Jeroen Smeets

Variability and adaptation

No two human movements are the same. For a scientist, there are various ways to deal with this phenomenon. A first approach is to regard the variability as departures from the average ideal movement due to neural noise. According to this view, a good movement strategy reduces the sensitivity for neural noise. A second approach is to regard variability as a sign of dexterity. According to this view, a good movement strategy exploits the variability, which can be used for flexible adjustments or adaptation. This last approach seems appropriate if we want to indicate what the qualities of a top soccer player are, whereas the first seems more appropriate to describe the qualities of a top dart-player. This distinction is not very clear-cut: the variability in taking penalty kicks should be low in soccer, while conversely we showed (Smeets et al., 2002) that a low variability is not important for all aspects of dart throwing. By a carefull analysis of the variability of goal-directed behviour, we can find out how the visuomotor transformation underlying that behaviour is structured.

Adaptation is a concept that is used to describe changes in sensorimotor behaviour in reponse to changes in sensory information. I propose that this change in behaviour is not due to a recalibration of the sensory information, but can be fully explained by a reweighting of information (Smeets et al., 2006).

Selected publications

• Smeets JBJ (1994) Biarticular muscles and the accuracy of motor control. Human Movement Science 13:587-600 (reprint)
• Smeets JBJ (2000) The relation between movement parameters and motor learning. Experimental Brain Research, 132:550-552. (reprint, DOI)
• Van den Dobbelsteen, J.J., Brenner E, Smeets JBJ (2001) Endpoints of arm movements to visual targets. Experimental Brain Research, 138:279-287. (reprint, DOI, comment in Neuroreport)
• Smeets JBJ, Frens MA, Brenner E (2002) Throwing darts: timing is not the limiting factor. Experimental Brain Research, 144:268-274 (reprint, DOI)
• Van den Dobbelsteen JJ, Brenner E, Smeets JBJ (2003) Adaptation of movement endpoints to perturbations of visual feedback. Experimental Brain Research, 148:471-481 (reprint, DOI)
• Smeets JBJ, Hooge ITC (2003) The nature of variability of saccades. Journal of Neurophysiology, 16:12-20. (reprint)
• van den Dobbelsteen JJ, Brenner E, Smeets JBJ (2004) Body-centered visuomotor adaptation. Journal of Neurophysiology 92: 416-423 (reprint, DOI)
• Brenner E, van Beers RJ, Rotman G, Smeets JBJ. (2006) The role of uncertainty in the systematic spatial mislocalisation of moving objects. Journal of Experimental Psychology: Human Perception and Performance 32:811-825 (reprint)
• Smeets JBJ, van den Dobbelsteen JJ, de Grave DDJ, van Beers RJ, Brenner E (2006) Sensory integration does not lead to sensory calibration. Proceedings of the National Academy of Sciences 103:18781-18786(DOI, reprint, supporting info)
• Brenner E, Granzier JJM, Smeets JBJ (2007) Combining local and global contributions to perceived colour: an analysis of the variability in symmetric and asymmetric colour matching. Vision Research, 47:114-125 (reprint, DOI)
• Smeets JBJ, Louw S (2007) The contribution of covariation to skill improvement is an ambiguous measure. Journal of Experimental Psychology: Human Perception and Performance 33:246-249 (reprint)
• Muller CPM, Brenner E, Smeets JBJ (2007) Living Up To Optimal Expectations Journal of Vision7(3):2,1-10(reprint, JOV)
• Van Mierlo CM, Brenner E, Smeets JBJ (2007) Temporal aspects of cue combination. Journal of Vision 7(7):8,1-11 (reprint, JOV)
• Brenner E, Mamassian P, Smeets JBJ (2008) If I saw it, it probably wasn’t far from where I was looking. Journal of Vision 8(2):7, 1-10 (reprint, JOV)
• Smeets JBJ, Brenner E (2008) Grasping Weber's Law. Current Biology 18:R1089-R1090 (reprint, DOI)
• Brenner E, Smeets JBJ (2009) Sources of variability in interceptive movements. Experimental Brain Research 195:117-133 (reprint, DOI)
• Muller CPM, Brenner E, Smeets JBJ (2009) Testing a counter-intuitive prediction of Optimal Cue Combination. Vision Research 49:134-139 (reprint, DOI)
• Muller, C.M.P., Brenner, E., Smeets, J.B.J. (2009) . Maybe they are all circles: clues and cues. Journal of Vision 9(9):10, 1-5 (reprint, JOV
• Slijper H, Richter J, Over E, Smeets J, Frens M. (2009) Statistics predict kinematics of hand movements during everyday activity. Journal of Motor Behavior 41:3-9 (reprint)
• Muller CMP, Brenner E, Smeets JBJ (2009) Different cue weights at the same place. Journal of Vision 9(11):26, 1-5 (reprint, JOV)
• Sousa R, Brenner E, Smeets JBJ (2010) A new binocular cue for absolute distance: disparity relative to the most distant structure. Vision Research, in press

My other areas of research are:

• Interception
• Prehension
• Illusions in perception and action.
• Perception of space-time
• Eye movements
• Search
• Other aspects of motor control
• Color vision