SEARCH · PubMed Health

Results for “sensorimotor function”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49Linked to original sources

PubMed1997

Motor and sensory dysfunctions in children with mental retardation and epilepsy.

The aim of this study was to assess motor and sensory functions in a population-based series of 88 mentally retarded children with epilepsy. A new standardized physiotherapy protocol was developed for the heterogeneous population of children with epilepsy; the Cailler-Azusa scale was also found to be useful. For children with cerebral palsy, the gross motor function measure was used. Sensorimotor impairments, resulting in disabilities and handicap, were found to be very common but often overlooked and neglected. Sensorimotor dysfunctions need to be identified in order to provide rational training, understanding and care to children with epilepsy and mental retardation.

Cerebral Palsy↗

PubMed2006

Effect of age and sex on maturation of sensory systems and balance control.

Maintenance of postural balance requires an active sensorimotor control system. Current data are limited and sometimes conflicting regarding the influence of the proprioceptive, visual, and vestibular afferent systems on posture control in children. This study investigated the development of sensory organization according to each sensory component in relation to age and sex. A total of 140 children (70 males, 70 females; mean age 10y [SD 4y]; age range 3y 5mo-16y 2mo) and 20 adults (10 males, 10 females; mean age 30y 6mo [SD 8y 4mo]; age range 17y 2mo-49y 1mo) were examined using the Sensory Organization Test. Participants were tested in three visual conditions (eyes open, blindfolded, and sway-referenced visual enclosure) while standing on either a fixed or a sway-referenced force platform. Mean equilibrium scores for the six balance conditions showed rapid increases and maturation ceiling levels for age-related development of the sensorimotor control system. Proprioceptive function seemed to mature at 3 to 4 years of age. Visual and vestibular afferent systems reached adult level at 15 to 16 years of age, revealing differences between young males and females. Characterizing balance impairments can contribute to the diagnostic evaluation of neuromotor disorders.

Adolescent↗

PubMedDate not supplied

Somatosensory evoked potentials during natural and learning rearrangements of posture accompanied by limb elevation in dogs.

Changes in the functional state of the sensorimotor cortex associated with reorganization of the natural pattern of postural rearrangement before limb elevation (the "diagonal" patten and of an artificial rearrangement (the "unilateral" pattern) were studied in dogs. The state of cortical structures on postural rearrangement was assessed in terms of the pattern of somatosensory evoked potentials produced in response to stimulation of the forelimb during postural preparation of the animal for elevating the hindlimb (acquired avoidance response to a sound signal). Evoked potentials during the natural postural preparation (the "diagonal" pattern) were compared with those during the altered pattern of postural preparation (the "unilateral" pattern), this preparation taking place prior to elevation of the limb. Controls consisted of evoked potentials in the resting state. Decreases were seen in the latencies and amplitudes of most components of evoked potentials during postural rearrangement. In general, changes in evoked potentials were less marked in the "unilateral" pattern than in the "diagonal" pattern, though the differences were significant only for the amplitude of the first negative component. Changes in evoked potentials were similar regardless of whether the supporting forces of the limb to which the test stimulus was applied increased or decreased during postural rearrangement. It is suggested that differences in evoked potentials may reflect changes in the interaction between neuronal populations within the sensorimotor cortex during reorganization of the pattern of postural rearrangement associated with learning.

Animals↗

PubMed1999

Children with autism experience problems with both objects and people.

Kanner (1943), in his classic account, described autism as a specific impairment in interpersonal relations which leaves the child's uses of objects relatively unaffected. This combination of the difficulties in relating to people and the supposedly "excellent" relations to objects figures centrally within many of the current theories of autism, which have had relatively little to say on the question of object use. This paper draws attention to evidence of widespread impairments in relating to objects, not only in interpersonal aspects of object use but also in early sensorimotor exploration and the functional and conventional uses of objects. In stressing these problems with objects, our purpose is not to downplay the social dimension of autism, but rather to highlight the reciprocal nature of the interactions between the child, other people, and objects. Given the evidence that other people play an important role in introducing objects to children, we propose that an impairment in interpersonal relations should itself lead us to expect corresponding disruption in the autistic child's use of objects. Conversely, an unusual use of objects is likely to manifest itself in disturbances in relating to other people, given the importance of a shared understanding and use of objects in facilitating interaction.

Autistic Disorder↗

PubMed1997

Intellectual functioning in old and very old age: cross-sectional results from the Berlin Aging Study.

This study documents age trends, interrelations, and correlates of intellectual abilities in old and very old age (70-103 years) from the Berlin Aging Study (N = 516). Fourteen tests were used to assess 5 abilities: reasoning, memory, and perceptual speed from the mechanic (broad fluid) domain and knowledge and fluency from the pragmatic (broad crystallized) domain. Intellectual abilities had negative linear age relations, with more pronounced age reductions in mechanic than in pragmatic abilities. Interrelations among intellectual abilities were highly positive and did not follow the mechanic-pragmatic distinction. Sociobiographical indicators were less closely linked to intellectual functioning than sensory-sensorimotor variables, which predicted 59% of the total reliable variance in general intelligence. Results suggest that aging-induced biological factors are a prominent source of individual differences in intelligence in old and very old age.

Aged↗

PubMed1983

The effect of stimulus variation on lexical learning.

At some early stage in a child's development of the comprehension and production of language, he/she must recognize that single words correspond to referents in the environment. How to best present the critical aspects of the environment to which a verbal label is attached is not entirely known. For language-impaired children it is important to know how to highlight this relationship between linguistic and nonlinguistic cues so that therapy will be most effective. To examine how language-impaired children best learn single word lexical items, nouns and verbs were taught expressively through two modes of stimulus presentation thought to highlight the nonlinguistic environment: object manipulation and picture identification. The efficacy of these two treatment conditions was assessed with four children functioning at Piaget's sensorimotor period of development by using a single subject, alternating treatments design. The results indicated individual variation in learning strategies. Two of the children learned more single words (nouns and verbs) in the object manipulation condition. One child learned equally well in both conditions and the fourth child learned best in the picture identification condition. Variables accounting for the individual variation are discussed.

Child, Preschool↗

PubMed2001

The norepinephrine precursor L-threo-3,4-dihydroxyphenylserine facilitates motor recovery in chronic stroke patients.

L-threo-3, 4-dihydroxyphenylserine (L-DOPS) is a precursor of norepinephrine. We reported that administration of L-DOPS to rats with ablation of the right sensorimotor cortex results in functional recovery from deficits in beam-walking performance. We al so reported that improvement in Fugl-Meyer Score (FMS) was significantly higher in an L-DOPS-treated group of chronic neurologically stable stroke patients than in a control group for 2 days. In the present study, 27 patients who had suffered from stroke more than one month previously and had exhibited no improvement in neurological deficits for at least one week were administered 300mg/day L-DOPS for 28 days with rehabilitation. FMS improved by 4.4 points (P< 0.001), 10m gait time was shortened by 16% (P< 0.001) and the cerebral blood flow of the lesion was increased (P< 0.03), after 28 days of drug administration. These findings suggest that L-DOPS is effective in restoring neurological deficit, which does not usually recover when only treated with rehabilitation therapy.

Adult↗

PubMed1995

Age effects on reflex and postural responses to propriomuscular inputs generated by tendon vibration.

The effects of aging on two sensorimotor levels of propriomuscular function were investigated in a young (20- to 44-year-old) and an elderly (60- to 86-year-old) population by eliciting segmental reflex and postural responses via the same muscle spindle inflow generated by applying the same pattern of tendon vibration. The latency and amplitude of the reflex responses to vibration (tonic vibration reflex) of the biceps and triceps brachii did not depend on the subjects' age. No major age-related changes were observed in the deep reflexes of the lower limbs. The postural responses to the same vibratory stimulation applied to both the soleus or the tibialis anterior muscles (vibration-induced falling) did not show any changes in latency depending on either age or the visual conditions, whereas the intensity of these responses decreased both with age and when the use of vision was possible. Our results suggest that the two levels at which the same propriomuscular messages were processed are differentially affected by aging. The lower reflex level does not undergo any noticeable impairment, whereas the higher postural control level deteriorates in the elderly, which might be partly responsible for the balance problems which tend to occur more frequently with advancing age.

Adult↗

PubMed2001

Choice stepping reaction time: a composite measure of falls risk in older people.

BACKGROUND: This study investigated the neuropsychological, sensorimotor, speed, and balance contributions to a new test of choice stepping reaction time (CSRT) and determined whether this new test is an important predictor of falls in older people. METHODS: A total of 477 retirement-village residents aged 62 to 95 years (mean +/- SD, 79.2 +/- 6.2 years) took the CSRT test, which required them to step onto one of four panels that were illuminated in a random order. The subjects also took tests that measured neuropsychological, sensorimotor, speed, and balance function. RESULTS: Multiple regression analysis revealed that poor performance in Part B of the Trail Making Test (a neuropsychological test) and impaired quadriceps strength, simple reaction time, sway with eyes open on a compliant surface, and maximal balance range were the best predictors of increased CSRTs (multiple r(2) =.45). Subjects with a history of falls had significantly increased CSRTs compared with nonfallers (1322 +/- 331 milliseconds and 1168 +/- 203 milliseconds, respectively). Impaired CSRT was a significant and independent predictor of falls, as were two complementary sensory measures (visual contrast sensitivity and lower limb proprioception). Of these measures, CSRT was the most important in predicting falls. Furthermore, the inclusion of CSRT in the model excluded measures of strength, central processing speed, and balance, because these could not provide nonredundant information for the prediction of falls. CONCLUSIONS: This study identifies a new test that provides a composite measure of falls risk in older people and elucidates the relative importance of specific physiological and neuropsychological systems in the initiation of fast and appropriate step responses.

Accidental Falls↗

PubMed1992

A behavioral study of bilateral middle cerebral artery hemorrhagic ischemia in rats.

The middle cerebral artery was severed bilaterally (bMCA) in adult rats, and controls experienced sham operations. Tactile sensorimotor and gross locomotor functions, measured by the tape test and a rod walking test, were initially impaired in the injured animals. However, these deficits had resolved within 9 and 30 days respectively. The animals were trained in a multiple T water maze task to find the location of a hidden escape platform at the rate of one trial per day for 30 days. Analyses of the number of errors committed and latency to find the escape platform revealed that the bMCA injured rats suffered deficient reference memory, but no decline in working memory. These data support further the use of the bMCA preparation as a model of stroke.

Animals↗

PubMed1979

Orthostatic postural activity disorders recorded by statokinesimeter in post-concussional syndromes: oculomoter aspect.

The purpose of this paper is to emphasize the influence of the mesencephalic oculomotor system regulation on orthostatic postural regulation. The body at rest is never immobile but it swings continuosly. The amplitudes and the frequencies of body sway give an indication of the function of the different sensorimotor loops which are involved in body balance. An apparatus, the statokinesimeter, allows us to record these motions by means of displacement of the body's centre of gravity with respect to the centre of the basis. In the case of head or cervical injuries, the brain stem is often implicated giving a partial nuclear unilateral lesion of the III nucleus; double vision of a few degrees with picture separation of never more than 4 degrees occurs. A compensory deviation of the head follows. A conflict between afferents from the III, IV, VI, VII, XI and supraspinal nuclei occurs. The amplitude and the frequency of the body sway change. A form of treatment is proposed for the 'pseudo-vertigo' of post-concussional syndrome.

Brain Concussion↗

PubMed1989

Intrafascicular multi-unit recordings from the human infra-orbital nerve.

Intrafascicular micro-electrode recordings were made from the human infra-orbital nerve close to the infra-orbital foramen. The fascicular organization was studied and multi-unit activity from low-threshold mechanoreceptive afferents was recorded during tactile stimuli, vibration and facial movements. Attempts were also made to record C-fibre activity. Innervation zones corresponding to 66 fascicles were mapped with tactile stimuli on facial hairy skin and the red zone of the lip. Most of these fields were located on the upper lip, where they overlapped, indicating a high innervation density. The fields had a median size of 3.8 cm2. Skin indentation evoked dynamic on- and off-responses and a much less pronounced static discharge. The afferent double-peaked responses to an oscillating probe applied to the peri-oral region induced similar grouping of the EMG activity during sustained lip protrusion. Contraction of facial muscles and stretching of the skin evoked on- and off-responses, whereas the static discharge was less pronounced, especially during sustained stretching. The dynamic sensitivity to minor variations in contraction and stretching was high, and during normal facial movements, as in speech, there was a barrage of impulses originating from mechanoreceptors within large facial areas. Functional implications of these sensorimotor interactions are discussed. Sympathetic C-fibre activity, frequently seen in recordings from the supra-orbital nerve, was never encountered in the infra-orbital nerve recordings, indicating a lack of such fibres. Failure to detect afferent C-fibre activity could be explained by methodological difficulties.

Adult↗

PubMed2001

Sensory disturbances after focal extirpations of the human "motor" cortex.

From the late 1800s until approximately the middle of the 20th century, neurosurgeons made discrete motor cortex lesions in humans in attempts to reduce or eliminate a variety of involuntary movements, resulting mainly from epilepsy. In some cases, the neurosurgeons tested and recorded their patients' ability to perform various movements and to perceive various types of sensory stimuli after the operation. Although these studies have been largely forgotten, they have an immense advantage over primate lesion studies for understanding the function of the motor cortex because the patients were able to attempt to perform complex movements upon request, and to describe their perceptions of cutaneous stimuli, including integrated sensations (e.g., recognition of objects by palpation alone). We provide here a table containing the results of these studies pertaining to sensory deficits. The most consistent and persistent sensory deficits reported relate to object recognition and position sense. This finding is in keeping with recent electrophysiological studies in primates. Our analysis suggests that the "motor" cortex serves important sensory functions; hence, the term sensorimotor cortex, remains appropriate for the primate precentral (and postcentral) cortex.

Epilepsies, Partial↗

PubMed2004

Dynamics of everyday life: rigorous modular modeling in neurobiology based on Bloch's dynamical theorem.

Natural, everyday sensorimotor behaviors, such as rising from sitting, typically have an intrinsic organization of several levels of analysis. Taking this intrinsic organization as key to understanding neural dynamics is neither a top-down nor a bottom-up approach, but rather a meshing of multiple centers and levels of analysis. Motor control requires body dynamics that are consistent with physical dynamics, besides the more microscopic levels of neural dynamics. The dynamics of separate movements have been investigated as if the ends can be capped off, separated from the rest of the individual's life. Is this dynamically correct? Even chaotic behavior is deterministic. However, the mathematics of nonlinear oscillations is not all of dynamics. This paper relates Bloch's dynamical theorem to the modular, conditional approach to sensorimotor and other neural functioning. Bloch's dynamical theorem lays a foundation for the piecewise study of structurally accurate dynamics in theoretical neurobiology. Piecewise studies can be used as a modeling option complementary to the methods of nonlinear oscillator dynamics. By applying Bloch's theorem, dynamics of movements analyzed piecewise can be extended into a smooth flow on any manifold, either as a whole or conditionally. Conditional dynamics makes dynamical modeling options explicit, often depending on what variables the organism can control, and allows one to take different modeling options at different junctures in analyzing the same phenomenon. For example, this approach allows the study of complex motor control problems to be reduced to modular constructions using singularities and flow lines. Dynamical contingencies are expressed using the mathematics of ordered structures. This paper presents Bloch's dynamical theorem and its relevance to model construction in theoretical neurobiology. Specific examples, integrated into physiological and behavioral context, are cited from the literature.

Models, Neurological↗

PubMed2006

Sensorimotor training in a virtual reality environment: does it improve functional recovery poststroke?

OBJECTIVE: To investigate the effectiveness of computerized virtual reality (VR) training of the hemiparetic hand of patients poststroke using a system that provides repetitive motor reeducation and skill reacquisition. METHODS: Eight subjects in the chronic phase poststroke participated in a 3-week program using their hemiparetic hand in a series of interactive computer games for 13 days of training, weekend breaks, and pretests and posttests. Each subject trained for about 2 to 2.5 h per day. Outcome measures consisted of changes in the computerized measures of thumb and finger range of motion, thumb and finger velocity, fractionation (the ability to move fingers independently), thumb and finger strength, the Jebsen Test of Hand Function, and a Kinematic reach to grasp test. RESULTS: Subjects as a group improved in fractionation of the fingers, thumb and finger range of motion, and thumb and finger speed, retaining those gains at the 1-week retention test. Transfer of these improvements was demonstrated through changes in the Jebsen Test of Hand Function and a decrease after the therapy in the overall time from hand peak velocity to the moment when an object was lifted from the table. CONCLUSIONS: It is difficult in current service delivery models to provide the intensity of practice that appears to be needed to effect neural reorganization and functional changes poststroke. Computerized exercise systems may be a way to maximize both the patients' and the clinicians' time. The data in this study add support to the proposal to explore novel technologies for incorporation into current practice.

Aged↗

PubMed1995

Event-related coherence during finger movement: a pilot study.

Dynamic functional coupling between contralateral sensorimotor and supplementary motor areas during unilateral finger movements is studied using event-related coherence analysis. It is demonstrated in 3 subjects that the intrinsic rhythm of the sensorimotor area (mu rhythm) is phase coupled to intrinsic rhythmic activity of the supplementary motor area during rest. With preparation and execution of discrete, unilateral finger movements, these intrinsic rhythms are desynchronized due to activation of each of the local cortical networks, and the degree of synchrony or phase consistency between these rhythms decreases.

Brain Mapping↗

PubMed2005

Bidirectional activity-dependent plasticity at corticostriatal synapses.

Corticostriatal projections originate from the entire cerebral cortex and provide the major source of glutamatergic inputs to the basal ganglia. Despite the importance of corticostriatal connections in sensorimotor learning and cognitive functions, plasticity forms at these synapses remain strongly debated. Using a corticostriatal slice preserving the connections between the somatosensory cortex and the target striatal cells, we report the induction of both non-Hebbian and Hebbian forms of long-term potentiation (LTP) and long-term depression (LTD) on striatal output neurons (SONs). LTP and LTD can be induced selectively by different stimulation patterns (high-frequency trains vs low-frequency pulses) and were evoked with similar efficiency in non-Hebbian and Hebbian modes. Combination of LTP-LTD and LTD-LTP sequences revealed that bidirectional plasticity occurs at the same SONs and provides efficient homeostatic mechanisms leading to a resetting of corticostriatal synapses avoiding synaptic saturation. The effect of temporal relationship between cortical stimulation and SON activity was assessed using spike-timing-dependent plasticity (STDP) protocols. An LTP was observed when an action potential was triggered in the striatal neuron before the cortical stimulus, and, conversely, an LTD was induced when the striatal neuron discharge was triggered after the cortical stimulation. Such STDP was reversed when compared with those described so far in other mammalian brain structures. This mechanism may be essential for the role of the striatum in learning of motor sequences in which sensory and motor events are associated in a precise time sequence.

Animals↗

PubMed1993

An occupational therapy perspective in the treatment of multiple personality disorder.

Adult persons with multiple personality disorder have survived a traumatic past. After diagnosis and the initiation of psychotherapy, they frequently face a long and arduous treatment process. During this time, intense emotions and memories are retrieved that can disrupt functional life skills in an already disjointed life. The stresses of life combine with therapeutic issues to perpetuate the dissociation that interrupts functional performance. The original traumas occurred when the child was functioning primarily at a sensorimotor level. Occupational therapy can identify sensorimotor activities that provide a focal point of control to reduce stress during the therapeutic process and to develop new life skills.

Activities of Daily Living↗