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Projects

The Sensorimotor Research Lab

The Sensorimotor Research Lab is part of the Donders Institute for Brain, Cognition and Behaviour at the Radboud University Nijmegen, and housed within the Donders Centre for Cognition. The objective of our research group is to elucidate the computational and neural strategies in human sensorimotor processing, using modeling, psychophysical and neuroimaging techniques. Our main focus is on how sensory information is transformed into spatial representations and motor actions and how different spatial and motor representations are updated and/or maintained during self-motion.

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Optimal control and Bayesian models are developed to guide our research. A vestibular motion platform, a haptic device (Phantom) and a robotic manipulandum (vBot), all associated with virtual reality and combined with kinematic recording techniques for eye, head and limb-movements (Eyelink, Optotrak), facilitate our behavioral experiments. Neuroimaging (fMRI, EEG and MEG) and perturbation techniques (TMS/tDCS/GVS) are used to identify the neural circuitry and neuronal communication for sensorimomotor integration, particularly in cerebral cortex. Our research objective is pursued from a neuroscience systems point of view, with research projects studying topics such as spatial perception, visuospatial updating, multisensory integration, effector selection, motor learning, and sensory-guided actions of eye and limb movements. Recently, we have started to also exploit our experimental paradigms in clinical settings to understand the fundamental mechanisms that underlie the disorders in patients with sensorimotor deficits. The group contributes to the Perception, Action, and Control research theme of the Donders Institute.

Spatial constancy

Moving through the environment causes complex changes of sensory and motor inputs to the brain. Yet, despite our motion, we perceive the world as stable and interact with the objects in it with great accuracy. This ability to maintain a veridical representation of space during self-motion is called spatial constancy and is an important component in the control of goal-directed actions. We study the signals and mechanisms involved in making spatially-accurate eye and reaching movements in a dynamic 3-D environment. Projects are:

1. Spatial updating across saccades  
2. Spatial updating in interceptive motor behavior
3. Spatially-guided motor behavior during self-motion

Recent publications:

  • Gutteling T., Selen L.J.P., Medendorp W.P. Parallax-sensitive remapping of visual space in occipito-parietal alpha-band activity during whole-body motion. Journal of Neurophysiology, 113:1574-84, 2015
  • Atsma J., Maij F., Corneil B.D., and Medendorp W.P. No peri-saccadic mislocalization with abruptly cancelled saccades. Journal of Neuroscience, 34: 5497-504, 2014
  • Van Der Werf J., Buchholz V.N., Jensen O., Medendorp W.P. Reorganization of oscillatory activity in human parietal cortex during spatial updating. Cerebral Cortex, 23, 508-519, 2013.
  • Crawford J.D., Henriques D.Y.P., Medendorp W.P. Three-dimensional transformations for goal-directed action Annual Review of Neuroscience, 34:309-31, 2011.
  • Medendorp W.P. Spatial constancy mechanisms in motor control Philos Trans R Soc Lond B Biol Sci., 366: 476-491, 2011


Dynamic perception using ambiguous signals

To ensure perceptual stability, we use information about self-orientation and self-motion from various sensory modalities, in particular the visual and vestibular system. The vestibular system has specialized organs for detecting rotational acceleration (the semicircular canals) and for sensing linear acceleration (the otoliths), but they provide noisy and partly ambiguous information. We study how brain deals with imperfect sensory signals when creating a percept of the world. Projects are:

1. Dynamic perceptual updating by vestibular signals
2. Role of top-down signals in visual motion detection
3. Dynamic perception during linear motion

Recent publications:

  • Alberts BBGT, Selen, LPJ, Verhagen, WIM, Medendorp WP. Sensory Substitution in Bilateral Vestibular a-Reflexic Patients. Physiological Reports. Vol. 3 no. e12385, 2015.
  • Maij F., Wing A.M., and Medendorp W.P. Spatiotemporal integration for tactile localization during arm movements: a probabilistic approach. Journal of Neurophysiology, 110: 2661-9, 2013
  • Clemens I.A.H.*, De Vrijer M.*, Selen L.P.J., Van Gisbergen J.A.M, Medendorp W.P. Multisensory processing in spatial orientation: an inverse probabilistic approach Journal of Neuroscience, 31(14), 5365-5377, 2011 (*: authors contributed equally)
  • Vingerhoets, R.A.A., De Vrijer, M., Van Gisbergen, J.A.M. & Medendorp, W.P. Fusion of visual and vestibular tilt cues in the perception of visual vertical. J Neurophysiol, 101(3), 1321-1333, 2009


Neural dynamics in sensorimotor integration

How are spatial signals integrated with motor effector signals in order to plan an action? The posterior parietal cortex is known to be an important site for sensorimotor integration in the brain, but its temporal dynamics and computational constraints are not well understood. We examine sensorimotor integration in saccade and reaching tasks, recording neural activity with fMRI and and whole-head magnetoencephalography (MEG). Projects are:

  1. Effector selection in the human brain
  2. Temporal dynamics of human brain activity in sensorimotor integration
  3. Decoding global maps in the human motor system
  4. Role of oscillatory activity in coding multimodal spatial representations for eye and hand actions
  5. Motor planning for multiple effectors in the human intraparietal sulcus

Recent publications:

  • Leone F.T.H., Heed, T., Toni I., and Medendorp W.P. Understanding effector selectivity in human posterior parietal cortex by combining information patterns and activation measures. Journal of Neuroscience, 34: 7102-12, 2014.
  • Buchholz VN, Jensen O, Medendorp WP. Parietal oscillations code non-visual reach targets relative to gaze and body. Journal of Neuroscience, 33: 3492-9, 2013
  • Heed T., Beurze S.M., Toni I., Roder B., Medendorp W.P. Functional rather than effector-specific organization of human posterior parietal cortex. Journal of Neuroscience, 31: 3066-3076, 2011
  • Medendorp W.P., Buchholz V.N., Van Der Werf J., Leone F.T.H. Parietofrontal circuits in goal-oriented behavior European Journal of Neuroscience, 33:2017-27, 2011

Sensorimotor adaptation

The brain uses accurate internal models of the kinematics and dynamics its sensorimotor systems. These models must be continuously calibratedto the actual dynamics of the body and world.The process responsible for this calibration is called motor adaptation. When subjects make reaching movements against a specific force, imposed by a robotic manipulandum, or due to inertial motion, their movement trajectories are first skewed and deviant in the direction of the force, but with practice they gradually become smooth and more straight again. We study sensorimotor adapation in saccadic and reaching tasks, and how this process may be coordinated by the brain. Projects are:

  1. Contextual cues in sensorimotor adaptation
  2. Reach adaptation during body acceleration
  3. Role of sensorimotor adaptation in action selection

Recent publications:

  • Sarwary A., Selen L.J.P., and Medendorp W.P. Vestibular benefits to task savings in motor adaptation. Journal of Neurophysiology, 110: 1269-77, 2013.
  • Grent-'t-Jong T, Oostenveld R, Jensen O, Medendorp WP, Praamstra P. Competitive interactions in sensorimotor cortex: oscillations express separation between alternative movement targets. J Neurophysiol. 112:224-32, 2014.
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