Abstract
Research has demonstrated that people will adopt initially awkward grasps if they afford more comfortable postures at the end of the movement. This end-state comfort effect provides evidence that humans represent future posture states and select appropriate grasps in anticipation of these postures. The purpose of the study was to examine to what extent the final action goal of a task influences motor planning of preceding segments, and whether grasp postures are planned to optimize end-state comfort during a three-segment action sequence in which two objects are manipulated, and participants can select from a continuous range of possible grasp postures. In the current experiment, participants opened a drawer, grasped an object from inside the drawer, and placed it on a table in one of the three target orientations (0°, 90°, or 180° object rotation required). Grasp postures during the initial movement segment (drawer opening) were not influenced by the final action goal (i.e., required target orientation). In contrast, both the intermediate (i.e., object grasping) and the final movement segment (i.e., object placing) were influenced by target orientation. In addition, participants adopted different strategies to achieve the action goal when the object required 180° rotation, with 42 % of participants prioritizing intermediate-state comfort and 58 % prioritizing end-state comfort. The results indicate that individuals optimize task performance by selecting lower level constraints that allow for successful completion of the action goal and that the selection of these constraints is dependent upon contextual, environmental, and internal influences.
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Notes
When participants made adjustments to initial grasp posture, they typically did so by changing the placement of the individual fingers, rather than rotating the whole hand.
In order to control for perceptual effects associated with target perception, the spatial arrangement of the coloured marks on target board was randomized.
The 0° rotation (up) condition was used as a baseline measure of grasp behavior.
Inspection of the data revealed that if the direction of object rotation differed from their typical strategy (e.g., rotating the object counterclockwise, when they typically rotated the object clockwise), this usually occurred in the first two trials. There were no observable differences in consistency between participants.
Because the assessment of comfortable hand orientation angles differed considerably from the assessment of grasp postures during the main experiment (i.e., different sample population, task, and instructions), the data are compared qualitatively, rather than quantitatively.
References
Alberts JL, Saling M, Stelmach GE (2002) Alterations in transport path differentially affect temporal and spatial movement parameters. Exp Brain Res 143:417–425
Ansuini C, Giosa L, Turella L, Altoè G, Castiello U (2008) An object for an action, the same object for other actions: effects on hand shaping. Exp Brain Res 185:111–119
Armbruester C, Spijkers W (2006) Movement planning in prehension: do intended actions influence the initial reach and grasp movement? Mot Cont 10:311–329
Fischman MG, Stodden DF, Lehman DM (2003) The end-state comfort effect in bimanual grip selection. Res Q Exerc Sport 74:17–24
Haggard P (1998) Planning of action sequences. Acta Psychol 99:201–215
Haggard P, Wing A (1998) Coordination of hand aperture with the spatial path of hand transport. Exp Brain Res 118:286–292
Herbort O, Butz MV (2010) Planning and control of hand orientation in grasping movements. Exp Brain Res 202:867–878
Herbort O, Butz MV (2012) The continuous end-state comfort effect: weighted integration of multiple biases. Psychol Res 76:345–363
Hesse C, Deubel H (2010a) Effects of altered transport paths and intermediate movement goals on human grasp kinematics. Exp Brain Res 201:93–109
Hesse C, Deubel H (2010b) Advance planning in sequential pick-and-place tasks. J Neurophysiol 104:508–516
Hughes CML, Franz EA (2008) Goal-related planning constraints in bimanual grasping and placing of objects. Exp Brain Res 188:541–550
Hughes CML, Haddad JM, Franz EA, Zelaznik HN, Ryu JH (2011) Physically coupling two objects in a bimanual task alters kinematics but not end-state comfort. Exp Brain Res 211:219–229
Hughes CML, Seegelke C, Schack T (2012a) The influence of initial and final precision on motor planning: individual differences in end-state comfort during unimanual grasping and placing. J Mot Behav 44:195–201
Hughes CML, Seegelke C, Reißig P, Schütz C (2012b) Effects of stimulus cueing on bimanual grasp posture planning. Exp Brain Res 219:391–401
Janssen L, Crajé C, Weigelt M, Steenbergen B (2010) Motor planning in bimanual object manipulation: two plans for two hands? Mot Cont 14:240–254
Jeannerod M (1981) Intersegmental coordination during reaching at natural visual objects. In: Long J, Baddelay A (eds) Attention and performance IX. Erlbaum, Hillsdale, pp 153–168
Jeannerod M (1984) The timing of natural prehension movements. J Mot Behav 16:235–254
Marteniuk RG, MacKenzie CL, Jeannerod M, Athenes S, Dugas C (1987) Constraints on human arm movement trajectories. Can J Psychol 41:365–378
Oldfield RC (1971) The assessment and analysis of handedness: the Edinburgh inventory. Neuropsychologia 9:97–113
Rand MK, Stelmach GE (2000) Segment interdependency and difficulty in two-stroke sequences. Exp Brain Res 134:228–236
Rosenbaum DA, Marchack F, Barnes HJ, Vaughan J, Slotta JD, Jorgensen MJ (1990) Constraints for action selection: overhand versus underhand grips. In: Jeannerod M (ed) Attention and performance XIII. Erlbaum, Hillsdale, pp 321–342
Rosenbaum DA, Vaughan J, Jorgensen MJ, Barnes HJ, Stewart E (1993) Plans for object manipulation. In: Meyer DE, Kornblum S (eds) Attention and performance XIV (silver jubilee volume): synergies in experimental psychology, artificial intelligence, and cognitive neuroscience. MIT Press, Cambridge, pp 803–820
Rosenbaum DA, van Heugten CM, Caldwell GE (1996) From cognition to biomechanics and back: the end-state comfort effect and the middle-is-faster effect. Acta Psychol 94:59–85
Rosenbaum DA, Meulenbrock RG, Vaughan J (2006) Plans for grasping objects. In: Latash M, Lestienne F (eds) Motor control and learning over the lifespan. Springer, New York, pp 9–25
Seegelke C, Hughes CML, Schack T (2011) An investigation into manual asymmetries in grasp behavior and kinematics during an object manipulation task. Exp Brain Res 215:65–75
Short MW, Cauraugh JH (1999) Precision hypothesis and the end-state comfort effect. Acta Psychol (Amst) 100:243–252
Studenka BE, Seegelke C, Schütz C, Schack T (2012) Posture based motor planning in a sequential grasping task. J Appl Res Mem Cogn 1:89–95
Weigelt M, Kunde W, Prinz W (2006) End-state comfort in bimanual object manipulation. Exp Psychol 53:143–148
Wu G, van der Helm FCT, Veeger HEJ, Makhsous M, van Roy P, Anglin C, Nagels J, Karduna AR, McQuade K, Wang X, Werner FW, Buchholz B (2005) ISB recommendation on definitions of joint coordinate systems of various joints for the reporting of human joint motion—part II: shoulder, elbow, wrist and hand. J Biomech 38:981–992
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Seegelke, C., Hughes, C.M.L., Schütz, C. et al. Individual differences in motor planning during a multi-segment object manipulation task. Exp Brain Res 222, 125–136 (2012). https://doi.org/10.1007/s00221-012-3203-8
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DOI: https://doi.org/10.1007/s00221-012-3203-8