Weighting of vision and proprioception in post-stroke reach planning
Johannes Keyser, Noël L. W. Keijsers, Luc P. J. Selen and W.
Radboud University Nijmegen, Donders Institute for Brain, Cognition and
Behaviour, Nijmegen, The Netherlands
Department of Research, Sint Maartenskliniek Nijmegen, The Netherlands
Keywords: Sensorimotor, motor control, optimality
Support: EU FP7 604063 HealthPAC
To plan a goal-directed reach, the brain estimates the initial hand
location by weighting visual and proprioceptive signals.
Sober & Sabes (2003) proposed a model of reach planning in two stages
, each with different sensory weightings for hand location
estimation: One weighting to determine a desired movement vector and one
to generate a joint-based motor command. Fitting the model to reach data
of healthy subjects revealed that the sensory weighting is shifted
towards vision during movement vector planning, but shifted towards
proprioception during motor command generation [1, 2, 3].
In our study, we quantify the weighting of vision and proprioception for
reach planning in stroke survivors and healthy controls. Participants
perform a center-out reaching task, with each hand, in a virtual reality
setup that allows to shift the visual feedback of the hand. We extended
Sober & Sabes' model to compare the affected versus unaffected hands of
stroke survivors and the dominant versus non-dominant hands of control
subjects. Our preliminary results show that the sensory weightings of
controls do not depend on hand dominance. We hypothesize that stroke
survivors show deficient sensory weightings with their affected hand,
either during movement vector computation or during motor command
 Sober SJ, Sabes PN. Multisensory integration during motor planning.
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 Sober SJ, Sabes PN. Flexible strategies for sensory integration
during motor planning. Nat Neurosci 8: 490–497, 2005.
 Taig E, Küper M, Theysohn N, Timmann D, Donchin O. Deficient use of
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Neurosci 32: 16274–16284, 2012