one of the input parameters best replicates the experimental data. Overall, this suggests that time-to-target is a critical control parameter in online feedback control. Moreover, we propose that for a specific task and known dynamics, humans can instantly produce a control signal without any additional online computation allowing rapid response onset and close to optimal control.Significance statement Human behaviour has widely been explained using stochastic optimal feedback control (OFC), formulating movement control as a set of time-dependent feedback and control gains. However, OFC is computationally expensive leading to questions about whether such a theory could be implemented in real time. Here we show that optimal feedback control could be approximated by a simple relationship between feedback gains and the time-to-target over a variety of movement kinematics, matching the evolution of visuomotor feedback gains of our human participants during reaching. As this relationship to time-to-target is similar across a wide range of kinematics, this suggests that early stages of the OFC controlled movement could be approximated by a time-to-target control, saving computational costs and allowing for rapid execution. ER -