Neural Control of Movement Laboratory

Digit Forces

Digit Forces and Perception of Digit Distance

Motivated by our findings on the interplay between sensory cues of digit position and digit force control,1,2 we have been investigating whether and how inputs associated with force production elicited at the fingertip drive the estimation of inter-digit distance. This work revealed that, in context of manipulation, digit distance estimation is influenced by the hand used to sense (and reproduce) finger configuration as well as by the distance between the digits in contact with the grasped object.3 We have also shown that the direction of force exerted by the fingertip4 elicit a bias in digit distance estimation in the same direction of the force. We have recently combined psychophysical methods and haptic interfaces to quantify the contribution of tactile and non-tactile (motor and proprioception, respectively) signals underlying perception of fingertip relative position5 (Fig. 2). Ongoing work is investigating whether the relative magnitude of motor commands and sensory cues modulate perception of fingertip distance.


Figure 2. Experimental design and set-up employed to quantify the contribution of tactile and non-tactile input of force for the estimation of finger relative position. From: Toma et al. (2019).


For more information on these projects contact: Simone Toma


  1. Fu Q., Zhang W., and Santello M. (2010). Anticipatory planning and control of grasp positions and Forces for dexterous two-digit manipulation. The Journal of Neuroscience.
  2. Fu Q., Hasan Z., and Santello M. (2011). Transfer of learned manipulation following changes in degrees of freedom. The Journal of Neuroscience.
  3. Shibata D., Choi J.Y., Laitano J.C., Santello M. (2013). Haptic motor transformation for the control of finger position. Plos One.
  4. Shibata D., Kapper A.M.L., and Santello M. (2014). Digit Forces bias sensorimotor transformations underlying control of fingertip position. Frontiers in Human Neuroscience.
  5. Toma S., Shibata D., Chinello F., Praticchizzo D., Santello M. (2019). Linear integration of tactile and non-tactile inputs mediates estimation of fingertip relative position. Frontiers in Neuroscience.