Abstract：
:Adaptation of motor control to weightlessness was studied during a 7-day spaceflight. The maintenance of control of upright posture was examined during a voluntary raising movement of the arm and during the voluntary raising on tiptoe. In order to evaluate the contribution of visual cues, three types of visual situations were examined: normal vision, central vision, and without vision. On the basis of cinematographic and mechanographic data, the postural perturbations consecutive to the movement of a body part in conditions of weightlessness were found to be similar to those observed on earth. However, in weightlessness, in contrast to the ground-based situation, erectness of posture was maintained primarily due to the predominant contraction of the ankle flexor muscles. The sequences of postural leg muscle activity associated with the arm or foot movement were well structured and varied slightly in the course of the flight. In addition, the initial posture, that is the erect posture before the movement was executed, changed throughout the flight from an exaggerated oblique position to a terrestrial standing position. Visual information was preponderant at the beginning of the space mission for the recalibration of other sensory cues affected by weightlessness. The findings are indicative of two types of adaptation of the central program of posture regulation to weightlessness: fast, short-term adaptation, characterized by a quasi-instantaneous redistribution of motor commands between ankle flexors and extensors (an "operative process") and slow, long-term adaptation, exemplified by the loss of anticipatory activation of certain muscles by the end of the flight (a "conservative process").
journal_name
Exp Brain Resjournal_title
Experimental brain researchauthors
Clément G,Gurfinkel VS,Lestienne F,Lipshits MI,Popov KEdoi
10.1007/BF00231132subject
Has Abstractpub_date
1984-01-01 00:00:00pages
61-72issue
1eissn
0014-4819issn
1432-1106journal_volume
57pub_type
杂志文章abstract：:Since the moment arms for the elbow-flexor muscles are longest at intermediate positions of the elbow and shorter at the extremes of the range of motion, it was expected that the elbow torque would also show a peak at an intermediate angle provided the activity of the flexor muscles remained constant. We measured the ...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：
更新日期：1985-01-01 00:00:00
abstract：:The repetition of muscle contractions is likely to generate fatigue which can provoke alterations of postural control. Regulatory mechanisms can be triggered to counteract these alterations. However, these mechanisms would occur only when fatigue is induced through voluntary (VOL) contractions and not with electricall...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-018-5418-9
更新日期：2019-02-01 00:00:00
abstract：:The efferent projections of the five histaminergic neuronal subgroups in the tuberomammillary nucleus to the medial preoptic area (MPO) and inferior colliculus (IC) were examined by immunocytochemistry with antihistidine decarboxylase (HDC) antibodies combined with retrograde axonal tracing with Fast Blue (FB). The te...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00228164
更新日期：1990-01-01 00:00:00
abstract：:The aim of the present study was to further investigate the contribution of primary muscle spindle feedback to proprioception and higher brain functions, such as movement trajectory recognition. For this purpose, complex illusory movements were evoked in subjects by applying patterns of muscle tendon vibration mimicki...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-005-0325-2
更新日期：2006-06-01 00:00:00
abstract：:Voluntary movements are preceded by a slow electrical potential of the brain (Bereitschafts-potential, BP) or readiness potential. The BP is accompanied by a magnetic field shift of similar time characteristics (Bereitschaftsmagnetfeld, BM). The BM preceding volitional right foot or toe movements was recorded from ant...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00237152
更新日期：1983-01-01 00:00:00
abstract：:When a target moves to a new location during a rapid aiming movement, the hand follows it, even when the participant intends not to. Pisella et al. (Nat Neurosci 3:729-736, 2000) claim that the posterior parietal cortex, in the dorsal visual stream, is responsible for this 'automatic pilot'. Here we study the limits o...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-007-0935-y
更新日期：2007-08-01 00:00:00
abstract：:In studies of human eye-head coordinated saccadic gaze shifts, different laboratories have found greatly different magnitudes of head movements for a given amplitude of gaze shift (head movement gain). The present study was conducted to examine why, and to quantify volitional head movements. Fixation/target lights wer...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00230391
更新日期：1992-01-01 00:00:00
abstract：:Human observers are experts at visual face recognition due to specialized visual mechanisms for face processing that evolve with perceptual expertize. Such expertize has long been attributed to the use of configural processing, enabled by fast, parallel information encoding of the visual information in the face. Here ...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-013-3463-y
更新日期：2013-05-01 00:00:00
abstract：:We applied vibration at various rates to the biceps tendon of a passive, restrained arm in normal human subjects and measured its effect on the perception of forearm position and the perception of forearm velocity. The disturbances of limb position perception and limb velocity perception depended on the vibration rate...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00269450
更新日期：1987-01-01 00:00:00
abstract：:Our aim was to describe the differences in the presence of trigger points (TrPs) in the shoulder muscles and to investigate the presence of mechanical hypersensitivity in patients with unilateral shoulder impingement and healthy controls. Twelve patients with strictly unilateral shoulder impingement and 10 matched con...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-010-2196-4
更新日期：2010-05-01 00:00:00
abstract：:Could task performance be constrained by our ability to fully engage necessary neural processing through effort of will? The StartReact phenomenon suggests that this might be the case, as voluntary reaction times are substantially reduced by loud sounds. Here, we show that loud auditory stimulation can also be associa...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-010-2474-1
更新日期：2011-01-01 00:00:00
abstract：:In order to assess the effects of [K+]o on the passive membrane properties of neostriatal neurons, the cable properties of these cells were determined at two extracellular potassium concentrations (6.25 and 3.0 mM). The effect of tetraethylammonium (TEA) on cable properties was also studied at 6.25 [K+]o. At 6.25 mM [...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00250260
更新日期：1988-01-01 00:00:00
abstract：:We examined the distribution of labeled neurons in the parabigeminal nucleus of the monkey following injections of retrograde fluorescent tracers into the superior colliculus. The extent of the visual field representation included in the injection site was assessed from the location of labeled cells in striate cortex....
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00230521
更新日期：1991-01-01 00:00:00
abstract：:Movement sequences such as typing or tapping display important interactions among finger movements arising from anticipatory motion (preparing for upcoming events) and coupling (non-independence among fingers). We examined pianists' finger tapping for the influence of cognitive chunking processes and biomechanical cou...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-006-0760-8
更新日期：2007-04-01 00:00:00
abstract：:The latency of eye movements is influenced by the fixation task; when the fixation stimulus is switched off before the target presentation (gap paradigm) the latency becomes short and express movements occur. In contrast, when the fixation stimulus remains on when the target appears (overlap paradigm), eye movement la...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-005-2214-0
更新日期：2005-07-01 00:00:00
abstract：:Decision times involved in selecting visual targets with saccadic eye movements in rhesus monkeys were studied for three tasks in which single targets, paired targets with varied asynchronies, and multiple targets requiring a discrimination were presented. Probability of target choice in the paired-target task was str...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-003-1653-8
更新日期：2004-01-01 00:00:00
abstract：:We compared pursuit responses to 2D target motion in three separate conditions: predictable, randomised and randomised with timing cues. The target moved on a continuous quadrilateral path in which right-angle direction changes allowed anticipatory eye acceleration and deceleration in orthogonal axes to be assessed. R...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-014-4164-x
更新日期：2015-03-01 00:00:00
abstract：:Ideal grasping movements should maintain an appropriate probability of success, while controlling movement-related costs, in the presence of varying visual (and motor) uncertainty. It is often assumed that the probability of errors is managed by adjusting a margin for error in hand opening (e.g., opening the hand wide...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-019-05489-z
更新日期：2019-04-01 00:00:00
abstract：:The overlap of dominant tremor frequencies and similarly amplified tremor observed for Parkinson's disease (PD) and essential tremor (ET) means differentiating between these pathologies is often difficult. As tremor exhibits non-linear properties, employing both linear and non-linear analyses may help distinguish betw...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-017-4924-5
更新日期：2017-06-01 00:00:00
abstract：:Transcranial direct current stimulation (tDCS) induces cortical excitability changes in animals and humans that can last beyond the duration of stimulation. Preliminary evidence suggests that tDCS may have an analgesic effect; however, the timing of these effects, especially when associated with consecutive sessions o...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-012-3149-x
更新日期：2012-08-01 00:00:00
abstract：:When reaches are performed toward target objects, the presence of other non-target objects influences kinematic parameters of the reach. A typical observation has been that non-targets positioned ipsilaterally to the acting limb interfere more with the trajectory of the hand than contralateral non-targets. Here, we in...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-013-3615-0
更新日期：2013-09-01 00:00:00
abstract：:When two hands require different information in bimanual asymmetric movements, interference can occur via callosal connections and ipsilateral corticospinal pathways. This interference could potentially work as a cost-effective measure in symmetric movements, allowing the same information to be commonly available to b...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-010-2244-0
更新日期：2010-06-01 00:00:00
abstract：:The purpose of the present work was to characterize calcium responses of brain-capillary endothelial cells (BCEC), the cells forming the blood-brain barrier, to chemical, hyperosmolar and mechanical stimulation. Confluent BCEC cultures were grown from capillary fragments isolated from rat cerebral cortex. Intracellula...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s002210050755
更新日期：1999-06-01 00:00:00
abstract：:The aim of this study was to examine coherence between surface electromyographic (EMG) signals from two index finger flexor muscles, the first dorsal interosseous (FDI) and flexor digitorum superficialis (FDS), during and immediately following sustained, fatiguing isometric contraction. Coherence was observed between ...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-009-2110-0
更新日期：2010-04-01 00:00:00
abstract：:The adaptation and habituation characteristics produced by the repeated presentation of a moving visual stimulus were studied in single cells in the pigeon's optic tectum. Units located near the surface in the stratum opticum showed little adaptation. However, cells located in deeper layers exhibited varying rates and...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00235509
更新日期：1977-03-30 00:00:00
abstract：:The calcium content of mitochondria isolated from the Torpedo electric organ was determined by atomic absorption spectroscopy. The mitochondrial fraction was found to contain 830 ng-atom Ca/mg protein. For comparison a fraction of isolated nerve endings contained 250 ng-atom Ca/mg protein. When tissue was continuously...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00237520
更新日期：1980-01-01 00:00:00
abstract：:A simple model of the vestibuloocular reflex and the optokinetic system was used to simulate recent data on visual and vestibular responses of neurons in the vestibular nucleus. Contrary to a previous interpretation, the results support the hypothesis that the optokinetic and semicircular canal signals are combined si...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00237269
更新日期：1977-11-24 00:00:00
abstract：:Is it possible to learn to perform a motor sequence without awareness of the sequence? In two experiments, we presented participants with the most elementary sequence: an alternation between two options. We used a double-step pointing task in which the final position of the target alternated between two quite similar ...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-016-4566-z
更新日期：2016-06-01 00:00:00
abstract：:A syntactic and a semantic task were performed by German-speaking healthy subjects and aphasics with lesions in the dominant left hemisphere. In both tasks, pictures of objects were presented that had to be classified by pressing buttons. The classification was into grammatical gender in the syntactic task (masculine ...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s002210100794
更新日期：2001-09-01 00:00:00
abstract：:Research on joint attention has addressed both the effects of gaze following and the ability to share representations. It is largely unknown, however, whether sharing attention also affects the perceptual processing of jointly attended objects. This study tested whether attending to stimuli with another person from op...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-011-2625-z
更新日期：2011-06-01 00:00:00
