scholarly journals Perceived Horizontal Body Position in Healthy and Paraplegic Subjects: Effect of Centrifugation

2003 ◽  
Vol 90 (5) ◽  
pp. 2973-2977 ◽  
Author(s):  
T. Jarchow ◽  
M. Wirz ◽  
T. Haslwanter ◽  
V. Dietz ◽  
D. Straumann
Keyword(s):  
Healthy Subjects ◽  
Visual Cues ◽  
Body Position ◽  
Vertical Axis ◽  
The Body ◽  
The Earth ◽  
Vestibular Information ◽  
The Individual ◽  
And Shifts ◽  
Stimulation Of

The perception of body position is mainly mediated by otolith information and visual cues. It has been shown, however, that proprioceptive sources are also involved. To distinguish between the contributions of the vestibular and nonvisual extra-vestibular information to graviception, we tested the effects of a stimulus that leaves the vestibular input unchanged but modifies the information from sense organs located more caudal along the trunk. This was achieved by bringing subjects into a horizontal ear-down position and rotating them around an earth-vertical axis that coincided with the interaural axis. In this paradigm, through centrifugal force, the stimulation of the vestibular and the putative extravestibular graviceptive organs in the body becomes dissociated. Healthy subjects ( n = 14) and paraplegic patients with lesions between T4 and T8 ( n = 7) adjusted themselves to the perceived horizontal right-ear down body position under two conditions: one with constant velocity rotation (ROT, velocity =120°/s) around the earth-vertical axis of the turntable, and one without rotation (BASE). Among healthy subjects, the individual differences between BASE and ROT varied widely in both the feet-up or feet-down direction. In contrast, adjustments in paraplegic patients during ROT were always in the feet-down direction compared with BASE. A model with two extravestibular graviceptive sensors could explain our results: one sensor is located rostral to T4, and the other is caudal to T8. A load on the rostral graviceptor is interpreted as a tilt of the body in the feet-up direction and shifts the adjustments of perceived body position feet-down; a load on the caudal receptor is interpreted as a tilt in the feet-down direction and shifts the perceived body position feet-up. During ROT, healthy subjects solve the discrepant inputs of both extravestibular graviceptors in a highly variable manner, while paraplegic subjects show less variability because they are restricted to only the rostral graviceptor.

Memoirs: The Neuro-Muscular Mechanism of the Gill of Pecten

1930 ◽  
Vol s2-73 (291) ◽  
pp. 365-392
Author(s):  
S. B. SETNA
Keyword(s):  
Feeding Habits ◽  
Adductor Muscle ◽  
The Body ◽  
Muscle Fibres ◽  
Direct Stimulation ◽  
Gill Filaments ◽  
Lateral Extent ◽  
Branchial Nerve ◽  
The Individual ◽  
Stimulation Of

Experimental. 1. The contraction of the adductor-muscle which follows stimulation of the palial nerve is preceded by a marked contraction of the ctenidial axis, so that the gill contracts before the adductor-muscle becomes active. This movement of the ctenidium is abolished if the main branchial nerve is cut near its origin. 2. The gills of Pecten possess a neuromuscular mechanism which is to some extent independent of the rest of the body, so that excised gills when stimulated react in the same way as an attached gill. 3. The lamellae of the gill possess two distinct types of movement. (a) When the surface of the gill is stimulated by contact with a glass rod or by carmine particles, the frontal surfaces of the two lamellae approach each other; the movement very often being executed by the lamella which is not actually being stimulated. The lateral extent of these movements (concertina movements) is roughly proportional to the intensity of the stimulus. Such movements normally appear to transfer the bulk of the material on to the mantle. Separation of the main branchial nerve abolishes these movements. (b) Each principal filament is capable of moving the ordinary filaments to which it is attached. This movement (flapping movement) is due to the movements of the interfilamentar junctions which alternatively move up and down at right angles to their length. This motion is independent of the branchial nerve and can be produced by direct stimulation of very tiny pieces of the individual filaments. 4. The significance of gill movements to feeding habits is discussed. The course of food particles depends on the nature of the stimuli affecting the gill. Histological. 5. The ctenidial axis and the principal filaments have a stratum of anastomosing nerve-cells which appear to form a true nerve-net comparable to that of the mantle. 6. The gill receives nerve-fibres from two sources, the brain and the visceral ganglion. The subsidiary branchial nerve is a structure hitherto unknown in the molluscan gill; so far its function is unknown. Each gill has four main longitudinal nerve-trunks. 7. The osphradium of the gill has a much more extensive distribution than has hitherto been supposed. 8. Two sets of muscles exist at the base of the gill-filaments, and these are responsible for movements of the lamellae. The muscle-fibres are non-striated. 9. The principal filaments are connected to the ordinary filaments by processes containing true muscle-cells, and by these cells movements of the filaments are effected.

Soft Palate Reflex: Technical Requirements and First Results

1992 ◽  
Vol 29 (4) ◽  
pp. 340-345 ◽  
Author(s):  
Godber S. Godbersen ◽  
Johannes Schneider-Littfeld ◽  
Jochen A. Werner ◽  
Sönke Wolters ◽  
Axel Pellner
Keyword(s):  
Soft Palate ◽  
Healthy Subjects ◽  
Processing System ◽  
Data Processing System ◽  
Response Latencies ◽  
Technical Requirements ◽  
First Results ◽  
The Individual ◽  
Electromyographic Signals ◽  
Stimulation Of

The present study describes technical prerequisites for soft palate reflex measurements and first results. Reflex measurements can be done using standard electromyographic methods. The data-processing system that records and processes the electromyographic signals was activated when the soft palate was stimulated by a newly developed device. The first results of objective soft palate reflex measurements in 15 healthy subjects show that the musculus levator veli palatini reacts to a mechanical stimulation of the soft palate with a contraction that can be measured electromyographicslly. The response latencies were constant in the individual subjects. In 12 subjects a minimum of 30 ms and a maximum of 61 ms was recorded. In one healthy subject, the reflex was activated only after 167 ms. No reflex could be evoked in two subjects. The stimulus was always supraliminal. Reaction time was longer following surface anesthesia of the oral mucosa.

scholarly journals Theatres of Closure: Process and Performance in Inhumation Burial Rites in Early Medieval Britain

2020 ◽  
Vol 30 (3) ◽  
pp. 389-412
Author(s):  
Sue Harrington ◽  
Stuart Brookes ◽  
Sarah Semple ◽  
Andrew Millard
Keyword(s):  
Material Culture ◽  
Body Position ◽  
The Body ◽  
Cultural Issues ◽  
Early Medieval ◽  
Group Perceptions ◽  
Burial Rites ◽  
Funerary Ritual ◽  
And Performance ◽  
The Individual

Inhumation burials are recorded in Britain and Europe during excavations in a standardized way, especially graves of early medieval date. Just a limited number of attributes are usually foregrounded and these mainly concern skeletal identification, the grave plan and, when a burial is furnished, a list of objects, particularly metalwork, as well as occasional reference to burial structures, if present. In this paper, we argue that concealed within these recorded details are attributes that often receive little attention, but which can provide evidence for community investment in the individual funerary rite. These include grave orientation, grave morphology, the body position and the empty spaces in the grave, as well as categories of material culture. We argue here that these factors enable us to define communal burial profiles and can facilitate the identification of group perceptions and actions in dealing with death. By capitalizing on these additional aspects of funerary ritual, archaeologists can move away from a general dependency on well-furnished burials as the main stepping-off point for discussion of social and cultural issues. This has particular relevance for regions where unfurnished burial rites are the norm and where furnished rites do not rely on a wealth of metalwork.

Nonlinear Tension Summation of Different Combinations of Motor Units in the Anesthetized Cat Peroneus Longus Muscle

1999 ◽  
Vol 81 (2) ◽  
pp. 771-780 ◽  
Author(s):  
D. Troiani ◽  
G. M. Filippi ◽  
F. Andreasi Bassi
Keyword(s):  
Stimulus Frequency ◽  
Correlation Coefficients ◽  
Motor Units ◽  
Linear Summation ◽  
Peroneus Longus ◽  
Longus Muscle ◽  
The Individual ◽  
And Shifts ◽  
Stimulation Of ◽  
Anesthetized Cat

Nonlinear tension summation of different combinations of motor units in the anesthetized cat peroneus longus muscle. The purpose of this study was to examine the linearity of summation of the forces produced by the stimulation of different combinations of type identified motor units (MUs) in the cat peroneus longus muscle (PL) under isometric conditions. The muscle was fixed at its twitch optimal length, and the tension produced by the single MU was recorded during 24- and 72-Hz stimulation. The summation analysis was first carried out for MUs belonging to the same functional group, and then different combinations of fast fatigable (FF) MUs were added to the nonfatigable slow (S) and fatigue resistant (FR) group. The tension resulting from the combined stimulation of increasing numbers of MUs (measured tension) was evaluated and compared with the linearly predicted value, calculated by adding algebraically the tension produced by the individual MUs assembled in the combination (calculated tension). Tension summation displayed deviations from linearity. S and FR MUs mainly showed marked more than linear summation; FF MUs yielded either more or less than linear summation; and, when the FF units were recruited after the S and FR MUs, less than linear summation always occurred. The magnitude of the nonlinear summation appeared stimulus frequency dependent for the fatigable FF and FI group. The relationship between measured tension and calculated tension for each MU combination was examined, and linear regression lines were fitted to each set of data. The high correlation coefficients and the different slope values for the different MU-type combinations suggested that the nonlinear summation was MU-type specific. The mechanisms of nonlinear summations are discussed by considering the consequences of internal shortening and thus the mechanical interactions among MUs and shifts in muscle fiber length to a more or less advantageous portion of single MU length-tension curves.

scholarly journals Self-Motion Signals in Vestibular Nuclei Neurons Projecting to the Thalamus in the Alert Squirrel Monkey

2009 ◽  
Vol 101 (4) ◽  
pp. 1730-1741 ◽  
Author(s):  
Vladimir Marlinski ◽  
Robert A. McCrea
Keyword(s):  
Electrical Stimulation ◽  
Vertical Axis ◽  
Vestibular Nuclei ◽  
Head Movements ◽  
Stimulus Velocity ◽  
The Earth ◽  
The Mean ◽  
Self Motion ◽  
Head Rotations ◽  
Stimulation Of

Sixty vestibular nuclei neurons antidromically activated by electrical stimulation of the ventroposterior thalamus were recorded in two alert squirrel monkeys. The majority of these neurons were monosynaptically activated by vestibular nerve electrical stimulation. Forty-seven neurons responded to animal rotations around the earth-vertical axis; 16 of them also responded to translations in the horizontal plane. The mean sensitivity to 0.5-Hz rotations of 80°/s velocity was 0.40 ± 0.31 spikes·s−1·deg−1·s−1. Rotational responses were in phase with stimulus velocity. Sensitivities to 0.5-Hz translations of 0.1 g acceleration varied from 92.2 to 359 spikes·s−1· g−1 and response phases varied from 10.1° lead to −98° lag. The firing behavior in 28 neurons was studied during rotation of the whole animal, of the trunk, and voluntary and involuntary rotations of the head. Two classes of vestibulothalamic neurons were distinguished. One class of neurons generated signals related to movement of the head that were similar either when the head and trunk move together or when the head moves on the stationary trunk. A fraction of these neurons fired during involuntary head movements only. A second class of neurons generated signals related to movement of the trunk. They responded when the trunk moved alone or simultaneously with the head, but did not respond to head rotations while the trunk was stationary.

scholarly journals Multisensory contribution in visuospatial orientation: an interaction between neck and trunk proprioception

2021 ◽  
Author(s):  
Jason McCarthy ◽  
Patricia Castro ◽  
Rachael Cottier ◽  
Joseph Buttell ◽  
Qadeer Arshad ◽  
...  
Keyword(s):  
Spatial Orientation ◽  
Visual Information ◽  
Visual Cues ◽  
Body Position ◽  
The Body ◽  
Visual Inputs ◽  
Visual Vertical ◽  
The Right ◽  
Trunk Position ◽  
The Brain

AbstractA coherent perception of spatial orientation is key in maintaining postural control. To achieve this the brain must access sensory inputs encoding both the body and the head position and integrate them with incoming visual information. Here we isolated the contribution of proprioception to verticality perception and further investigated whether changing the body position without moving the head can modulate visual dependence—the extent to which an individual relies on visual cues for spatial orientation. Spatial orientation was measured in ten healthy individuals [6 female; 25–47 years (SD 7.8 years)] using a virtual reality based subjective visual vertical (SVV) task. Individuals aligned an arrow to their perceived gravitational vertical, initially against a static black background (10 trials), and then in other conditions with clockwise and counterclockwise background rotations (each 10 trials). In all conditions, subjects were seated first in the upright position, then with trunk tilted 20° to the right, followed by 20° to the left while the head was always aligned vertically. The SVV error was modulated by the trunk position, and it was greater when the trunk was tilted to the left compared to right or upright trunk positions (p < 0.001). Likewise, background rotation had an effect on SVV errors as these were greater with counterclockwise visual rotation compared to static background and clockwise roll motion (p < 0.001). Our results show that the interaction between neck and trunk proprioception can modulate how visual inputs affect spatial orientation.

Total Body Nitrogen and Its Relation to Body Potassium and Fat-Free Mass in Healthy Subjects

1981 ◽  
Vol 61 (4) ◽  
pp. 457-462 ◽  
Author(s):  
L. Burkinshaw ◽  
D. B. Morgan ◽  
N. P. Silverton ◽  
R. D. Thomas
Keyword(s):  
Standard Deviation ◽  
Healthy Subjects ◽  
Skinfold Thickness ◽  
Mean Value ◽  
The Body ◽  
Fat Free Mass ◽  
Total Body Potassium ◽  
Individual Values ◽  
Total Body ◽  
The Individual

1. The amount of lean tissue in the body can be assessed by measuring total body nitrogen, total body potassium or fat-free mass. To compare these techniques we have measured total body nitrogen, total body potassium and fat-free mass in 91 healthy subjects (62 males, 29 females). 2. Total body nitrogen in the women and civilian men agreed closely with the few values reported previously and was closely related to total body potassium and fat-free mass. 3. The simplest estimate of total body nitrogen in a subject whose body content has not been measured is the mean value for healthy people of the same sex. The standard deviation of individual values about this mean is 253 g. The precision of the estimate can be improved considerably by predicting body nitrogen from fat-free mass (156 g) and somewhat more by predicting it from body potassium (115 g). The error of measuring total body nitrogen directly is approximately 76 g. 4. When an individual's total body potassium is measured in a search for potassium depletion, the observed value must be compared with the value expected if the subject were healthy. The standard deviation of the healthy values about the group means is 408 mmol. The precision of the estimate can be improved by predicting total body potassium from fat-free mass (sd 237 mmol), and rather more by predicting it from total body nitrogen (sd 186 mmol). If gross body composition is normal, measurement of total body nitrogen has little advantage over measurement of fat-free mass by the anthropometric technique. 5. These results suggest that the simpler measure of fat-free mass from body weight and skinfold thickness has a major role in the assessment of total body nitrogen, and thus lean body tissue, in the individual.

scholarly journals Introducing Biodynamic Craniosacral Therapy (BCST) into the Landscape of Jungian Thought

2017 ◽  
Vol 12 ◽  
pp. 45-55
Author(s):  
Jane E. Shaw
Keyword(s):  
Clinical Experience ◽  
Natural World ◽  
The Body ◽  
Human Organism ◽  
Light Touch ◽  
Jungian Theory ◽  
The Earth ◽  
Craniosacral Therapy ◽  
The Individual ◽  
Embodied Practice

Whereas research in the craniosacral field tends to focus on the benefits for the individual, in this paper I go a step further to argue that because of its psychoid nature, biodynamic craniosacral therapy (BCST) acts as an embodied practice to raise earth consciousness at both the collective and individual levels. The therapy is a light-touch practice grounded in empathetic presence in which practitioners work to attune the subtle rhythms of their own body, the client’s body, and the “body” of the environment and natural world in which they meet. Referencing my clinical experience, the essay proposes that craniosacral biodynamics, bringing consciousness to the human organism, may offer a felt experience of the interconnectedness of all being, even bringing to consciousness our relationship with the earth itself. This essay highlights where Jungian theory and BCST not only overlap but also where they might support each other to revision our relationship to the planet.

scholarly journals III. A further minute analysis by electric stimulation of the so-called motor region (facial area) of the cortex cerebri in the monkey ( Macacus sinicus )

1893 ◽  
Vol 53 (321-325) ◽  
pp. 463-463
Keyword(s):  
Electric Stimulation ◽  
The Body ◽  
Lower Lip ◽  
Bonnet Monkey ◽  
The Face ◽  
Cortex Cerebri ◽  
Facial Area ◽  
Motor Region ◽  
The Individual ◽  
Stimulation Of

In the paper of which this is an abstract the authors have completed the minute analysis of the movements elicited by excitation of the excitable (so-called motor) region of the cortex cerebri in the Bonnet Monkey ( Macacus sinicus ). The portions hitherto examined haying been those in which the movements of the limbs were represented, the facial area was chosen for the present research. After an historical introduction and a description of the anatomy of the region investigated, the method of notation and record of results is discussed. Considering that in this part of the cortex cerebri there is well-defined representation of movements of both sides of the body, the question of bilaterality of representation is raised, and attention directed to its importance. The analysis of the results obtained showed that there existed precise localisation for the movements of the individual portions of the face, even to that of half the lower lip.

Effects of Body Position on Judgment of the Postural Vertical

1965 ◽  
Vol 21 (3) ◽  
pp. 783-786 ◽  
Author(s):  
George A. Gescheider ◽  
John H. Wright
Keyword(s):  
Visual Cues ◽  
Body Position ◽  
The Body ◽  
Sitting Position ◽  
Experimental Conditions ◽  
Lateral Tilt ◽  
Left And Right

Each of 60 male Ss made 20 judgments of the postural vertical in the absence of visual cues. 10 Ss were randomly assigned to each of the 6 experimental conditions defined by left or right lateral tilt in a prone, supine, or sitting body position. In all conditions Ss consistently underestimated the postural vertical. Significantly larger errors were made by Ss tilted in the sitting position than by Ss tilted in the prone or supine positions. Performance in the prone and supine positions did not differ. No differences were obtained between tilting in the left and right quadrants for any of the body positions. Practice led to a significant decrease in error under all conditions.

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