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Learning arm/hand coordination with an altered visual input.

Iftime Nielsen SD, Dosen S, Popović MB, Popović DB - Comput Intell Neurosci (2010)

Bottom Line: We found substantial trajectory errors and an increased execution time at the baseline of the study.We also found that trajectory errors decreased in all conditions after three days of practice with the altered vision in the F condition only for 20 minutes per day, suggesting that recalibration of the visual systems occurred relatively quickly.The results also suggest that recalibration is more difficult to achieve for altered vision in the F and L conditions compared to the T condition.

View Article: PubMed Central - PubMed

Affiliation: Department of Health Science and Technology, Center for Sensory-Motor Interaction, Aalborg University, DK-9220 Aalborg, Denmark.

ABSTRACT
The focus of this study was to test a novel tool for the analysis of motor coordination with an altered visual input. The altered visual input was created using special glasses that presented the view as recorded by a video camera placed at various positions around the subject. The camera was positioned at a frontal (F), lateral (L), or top (T) position with respect to the subject. We studied the differences between the arm-end (wrist) trajectories while grasping an object between altered vision (F, L, and T conditions) and normal vision (N) in ten subjects. The outcome measures from the analysis were the trajectory errors, the movement parameters, and the time of execution. We found substantial trajectory errors and an increased execution time at the baseline of the study. We also found that trajectory errors decreased in all conditions after three days of practice with the altered vision in the F condition only for 20 minutes per day, suggesting that recalibration of the visual systems occurred relatively quickly. These results indicate that this recalibration occurs via movement training in an altered condition. The results also suggest that recalibration is more difficult to achieve for altered vision in the F and L conditions compared to the T condition. This study has direct implications on the design of new rehabilitation systems.

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End points of trajectories under the F, L, and T experimental conditions for one representative subject on Day 1 (star) and Day 5 (full circle). The three circles with 8 cm diameter correspond to the initial hand position (circle 1) and the contralateral (circle 2) and ipsilateral (circle 3) circles in the workspace. End points of the trajectories (for 9 trials) are plotted for sequence 1 and sequence 2.
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fig4: End points of trajectories under the F, L, and T experimental conditions for one representative subject on Day 1 (star) and Day 5 (full circle). The three circles with 8 cm diameter correspond to the initial hand position (circle 1) and the contralateral (circle 2) and ipsilateral (circle 3) circles in the workspace. End points of the trajectories (for 9 trials) are plotted for sequence 1 and sequence 2.

Mentions: The latter is also demonstrated in Figure 4, which shows only the end points of the sequence trajectories on Days 1 and 5. On Day 5, the end-point clusters were less spread out, and their centers converged more towards the reference positions.


Learning arm/hand coordination with an altered visual input.

Iftime Nielsen SD, Dosen S, Popović MB, Popović DB - Comput Intell Neurosci (2010)

End points of trajectories under the F, L, and T experimental conditions for one representative subject on Day 1 (star) and Day 5 (full circle). The three circles with 8 cm diameter correspond to the initial hand position (circle 1) and the contralateral (circle 2) and ipsilateral (circle 3) circles in the workspace. End points of the trajectories (for 9 trials) are plotted for sequence 1 and sequence 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2913529&req=5

fig4: End points of trajectories under the F, L, and T experimental conditions for one representative subject on Day 1 (star) and Day 5 (full circle). The three circles with 8 cm diameter correspond to the initial hand position (circle 1) and the contralateral (circle 2) and ipsilateral (circle 3) circles in the workspace. End points of the trajectories (for 9 trials) are plotted for sequence 1 and sequence 2.
Mentions: The latter is also demonstrated in Figure 4, which shows only the end points of the sequence trajectories on Days 1 and 5. On Day 5, the end-point clusters were less spread out, and their centers converged more towards the reference positions.

Bottom Line: We found substantial trajectory errors and an increased execution time at the baseline of the study.We also found that trajectory errors decreased in all conditions after three days of practice with the altered vision in the F condition only for 20 minutes per day, suggesting that recalibration of the visual systems occurred relatively quickly.The results also suggest that recalibration is more difficult to achieve for altered vision in the F and L conditions compared to the T condition.

View Article: PubMed Central - PubMed

Affiliation: Department of Health Science and Technology, Center for Sensory-Motor Interaction, Aalborg University, DK-9220 Aalborg, Denmark.

ABSTRACT
The focus of this study was to test a novel tool for the analysis of motor coordination with an altered visual input. The altered visual input was created using special glasses that presented the view as recorded by a video camera placed at various positions around the subject. The camera was positioned at a frontal (F), lateral (L), or top (T) position with respect to the subject. We studied the differences between the arm-end (wrist) trajectories while grasping an object between altered vision (F, L, and T conditions) and normal vision (N) in ten subjects. The outcome measures from the analysis were the trajectory errors, the movement parameters, and the time of execution. We found substantial trajectory errors and an increased execution time at the baseline of the study. We also found that trajectory errors decreased in all conditions after three days of practice with the altered vision in the F condition only for 20 minutes per day, suggesting that recalibration of the visual systems occurred relatively quickly. These results indicate that this recalibration occurs via movement training in an altered condition. The results also suggest that recalibration is more difficult to achieve for altered vision in the F and L conditions compared to the T condition. This study has direct implications on the design of new rehabilitation systems.

Show MeSH