scholarly journals Effect of vision loss on plasticity of the head and neck proprioception

2021 ◽  
Vol 14 (7) ◽  
pp. 1059-1065
Author(s):  
Tian-Yu Jiang ◽  
◽  
Dong-Mei Wu ◽  
Lin Zhang ◽  
Chang-Shui Weng ◽  
...  
Keyword(s):  
Head And Neck ◽  
Vision Loss ◽  
Low Vision ◽  
Head Rotation ◽  
Hand Dominance ◽  
Right Hand ◽  
Neck Proprioception ◽  
Left And Right ◽  
The Right

AIM: To investigate whether head and neck proprioception and motor control could be compensatory enhanced by long-term vision loss or impairment. METHODS: Individuals who were blind, low vision or sighted were included in the study, which would undergo the head repositioning test (HRT). The constant error (CE), absolute error (AE), variable error (VE) and root mean square error (RMSE) of each subject were statistically analyzed. Data were analyzed using the SAS 9.4. Tukey-Kramer for one-way ANOVA was used for comparison of blind, low vision, and sighted subjects, as well as to compare subjects with balanced vision, strong vision in the left eye and strong vision in the right eye. Independent sample t-test was used to compare subjects with congenital blindness and acquired blindness, as well as left and right hand dominance subjects. RESULTS: A total of 90 individuals (25 blind subjects, 31 low vision subjects, and 34 sighted subjects) were included in the study. Among the blind subjects, 14 cases had congenital blindness and 11 cases had acquired blindness. Among the blind and low vision subjects, 21 cases had balanced binocular vision, 17 cases had strong vision in the left eye and 18 cases had strong vision in the right eye. Among all subjects, 11 cases were left hand dominance, and 79 cases were right hand dominance. There were significant differences in AE, VE, and RMSE in head rotation between blind, low vision, and sighted subjects (P<0.01), in AE, VE, and RMSE between blind and sighted (P<0.01), and in VE and RMSE between low vision and sighted (P<0.05). No significant difference between blind and low vision (P>0.05). Significant differences in CE and AE of head right rotation and CE of general head rotation between congenital and acquired (P<0.05). No significant differences between left and right hand dominance and in balance or not of binocular vision (P>0.05). CONCLUSION: Long-term vision loss or impairment does not lead to compensatory enhancement of head and neck proprioception and motor control. Acquired experience contributes to HRT performance in the blind and has long-lasting effects on plasticity in the development of proprioception and sensorimotor control.

Activator calcium and myocardial contractility in fetal sheep exposed to long-term high-altitude hypoxia

1997 ◽  
Vol 272 (3) ◽  
pp. H1196-H1204 ◽  
Author(s):  
V. A. Browne ◽  
V. M. Stiffel ◽  
W. J. Pearce ◽  
L. D. Longo ◽  
R. D. Gilbert
Keyword(s):  
High Altitude ◽  
Myocardial Contractility ◽  
Active Tension ◽  
Fetal Sheep ◽  
Lower Maximum ◽  
Left And Right ◽  
Baseline Values ◽  
The Right ◽  
Maximum Rate Of Rise

We studied myocardial contractility in fetal sheep from ewes exposed to approximately 112 days of hypoxia at high altitude (3,820 m). We measured the inotropic response to extracellular Ca2+ concentration ([Ca2+]o, 0.2-10 mM) and ryanodine (10(-10) to 10(-4) M) in isometrically contracting papillary muscles and quantified dihydropyridine (DHPR) and ryanodine (RyR) receptors. In hypoxic fetuses, curves describing the force-[Ca2+]o relationship were shifted left, and the top plateaus were decreased by approximately 35% in both left and right ventricles. In normoxic and hypoxic fetuses, ryanodine (10(-4) M) reduced maximum active tension (Tmax) to approximately 25-40% of baseline values, indicating that the sarcoplasmic reticulum was the chief source of activator Ca2+ and that Ca2+ influx alone was not sufficient to activate a contraction of normal amplitude. Hypoxia resulted in a lower Tmax in the right ventricle and a lower maximum rate of rise in the left ventricle after treatment with ryanodine. DHPR number did not change, but RyR number and the RyR/DHPR in both ventricles were higher in hypoxic fetuses. We conclude that hypoxia decreases contractility, possibly by reducing the availability of activator Ca2+. Further studies are needed to directly measure the Ca2+ current and intracellular Ca2+ transient and to examine myofilament protein and adenosinetriphosphatase activity.

Head Rotation Influences the Geometric Features of the Stenotic Carotid Bifurcation

2012 ◽  
Author(s):  
Nicolas Aristokleous ◽  
Ioannis Seimenis ◽  
Yannis Papaharilaou ◽  
Eleni Eracleous ◽  
Georgios C. Georgiou ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Carotid Arteries ◽  
Head Rotation ◽  
Carotid Bifurcation ◽  
Geometric Features ◽  
Hemodynamic Variables ◽  
Prone Sleeping ◽  
Left And Right ◽  
The Right ◽  
Geometric Changes

Previous investigators have reported that posture changes may influence the geometry and hemodynamics of the carotid bifurcation [1,2]. As a result, head rotation may cause geometric changes that alter the hemodynamic variables previously cited to correlate with the development of atherosclerosis. Glor et al. [1] had reported changes in the right carotid bifurcation geometry with leftward rotation of the head. Aristokleous et al. [2] have reported that geometric differences in the right and left carotid bifurcation occur with a rightward rotation of the head in 10 healthy volunteers [2]. Also, a similar study on bilateral head rotation on the left and right carotid bifurcation of two volunteers has shown similar results [3]. In this study a group of four patients with atherosclerotic disease in the carotid arteries was investigated at two head postures, a) the supine neutral and b) the prone sleeping with head rotation leftwards up to 80° to investigate the level of stenosis and the changes in geometric parameters with head rotation.

Hemispheric Differences in the Relationship Between Corticomotor Excitability Changes Following a Fine-Motor Task and Motor Learning

2004 ◽  
Vol 91 (4) ◽  
pp. 1570-1578 ◽  
Author(s):  
Michael I. Garry ◽  
Gary Kamen ◽  
Michael A. Nordstrom
Keyword(s):  
Motor Learning ◽  
Motor Performance ◽  
Fine Motor ◽  
Hemispheric Differences ◽  
Corticomotor Excitability ◽  
Hand Muscles ◽  
Right Hand ◽  
Left And Right ◽  
The Right ◽  
Intrinsic Hand Muscles

Motor performance induces a postexercise increase in corticomotor excitability that may be associated with motor learning. We investigated whether there are hemispheric differences in the extent and/or time course of changes in corticomotor excitability following a manipulation task (Purdue pegboard) and their relationship with motor performance. Single- and paired-pulse (3 ms) transcranial magnetic stimulation (TMS) was used to assess task-induced facilitation of the muscle evoked potential (MEP) and intracortical inhibition (ICI) for three intrinsic hand muscles acting on digits 1, 2, and 5. Fifteen right-handed subjects performed three 30-s pegboard trials with left or right hand in separate sessions. TMS was applied to contralateral motor cortex before and after performance. Number of pegs placed was higher with the right hand, and performance improved (motor learning) with both hands over the three trials. MEP facilitation following performance was short-lasting (<15 min), selective for muscles engaged in gripping the pegs, and of similar magnitude in left and right hands. ICI was reduced immediately following performance with the right hand, but not the left. The extent of MEP facilitation was positively correlated with motor learning for the right hand only. We conclude that the pegboard task induces a selective, short-lasting change in excitability of corticospinal neurons controlling intrinsic hand muscles engaged in the task. Only left hemisphere changes were related to motor learning. This asymmetry may reflect different behavioral strategies for performance improvement with left and right upper limb in this task or hemispheric differences in the control of skilled hand movements.

scholarly journals Lateral comparisons using Fishman's skeletal maturation assessment

2014 ◽  
Vol 85 (3) ◽  
pp. 408-412 ◽  
Author(s):  
Abraham N. Safer ◽  
Peter Homel ◽  
David D. Chung
Keyword(s):  
Bone Development ◽  
Surgical Patients ◽  
Skeletal Maturation ◽  
Age And Gender ◽  
Left Hand ◽  
Right Hand ◽  
Significant Difference ◽  
Left And Right ◽  
And Gender ◽  
The Right

ABSTRACT Objective:  To assess lateral differences between ossification events and stages of bone development in the hands and wrists utilizing Fishman's skeletal maturation indicators (SMIs). Materials and Methods:  The skeletal ages of 125 subjects, aged 8 to 20 years, were determined with left and right hand-wrist radiographs using Fishman's SMI assessment. Each subject was also given the Edinburgh Handedness Questionnaire to assess handedness. The skeletal ages of both hand-wrist radiographs were analyzed against each other, handedness, chronologic age, and gender. Results:  There were no significant differences overall in right and left SMI scores (P  =  .70); 79% of all patients showed no difference in right and left SMI scores, regardless of handedness, gender, or age. However, when patients were categorized based on clinical levels of SMI score for the right hand-wrist, there was a significant difference (P  =  .01) between the SMI 1-3 group and the SMI 11 group. Subjects in the SMI 1-3 group were more likely to show a left &gt; right SMI score, while subjects in the SMI 11 group were likely to show a right &gt; left SMI score. Conclusion:  Although no significant overall lateral differences in SMI scores were noted, it may be advisable to obtain a left hand-wrist radiograph and/or additional diagnostic information to estimate completion of growth in young surgical patients.

Evaluation of Hand-Dominance on Manual Control of Aircraft

1996 ◽  
Vol 40 (2) ◽  
pp. 72-76 ◽  
Author(s):  
Valerie J. Gawron ◽  
James E. Priest
Keyword(s):  
Manual Control ◽  
Dominant Hand ◽  
Hand Dominance ◽  
Transport Aircraft ◽  
Left Hand ◽  
Tracking Tasks ◽  
Right Hand ◽  
Hand Control ◽  
Left And Right ◽  
Task Simulation

In the transport aircraft community the non-dominant hand control of aircraft is the norm. This historical precedence may be biasing the cockpit designs of the newer fly-by-wire aircraft which utilize a small sidestick controller rather than a wheel-column. Very little data are available to determine what effect non-dominant hand control using small throw controllers has on the pilot operator. To provide such data, a part-task simulation study was undertaken. Three different compensatory tracking tasks were performed with both left and right hand-controllers. Six right-hand dominant and three left-hand dominant subjects performed all three tasks, with both controllers. The results indicate that performance degraded and workload increased when the pilots were forced to use their non-dominant hand.

scholarly journals Drawing with the Non-dominant Hand: Implications for the Study of Construction

1998 ◽  
Vol 25 (4) ◽  
pp. 306-309 ◽  
Author(s):  
Sherma Zacharias ◽  
Andrew Kirk
Keyword(s):  
Neurological Disease ◽  
Right Hemisphere ◽  
Normal Subjects ◽  
Elderly Subjects ◽  
Dominant Hand ◽  
Left Hand ◽  
Right Hand ◽  
Left And Right ◽  
The Right ◽  
Right And Left Hand

ABSTRACT:Background:Constructional impairment following left vs. right hemisphere damage has been extensively studied using drawing tasks. A confounding factor in these studies is that right-handed patients with left hemisphere damage (LHD) are often forced by weakness to use their non-dominant (left) hand or hemiparetic dominant hand. Qualitative differences in the drawing characteristics of left and right hand drawings by normal subjects have not previously been characterized. The present study was undertaken to determine the qualitative differences between left and right hand drawings of normal subjects.Methods:Thirty right-handed, elderly subjects without a history of neurological disease were asked to draw, from memory, seven objects using the right and left hand. Half of the subjects were randomly assigned to draw with the left hand first, and half the right hand first. Right and left hand drawings were compared using a standardized scoring system utilized in several previous studies of drawing in focal and diffuse neurological disease. Each drawing was scored on eighteen criteria. Right and left hand drawing scores were then compared using the t-test for paired samples or the Wilcoxon matched-pairs testResults:Drawings made using the left hand were found to be significantly simpler, more tremulous and of poorer overall quality than drawings made by the same subjects using the right hand.Conclusions:The deficits found in left versus right hand drawings of normals are similar to those found in patients with LHD, suggesting that much of the drawing impairment seen following LHD is due to an elementary motor disturbance related to use of the non-dominant hand.

scholarly journals Are left- and right-eye pupil sizes always equal?

2019 ◽  
Vol 12 (2) ◽  
Author(s):  
Gonca Gokce Menekse Dalveren ◽  
Nergiz Ercil Cagiltay
Keyword(s):  
Cognitive Load ◽  
Movement Analysis ◽  
Difficulty Level ◽  
Human Beings ◽  
Left Hand ◽  
Surgical Residents ◽  
Right Hand ◽  
Significant Difference ◽  
Left And Right ◽  
The Right

Eye movements provide very critical information about the cognitive load and behaviors of human beings. Earlier studies report that under normal conditions, the left- and right-eye pupil sizes are equal. For this reason, most studies undertaking eye-movement analysis are conducted by only considering the pupil size of a single eye or taking the average size of both eye pupils. This study attempts to offer a better understanding concerning whether there are any differences between the left- and right-eye pupil sizes of the right-handed surgical residents while performing surgical tasks in a computer-based simulation environment under different conditions (left hand, right hand and both hands). According to the results, in many cases, the right-eye pupil sizes of the participants were larger than their left-eye pupil sizes while performing the tasks under right-hand and both-hands conditions. However, no significant difference was found in relation to the tasks performed under left-hand condition in all scenarios. These results are very critical to shed further light on the cognitive load of the surgical residents by analyzing their left-eye and right-eye pupil sizes. Further research is required to investigate the effect of the difficulty level of each scenario, its appropriateness with the skill level of the participants, and handedness on the differences between the left- and right-eye pupil sizes.

scholarly journals Political Left and Right: Our Hands-On Logic

2014 ◽  
Vol 2 (1) ◽  
pp. 335-346
Author(s):  
Frits Bienfait ◽  
Walter E. A. van Beek
Keyword(s):  
Social Order ◽  
Essential Feature ◽  
Social Contexts ◽  
Right Hand ◽  
Hands On ◽  
The World ◽  
Political Left ◽  
Left And Right ◽  
Definition Of ◽  
The Right

The origins and immediate vitality of the left/right divide which emerged in French revolutionary politics from 1789 can only be understood against the background of a much older classification dynamic based on the primacy of the right hand, first described by Robert Hertz in 1909. This dynamic infused political thinking first in Versailles and since 1815 in democracies throughout the world. In the process, the classical left/right polarity acquired a new dimension: the complementary notions of ‘accepting’ and ‘questioning’ the existing social order. An essential feature of both the age-old classical polarity and the ensuing political polarity is that they are intimately bound up with local and evolving social contexts: there is no single content-based definition of left and right. As long as the majority of us are predisposed to use our right hand when acting in the world, ‘left versus right’ will remain the most important political antithesis in western-type democracies.

scholarly journals Transection of the ventral hippocampal commissure impairs spatial reference but not contextual or spatial working memory

2021 ◽  
Vol 29 (1) ◽  
pp. 29-37
Author(s):  
Jake T. Jordan ◽  
Yi Tong ◽  
Carolyn L. Pytte
Keyword(s):  
Working Memory ◽  
Learning And Memory ◽  
Spatial Working Memory ◽  
Hemispheric Lateralization ◽  
Long Term Memory ◽  
Substrate Stability ◽  
Short And Long Term ◽  
Left And Right ◽  
The Right

Plasticity is a neural phenomenon in which experience induces long-lasting changes to neuronal circuits and is at the center of most neurobiological theories of learning and memory. However, too much plasticity is maladaptive and must be balanced with substrate stability. Area CA3 of the hippocampus provides such a balance via hemispheric lateralization, with the left hemisphere dominant in providing plasticity and the right specialized for stability. Left and right CA3 project bilaterally to CA1; however, it is not known whether this downstream merging of lateralized plasticity and stability is functional. We hypothesized that interhemispheric convergence of input from these pathways is essential for integrating spatial memory stored in the left CA3 with navigational working memory facilitated by the right CA3. To test this, we severed interhemispheric connections between the left and right hippocampi in mice and assessed learning and memory. Despite damage to this major hippocampal fiber tract, hippocampus-dependent navigational working memory and short- and long-term memory were both spared. However, tasks that required the integration of information retrieved from memory with ongoing navigational working memory and navigation were impaired. We propose that one function of interhemispheric communication in the mouse hippocampus is to integrate lateralized processing of plastic and stable circuits to facilitate memory-guided spatial navigation.

Comparative Analysis of Proprioception in Left and Right Arms

1965 ◽  
Vol 17 (2) ◽  
pp. 149-157 ◽  
Author(s):  
Maria Wyke
Keyword(s):  
Comparative Analysis ◽  
Head And Neck ◽  
Sensory Input ◽  
The Body ◽  
Limb Movements ◽  
Pointing Error ◽  
Left And Right ◽  
The Right ◽  
Genetically Determined ◽  
Better Than

Using the “kinaesthetic memory for the target” technique, differences in the accuracy of pointing to a target with the right and left arms are analysed. The effect of rotation of the head to left and right upon this process is also studied. With the head normally orientated, it was found that pointing with the right arm is significantly better than with the left. Accuracy of pointing is greater with the target directly in front of the body than when it lies to either left or right side. When the head is rotated, the direction of the pointing error is inversely related to the direction of rotation. The study suggests that the precision of control over arm (in the absence of vision) is related to the varying ability of individual subjects to correlate limb movements with the prevailing orientation of the body, especially of the head and neck. This is additional to the influences of genetically-determined handedness and of the sensory input from the moving limb.

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