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The impact of aging on the spatial accuracy of quick corrective arm movements in response to sudden target displacement during reaching.

Kimura D, Kadota K, Kinoshita H - Front Aging Neurosci (2015)

Bottom Line: Results showed that, for the younger group, the variance in the directional error of the corrective response correlated with the variance in the reaching trajectory at the halfway point of the reach, but the correlation decreased at the end of the reaching.On the other hand, such correlations were not significant in elderly participants, although the variance of the directional error did not show a significant difference between age groups.Thus, the quick, corrective response seems to play an important role in decreasing variability, especially before the end of reaching, and aging can impair this process.

View Article: PubMed Central - PubMed

Affiliation: Biomechanics and Motor Control Laboratory, Graduate School of Medicine, Osaka University Toyonaka, Japan.

ABSTRACT
Age-related declines in visuomotor processing speed can have a large impact on motor performance in elderly individuals. Contrary to previous findings, however, recent studies revealed that elderly individuals are able to quickly react to displacement of a visual target during reaching. Here, we investigated the influence of aging on quick, corrective responses to perturbations during reaching in the terms of their functional contribution to accuracy. Elderly and young adults performed reaching movements to a visual target that could be displaced during reaching, and they were requested to move their hand to reach the final target location as quickly as possible. Results showed that, for the younger group, the variance in the directional error of the corrective response correlated with the variance in the reaching trajectory at the halfway point of the reach, but the correlation decreased at the end of the reaching. On the other hand, such correlations were not significant in elderly participants, although the variance of the directional error did not show a significant difference between age groups. Thus, the quick, corrective response seems to play an important role in decreasing variability, especially before the end of reaching, and aging can impair this process.

No MeSH data available.


(A) Group means for endpoint variability. The error bars denote SD. (B) Median of the directional differences for all stimulus directions broken down by group.
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Figure 4: (A) Group means for endpoint variability. The error bars denote SD. (B) Median of the directional differences for all stimulus directions broken down by group.

Mentions: Figure 4A shows the mean of the variability of the final reaching location, indicating a spatial consistency in reaching performance. ANOVA revealed neither a significant main effect of Group (F(1,48) = 0.241, p = 0.626) nor of the interaction (F(1,48) = 1.54, p = 0.192), but the main effect of Direction was significant (F(4,192) = 21.29, p < 0.0001). Post hoc comparison revealed that variability under the rightward target-displacement condition was significantly larger than under all other conditions (leftward: p < 0.0001, upward: p = 0.002, downward: p < 0.0001, control: p < 0.0001). The upward condition showed larger variability than that of the control condition (p = 0.039).


The impact of aging on the spatial accuracy of quick corrective arm movements in response to sudden target displacement during reaching.

Kimura D, Kadota K, Kinoshita H - Front Aging Neurosci (2015)

(A) Group means for endpoint variability. The error bars denote SD. (B) Median of the directional differences for all stimulus directions broken down by group.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4585039&req=5

Figure 4: (A) Group means for endpoint variability. The error bars denote SD. (B) Median of the directional differences for all stimulus directions broken down by group.
Mentions: Figure 4A shows the mean of the variability of the final reaching location, indicating a spatial consistency in reaching performance. ANOVA revealed neither a significant main effect of Group (F(1,48) = 0.241, p = 0.626) nor of the interaction (F(1,48) = 1.54, p = 0.192), but the main effect of Direction was significant (F(4,192) = 21.29, p < 0.0001). Post hoc comparison revealed that variability under the rightward target-displacement condition was significantly larger than under all other conditions (leftward: p < 0.0001, upward: p = 0.002, downward: p < 0.0001, control: p < 0.0001). The upward condition showed larger variability than that of the control condition (p = 0.039).

Bottom Line: Results showed that, for the younger group, the variance in the directional error of the corrective response correlated with the variance in the reaching trajectory at the halfway point of the reach, but the correlation decreased at the end of the reaching.On the other hand, such correlations were not significant in elderly participants, although the variance of the directional error did not show a significant difference between age groups.Thus, the quick, corrective response seems to play an important role in decreasing variability, especially before the end of reaching, and aging can impair this process.

View Article: PubMed Central - PubMed

Affiliation: Biomechanics and Motor Control Laboratory, Graduate School of Medicine, Osaka University Toyonaka, Japan.

ABSTRACT
Age-related declines in visuomotor processing speed can have a large impact on motor performance in elderly individuals. Contrary to previous findings, however, recent studies revealed that elderly individuals are able to quickly react to displacement of a visual target during reaching. Here, we investigated the influence of aging on quick, corrective responses to perturbations during reaching in the terms of their functional contribution to accuracy. Elderly and young adults performed reaching movements to a visual target that could be displaced during reaching, and they were requested to move their hand to reach the final target location as quickly as possible. Results showed that, for the younger group, the variance in the directional error of the corrective response correlated with the variance in the reaching trajectory at the halfway point of the reach, but the correlation decreased at the end of the reaching. On the other hand, such correlations were not significant in elderly participants, although the variance of the directional error did not show a significant difference between age groups. Thus, the quick, corrective response seems to play an important role in decreasing variability, especially before the end of reaching, and aging can impair this process.

No MeSH data available.