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We investigated whether deficits of adaptive improvement in seniors are related to an age-dependent decay of the brain's executive functions. Younger and older subjects completed a battery of cognitive tests, and preformed aimed arm movements before and during exposure to rotated visual feedback. In accordance with previous work, we found that adaptive(More)
Previous studies have found that sensorimotor adaptation to visual distortions is degraded in seniors compared with younger subjects, whereas after-effects on removal of the distortion are age-independent. The latter finding was interpreted as evidence that adaptive recalibration is not affected by old age, and that the observed degradation is therefore due(More)
Previous research has shown that subjects can adapt with either arm to an opposite visual distortion, and the two adaptive states can then be used in sequence to control the respective arm. To extend this finding, we exposed the left and right arms of our subjects to opposite-directed rotations of the visual field alternately for 20 s each, and determined(More)
This review summarizes our present knowledge about elderly people's problems with walking. We highlight the plastic changes in the brain that allow a partial compensation of these age-related deficits and discuss the associated costs and limitations. Experimental evidence for the crucial role of executive functions and working memory is presented, leading(More)
The present study investigates whether the acquisition of a rhythmical bimanual coordination pattern is influenced by existing intrinsic coordination tendencies. Participants were required to learn 1 of 5 new coordination patterns, whose relative phase phi was either 36, 60, or 90 degrees away from the 0 degree and 180 degree attractors, respectively. They(More)
  • Otmar Bock
  • 2008
BACKGROUND It has been suggested in the past that the ability to walk while concurrently engaging in a second task deteriorates in old age, and that this deficit is related to the high incidence of falls in the elderly. However, previous studies provided inconsistent findings about the existence of such an age-related dual-task deficit (ARD). In an effort(More)
The aim of the present study was to elucidate the contribution of the superior and posterior inferior cerebellum to adaptive improvement and aftereffects in a visuomotor adaptation task. Nine patients with ischemic lesions within the territory of the posterior inferior cerebellar artery (PICA), six patients with ischemic lesions within the territory of the(More)
In research on human motor skills, it is often desirable to manipulate proprioceptive feedback in order to determine its contribution towards subjects' performance. Here we evaluate an easy-to-use, non-invasive method to temporarily reduce proprioceptive responsiveness. Two physiotherapy vibrators contacted the distal end of the subjects' forearm on the(More)
Previous neuroimaging studies yielded different patterns of brain areas activated during sensorimotor adaptation, when sensory conflicts are introduced, e.g. by manipulating visual information. We propose that possible reasons might be the lack to control for adaptation or the change in motor performance. In consequence, it was not possible to distinguish(More)
It has been proposed in the past that adaptation to rotated visual feedback is based on directionally tuned modules. Here, we investigate whether adaptation depends on the number of modules that are concurrently activated. To disambiguate the number of modules and their spatial overlap, we decided to vary the number of target directions and their spacing(More)