Unusual prism adaptation reveals how grasping is controlled
- Vrije Universiteit Amsterdam, Netherlands
Figures
Figure 1
The prisms’ effects on the individual digits, grip aperture and grip position.
Overview of the individual digits throughout the experiment (A) and a detailed view of the grip aperture (B) and grip position (C) for the grasping movements performed in the pre- and post- …
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Figure 1—source data 1
Positions at 1 cm before crossing the board for of all trials underlying Figure 1 and the summary data underlying the central parts of Figure 1B,C.
- https://doi.org/10.7554/eLife.21440.004
Figure 2
Top and side views of the experimental setup.
The subject performs a single-digit pointing trial with the index finger. During single-digit trials, participants viewed the target block monocularly through a prism that was in front of the …
Appendix 1—figure 1
Data of the control experiment on the transfer of adaptation from single-digit pointing movements to the grip position in grasping.
Participants started with 6 grasping trials (pre-adaptation; grey background). Subsequently, they made 24 pointing movements with either the index finger or thumb while wearing leftward deviating …
Appendix 2—figure 1
Data of the control experiment on the effect of digit-eye pairing.
(A) The participants made pointing movements with either the unseen index finger (purple) or thumb (green) of their dominant hand (the right hand for 7 of the 8 participants). During adaptation …
Videos
Video 1
Example trials.
Three single digit trials (adaptation phase) and two grasping trials of one subject (pre- and post-adaptation phases). Note the presence/absence of the prisms, and the opening of the shutter glasses …
Tables
Table 1
Whether or not adapting the two digits to opposite prisms during pointing movements would be expected to influence grip position and grip aperture during subsequent grasping movements according to the three main theories about the control of grasping.
https://doi.org/10.7554/eLife.21440.002| Expected influence on | ||
|---|---|---|
| Controlled in grasping | Grip position | Grip aperture |
| Grip aperture and wrist position | No | No |
| Grip aperture and thumb position | Yes | No |
| Finger position and thumb position | No | Yes |
Additional files
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Transparent reporting form
- https://doi.org/10.7554/eLife.21440.007
