Abstract
Grip force has been studied widely in a variety of interaction and movement tasks, however, not much is known about the timing of the grip force control in preparation for interaction with objects. For example, it is unknown whether and how the temporal preparation for a collision is related to (the prediction of) the impact load. To study this question, we examined the anticipative timing of the grip force in preparation for impact loads. We designed a collision task with different types of load forces in a controlled virtual environment. Participants interacted with a robotic device (KINARM, BKIN Technologies, Kingston) whose handles were equipped with force sensors which the participants held in precision grip. Representations of the hand and objects were visually projected on a virtual reality display and forces were applied onto the participant’s hand to simulate a collision with the virtual objects. The collisions were alternating between the two hands to allow transfer and learning between the hands. The results show that there is immediate transfer of object information between the two hands, since the grip force levels are (almost) fully adjusted after one collision with the opposite hand. The results also show that the grip force levels are nicely adjusted based on the mass and stiffness of the object. Surprisingly, the temporal onset of the grip force build up did not depend on the impact load, so that participants avoid slippage by adjusting the other grip force characteristics (e.g., grip force level and rate of change), therefore considering these self-imposed timing constraints. With the use of catch trials, for which no impact occurred, we further analyzed the temporal profile of the grip force. The catch trial data showed that the timing of the grip force peak is also independent of the impact load and its timing, which suggests a time-locked planning of the complete grip force profile.
Original language | English |
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Pages (from-to) | 2585-2594 |
Number of pages | 10 |
Journal | Experimental Brain Research |
Volume | 237 |
Issue number | 10 |
DOIs | |
Publication status | Published - 1 Oct 2019 |
Externally published | Yes |
Funding
The authors would like to thank Laurane Guiot, for her help to collect the data and design the protocol, as well as the participants of this study for their kind participation in this time- and energy-consuming experiment. This research was supported by a Rubicon Grant (446-17-003) from the Netherlands Organization of Scientific Research (NWO) (to IAK), by a Grant from the European Space Agency, ARC (Actions de Recherche Concertée), Prodex, and IAP VII/19 DYSCO (BELSPO, Belgian Federal Government).
Keywords
- Anticipation
- Collision
- Grip force
- Motor planning
- Timing