[Complex forms of the behavior of the anthropoid, based on the formation of distant visual temporary connectors].
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Tests of interhemispheric disconnection including visual, somesthetic, kinesthetic, auditory, and complex motor functions were performed on seven patients with chronic epilepsy who had undergone partial surgical section of the corpus callosum, verified by magnetic resonance imaging. Two patients with only one third of the splenium remaining demonstrated disconnection syndromes involving all modalities except vision, which was completely intact. Five patients had lesions involving the rostrum and the anterior two thirds to four fifths of the body of the callosum, with the splenium spared. They demonstrated little evidence of disconnection in the modalities indicated, except for left ear suppression on a dichotic listening task and partial somatosensory disruption in some cases. These results emphasize the importance of the posterior corpus callosum for interhemispheric sensory and sensorimotor transfer, although some discrepancies between current behavioral data and previous anatomic findings remain.
OBJECTIVE: To determine whether there is a complex sensory disturbance that may be contributing to the motor deficit in patients with Parkinson disease. DESIGN: Comparison of performance by patients and healthy, age- and sex-matched subjects in tests of various sensory functions. SETTING: The Center for Human Performance and Testing at a university hospital and research center. PARTICIPANTS: Ten subjects with Parkinson disease and 10 control subjects matched for age and sex. MAIN OUTCOME MEASURE: Performance on 4 subjects of the Sensory Integration and Praxis Test: finger identification, graphesthesia, localization of tactile stimuli, and kinesthesia. RESULTS: Data were analyzed using paired t tests for ratio data and the paired Wilcoxon test for ordinal data. Patients with Parkinson disease performed significantly worse (P = .001) than the control patients on the test of kinesthesia. There were no significant differences between the 2 groups on the other subtests. CONCLUSIONS: Without visual guidance, patients with Parkinson disease had more difficulty in perceiving the extent of a movement made to a target away from the body, a task requiring reliance on proprioceptive feedback. Parkinsonian patients had no more difficulty than controls in making movements to a target on the surface of the body when they could use tactile sensations. Movement difficulties in patients with Parkinson disease may relate in part to a decrease in proprioception. Activities that enhance kinesthetic awareness may be an important adjunct to the treatment of these patients.
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A patient with a 62-year history of Gilles de la Tourette syndrome describes 35 years of self-observation of the subjective events that precede, accompany, and follow the occurrence of symptomatic movements and sounds. Bodily sites become sensitized, and the movements (however bizarre) are intentional acts aimed at satisfying and eliminating unfulfilled sensations and urges. Sensory impressions may be projected onto other persons, objects, or imagined objects; these phantom sensations also demand discharge through actions. With vigilance and self-observation, barely emergent sensations can be recognized and controlled temporarily through substitution or extinction. The need to cope with rampant sensations and their consequences on one hand and current affairs on the other creates a dual citizenship within the person.
The better understanding of the systems of the human body and their specific functions has led to minimally invasive and microsurgical procedures being carried out on an ever smaller scale. New therapies will require precision of 10 microm or better, which will only be achievable with robotic teleoperators. Experience with existing robot-assisted surgery systems shows that the human-machine interface is a critical component for acceptance of this technology, but no universally satisfactory interface has yet been found. Therefore, this article investigates a new concept based on kinesthetic motion feedback and presents details of the implementation of a first prototype.
An experimental subject sequentially receives different levels of a stimulus, and data are recorded on response or non-response to the stimulus. To ensure that the subject cannot predict the next stimulus level based on previous stimulus levels, a randomized design, based on a generalized Pólya urn model, is used to allocate the stimulus levels. The goal of the experiment is to elicit information efficiently about the relationship between stimulus level and response (either for an individual subject or a group of independent subjects), by estimating quantiles of the stimulus-response curve. Our design allocates stimulus levels unimodally and symmetrically around the unknown median of the stimulus-response curve. We discuss estimation under a broad family of distributions and also fully discuss design issues and options. This design was used for an experiment in neurophysiology in humans to estimate the timing of onset of kinesthetic stimuli. Such psychophysical studies can increase our understanding of normal and pathological function. We present data from that experiment.
We compared the kinetics of brachiation to bipedal walking and running. Gibbons use pectoral limbs in continuous contact with their overhead support at slow speeds, but exhibit aerial phases (or ricochetal brachiation) at faster speeds. This basic interaction between limb and support suggests some analogy to walking and running. We quantified the forces in three axes and torque about the vertical axis generated by a brachiating White-handed gibbon (Hylobates lar) and compared them with bipedal locomotion. Handholds oriented perpendicular to the direction of travel (as in ladder rungs) were spaced 0.80, 1.20, 1.60, 1.72, 1.95, and 2.25 m apart. The gibbon proportionally matched forward velocity to stride length. Handhold reaction forces resembled ground reaction forces of running humans except that the order of horizontal braking and propulsion were reversed. Peak vertical forces in brachiation increased with speed as in bipedal locomotion. In contrast to bipedalism, however, peak horizontal forces changed little with speed. Gait transition occurred within the same relative velocity range as the walk-run transition in bipeds (Froude number = 0.3-0.6). We oriented handholds parallel to the direction of travel (as in a continuous pole) at 0.80 and 1.60 m spacings. In ricochetal brachiation, the gibbon generated greater torque with handholds oriented perpendicular as opposed to parallel to the direction of travel. Handhold orientation did not affect peak forces. The similarities and differences between brachiation and bipedalism offer insight into the ubiquity of mechanical principles guiding all limbed locomotion and the distinctiveness of brachiation as a unique mode of locomotion.
Time trends are present in many sequential experiments. Adaptive designs use accruing data to select future design points. It has been observed that the presence of time trends in adaptive designs can bias results of the study. We propose one method of dealing with time trends in analysing adaptive designs. The method, relevance weighted likelihood, weights individual components of the likelihood differently. Consequently, one can downweight earlier data if there is a clear time trend that converges at some point in the study. We apply this methodology to a data set from an adaptive design in neurophysiology. We find that the method is robust and useful in getting more precise estimates of an individual subject's median response.
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BACKGROUND: This section is under preparation and will be included in the next issue. OBJECTIVES: Main question: in preterm infants with apnea, does the use of kinesthetic stimulation lead to clinically important reductions in clinical apnea and bradycardia (>50% reduction in number of episodes), use of mechanical ventilation (IPPV) or continuous positive airways pressure (CPAP), and neurodevelopmental disability, without clinically important side effects. SEARCH STRATEGY: The standard search strategy of the Neonatal Review Group was used. This included searches of the Oxford Database of Perinatal Trials, Cochrane Controlled Trials Register, MEDLINE, previous reviews including cross references, abstracts, conferences, symposia proceedings, expert informants, and journal handsearching mainly in the English language. SELECTION CRITERIA: All trials using random or quasi-random patient allocation in which kinesthetic stimulation in preterm infants was compared to placebo or no treatment for apnea of prematurity were included. DATA COLLECTION AND ANALYSIS: Standard methods of the Cochrane Collaboration and its Neonatal Review Group were used with separate evaluation of trial quality, data extraction by both authors and synthesis of data using relative risk and weighted mean difference. As all three trials were crossover trials, the data were extracted from all exposure periods and combined where appropriate. Measures of severity of apnea as well as the response to treatment were consistent with an evaluation of 'clinical apnea', as defined by the American Academy of Pediatrics (Nelson 1978). MAIN RESULTS: Three crossover studies (Korner 1978, Tuck 1982 and Jirapaet 1993) were identified that compared a form of kinesthetic stimulation to control for the treatment of apnea of prematurity. Clinically significant apnea: None of the three studies showed an important reduction (>50%) in clinical apnea. Using a lower threshold (>25%), the study by Korner 1978 found less apnea and bradycardia in infants receiving kinesthetic stimulation. Tuck 1982 demonstrated reductions in the frequencies of apneas (> 12 seconds) associated with bradycardia (< 100 bpm), apneas associated with hypoxia (TcP02 < 50 mmHg), and apneas requiring stimulation in infants on the rocking bed. Individual patient data were not available from the author to determine if there was an important reduction in clinical apnea. No outcome could be extracted from the study by Jirapaet 1993 that was consistent with the definition of clinically important apnea. Other events: No significant differences were found in the incidence of infants requiring resuscitation, IPPV, CPAP or respiratory stimulants whilst receiving treatment. Adverse events such as death, intraventricular hemorrhage and neurodevelopmental follow up were not reported. REVIEWER'S CONCLUSIONS: There is insufficient evidence to recommend kinesthetic stimulation as treatment for clinically significant apnea of prematurity. Previous reviews have suggested that kinesthetic stimulation is not effective at preventing apnea of prematurity (Henderson-Smart and Osborn 1998) and is not as effective as theophylline at treating clinically significant apnea of prematurity (Osborn and Henderson-Smart 1998).