Age-related differences of neural connectivity during mental rotation.

The purpose of the present study was to investigate age-related effects on functional brain networks during a mental rotation task. At behavioral level age-related cognitive deficits have been shown. Cognitive deficits in older adults are associated with structural decline, especially in frontal and parietal areas and in the corpus callosum.

The Effects of Slackline Balance Training on Postural Control in Older Adults.

The present study investigated whether slackline training enhances postural control in older adults. Twenty-four participants were randomized into an intervention and a control group. The intervention group received 6 weeks of slackline training, two times per week.

EEG coherence during mental rotation of letters, hands and scenes.

The purpose of the present study was to investigate differences in the electrocortical synchronization pattern during mental rotation of three different object categories as well as six different rotation angles. Therefore, event-related coherence of the electroencephalographic (EEG) activity between selective frontal and parietal electrode pairs of ten subjects was measured during the performance of a mental rotation task consisting of rotation of letters, hands and scenes. Statistical analysis showed an increased coherence of frontal and parietal electrode pairs for the condition LETTER in comparison to the other conditions in the alpha1- (8.

Concurrent adaptation to four different visual rotations.

The human sensorimotor system can concurrently adapt to two different distortions without interference when the distortions are cued by different contexts. We investigated whether this holds with four distortions as well. Subjects were exposed to an interlaced sequence of +30°, -30°, +60°, and -60° visuomotor rotations as the adaptation phase, cued by combinations of workspace location and by the arm used.

Proprioception plays a different role for sensorimotor adaptation to different distortions.

If proprioceptive feedback is degraded by agonist-antagonist muscle vibration, then adaptation to rotated vision remains intact while adaptation to a velocity-dependent force field worsens. Here we evaluate whether this differential effect of vibration is related to the physical nature of the distortion - visual versus mechanical - or to their kinematic coupling to the subjects' hand - velocity versus position dependent. Subjects adapted to a velocity-dependent visual distortion, to a position-dependent force, or to a velocity-dependent force; one half of the subjects adapted with, and the other half without agonist-antagonist vibration at the wrist, elbow, and shoulder.

Is sensorimotor adaptation to position- and velocity-dependent visual distortions based on distinct adaptive processes?

It is widely held that sensorimotor adaptation to different distortions is brought about by separate, distortion-specific processes which compete for the limited resources of short-term motor memory when they are activated in close temporal succession. Here we scrutinized this view by exposing participants sequentially to two distortions of equal or of opposite polarity, one proportional to the position, and the other to the velocity of their hand. We found movement errors to be largest in participants who were pre-adapted to a distortion of different type and opposite polarity, smaller in novice participants, and smaller still in participants who were pre-adapted to a distortion of different type and same polarity.

Concurrent adaptations of left and right arms to opposite visual distortions.

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 the time-course of adaptation, as well as aftereffects without visual feedback under uni- and bimanual conditions. Our data confirm that two adaptive states can co-exist in the sensorimotor system, one for each arm.

The effect of rest breaks on human sensorimotor adaptation.

We have studied the effect of rest breaks on sensorimotor adaptation to rotated visual feedback in a pointing task. Adaptive improvement was significantly poorer after 1-s breaks than after 5-40-s breaks, with no significant difference among the latter break durations. The benefit of >1-s breaks emerged soon after the onset of adaptation, and then remained steady throughout the adaptation, retention (next day), and persistence (no feedback) phases.