How Weight Affects the Perceived Spacing between the Thumb and Fingers during Grasping.
We know much about mechanisms determining the perceived size and weight of lifted objects, but little about how these properties of size and weight affect the body representation (e.g. grasp aperture of the hand). Without vision, subjects (n = 16) estimated spacing between fingers and thumb (perceiv...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2015-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC4440696?pdf=render |
| _version_ | 1818041343615696896 |
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| author | Annie A Butler Martin E Héroux Simon C Gandevia |
| author_facet | Annie A Butler Martin E Héroux Simon C Gandevia |
| author_sort | Annie A Butler |
| collection | DOAJ |
| description | We know much about mechanisms determining the perceived size and weight of lifted objects, but little about how these properties of size and weight affect the body representation (e.g. grasp aperture of the hand). Without vision, subjects (n = 16) estimated spacing between fingers and thumb (perceived grasp aperture) while lifting canisters of the same width (6.6cm) but varied weights (300, 600, 900, and 1200 g). Lifts were performed by movement of either the wrist, elbow or shoulder to examine whether lifting with different muscle groups affects the judgement of grasp aperture. Results for perceived grasp aperture were compared with changes in perceived weight of objects of different sizes (5.2, 6.6, and 10 cm) but the same weight (600 g). When canisters of the same width but different weights were lifted, perceived grasp aperture decreased 4.8% [2.2 ‒ 7.4] (mean [95% CI]; P < 0.001) from the lightest to the heaviest canister, no matter how they were lifted. For objects of the same weight but different widths, perceived weight decreased 42.3% [38.2 ‒ 46.4] from narrowest to widest (P < 0.001), as expected from the size-weight illusion. Thus, despite a highly distorted perception of the weight of objects based on their size, we conclude that proprioceptive afferents maintain a reasonably stable perception of the aperture of the grasping hand over a wide range of object weights. Given the small magnitude of this 'weight-grasp aperture' illusion, we propose the brain has access to a relatively stable 'perceptual ruler' to aid the manipulation of different objects. |
| first_indexed | 2024-12-10T08:28:55Z |
| format | Article |
| id | doaj.art-3fb20fc5ac34404c93afcba051492b14 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-10T08:28:55Z |
| publishDate | 2015-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-3fb20fc5ac34404c93afcba051492b142022-12-22T01:56:09ZengPublic Library of Science (PLoS)PLoS ONE1932-62032015-01-01105e012798310.1371/journal.pone.0127983How Weight Affects the Perceived Spacing between the Thumb and Fingers during Grasping.Annie A ButlerMartin E HérouxSimon C GandeviaWe know much about mechanisms determining the perceived size and weight of lifted objects, but little about how these properties of size and weight affect the body representation (e.g. grasp aperture of the hand). Without vision, subjects (n = 16) estimated spacing between fingers and thumb (perceived grasp aperture) while lifting canisters of the same width (6.6cm) but varied weights (300, 600, 900, and 1200 g). Lifts were performed by movement of either the wrist, elbow or shoulder to examine whether lifting with different muscle groups affects the judgement of grasp aperture. Results for perceived grasp aperture were compared with changes in perceived weight of objects of different sizes (5.2, 6.6, and 10 cm) but the same weight (600 g). When canisters of the same width but different weights were lifted, perceived grasp aperture decreased 4.8% [2.2 ‒ 7.4] (mean [95% CI]; P < 0.001) from the lightest to the heaviest canister, no matter how they were lifted. For objects of the same weight but different widths, perceived weight decreased 42.3% [38.2 ‒ 46.4] from narrowest to widest (P < 0.001), as expected from the size-weight illusion. Thus, despite a highly distorted perception of the weight of objects based on their size, we conclude that proprioceptive afferents maintain a reasonably stable perception of the aperture of the grasping hand over a wide range of object weights. Given the small magnitude of this 'weight-grasp aperture' illusion, we propose the brain has access to a relatively stable 'perceptual ruler' to aid the manipulation of different objects.http://europepmc.org/articles/PMC4440696?pdf=render |
| spellingShingle | Annie A Butler Martin E Héroux Simon C Gandevia How Weight Affects the Perceived Spacing between the Thumb and Fingers during Grasping. PLoS ONE |
| title | How Weight Affects the Perceived Spacing between the Thumb and Fingers during Grasping. |
| title_full | How Weight Affects the Perceived Spacing between the Thumb and Fingers during Grasping. |
| title_fullStr | How Weight Affects the Perceived Spacing between the Thumb and Fingers during Grasping. |
| title_full_unstemmed | How Weight Affects the Perceived Spacing between the Thumb and Fingers during Grasping. |
| title_short | How Weight Affects the Perceived Spacing between the Thumb and Fingers during Grasping. |
| title_sort | how weight affects the perceived spacing between the thumb and fingers during grasping |
| url | http://europepmc.org/articles/PMC4440696?pdf=render |
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