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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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Velocity profiles of one representative subject for the four experimental conditions (N, F, L, and T) on Day 1 (left plots) and Day 5 (right plots). The four rows correspond to the four sequences of the movement. PV (m/s), AD (s), and DD (s) values are included for each sequence and each condition.
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fig6: Velocity profiles of one representative subject for the four experimental conditions (N, F, L, and T) on Day 1 (left plots) and Day 5 (right plots). The four rows correspond to the four sequences of the movement. PV (m/s), AD (s), and DD (s) values are included for each sequence and each condition.

Mentions: Figure 6 depicts the velocity profiles for one representative subject on Day 1 and on Day 5 under the four experimental conditions. Note that the velocities on Day 1 had unusual shapes (e.g., wavy and/or multimodal profiles). On Day 5, the velocities had near symmetrical bell-shaped profiles typical of normal reaching movements. Table 2 summarizes the movement parameters for the whole group under the four experimental conditions for Days 1 and 5. PV was higher for Day 5 than for Day 1 for all conditions and all movement sequences.


Learning arm/hand coordination with an altered visual input.

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

Velocity profiles of one representative subject for the four experimental conditions (N, F, L, and T) on Day 1 (left plots) and Day 5 (right plots). The four rows correspond to the four sequences of the movement. PV (m/s), AD (s), and DD (s) values are included for each sequence and each condition.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig6: Velocity profiles of one representative subject for the four experimental conditions (N, F, L, and T) on Day 1 (left plots) and Day 5 (right plots). The four rows correspond to the four sequences of the movement. PV (m/s), AD (s), and DD (s) values are included for each sequence and each condition.
Mentions: Figure 6 depicts the velocity profiles for one representative subject on Day 1 and on Day 5 under the four experimental conditions. Note that the velocities on Day 1 had unusual shapes (e.g., wavy and/or multimodal profiles). On Day 5, the velocities had near symmetrical bell-shaped profiles typical of normal reaching movements. Table 2 summarizes the movement parameters for the whole group under the four experimental conditions for Days 1 and 5. PV was higher for Day 5 than for Day 1 for all conditions and all movement sequences.

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