scholarly journals Neck muscle spindle noise biases reaches in a multisensory integration task

2018 ◽  
Vol 120 (3) ◽  
pp. 893-909 ◽  
Author(s):  
Parisa Abedi Khoozani ◽  
Gunnar Blohm
Keyword(s):  
Multisensory Integration ◽  
Reference Frames ◽  
Muscle Tone ◽  
Three Dimensional ◽  
The Body ◽  
Parameter Estimates ◽  
Neck Muscle ◽  
Head Roll ◽  
Reach Movements ◽  
The Brain

Reference frame transformations (RFTs) are crucial components of sensorimotor transformations in the brain. Stochasticity in RFTs has been suggested to add noise to the transformed signal due to variability in transformation parameter estimates (e.g., angle) as well as the stochastic nature of computations in spiking networks of neurons. Here, we varied the RFT angle together with the associated variability and evaluated the behavioral impact in a reaching task that required variability-dependent visual-proprioceptive multisensory integration. Crucially, reaches were performed with the head either straight or rolled 30° to either shoulder, and we also applied neck loads of 0 or 1.8 kg (left or right) in a 3 × 3 design, resulting in different combinations of estimated head roll angle magnitude and variance required in RFTs. A novel three-dimensional stochastic model of multisensory integration across reference frames was fitted to the data and captured our main behavioral findings: 1) neck load biased head angle estimation across all head roll orientations, resulting in systematic shifts in reach errors; 2) increased neck muscle tone led to increased reach variability due to signal-dependent noise; and 3) both head roll and neck load created larger angular errors in reaches to visual targets away from the body compared with reaches toward the body. These results show that noise in muscle spindles and stochasticity in general have a tangible effect on RFTs underlying reach planning. Since RFTs are omnipresent in the brain, our results could have implications for processes as diverse as motor control, decision making, posture/balance control, and perception. NEW & NOTEWORTHY We show that increasing neck muscle tone systematically biases reach movements. A novel three-dimensional multisensory integration across reference frames model captures the data well and provides evidence that the brain must have online knowledge of full-body geometry together with the associated variability to plan reach movements accurately.

scholarly journals Neck muscle spindle noise biases reaches in a multi-sensory integration task

2017 ◽  
Author(s):  
Parisa Abedi Khoozani ◽  
Gunnar Blohm
Keyword(s):  
Sensory Integration ◽  
Reference Frames ◽  
Balance Control ◽  
Muscle Tone ◽  
The Body ◽  
Parameter Estimates ◽  
Neck Muscle ◽  
Head Roll ◽  
Reach Movements ◽  
The Brain

AbstractReference frame Transformations (RFTs) are crucial components of sensorimotor transformations in the brain. Stochasticity in RFTs has been suggested to add noise to the transformed signal due to variability in transformation parameter estimates (e.g. angle) as well as the stochastic nature of computations in spiking networks of neurons. Here, we varied the RFT angle together with the associated variability and evaluated the behavioral impact in a reaching task that required variability-dependent visual-proprioceptive multi-sensory integration. Crucially, reaches were performed with the head either straight or rolled 30deg to either shoulder and we also applied neck loads of 0 or 1.8kg (left or right) in a 3×3 design, resulting in different combinations of estimated head roll angle magnitude and variance required in RFTs. A novel 3D stochastic model of multi-sensory integration across reference frames was fitted to the data and captured our main behavioral findings: (1) neck load biased head angle estimation across all head roll orientations resulting in systematic shifts in reach errors; (2) Increased neck muscle tone led to increased reach variability, due to signal-dependent noise; (3) both head roll and neck load created larger angular errors in reaches to visual targets away from the body compared to reaches toward the body. These results show that noise in muscle spindles and stochasticity in general have a tangible effect on RFTs underlying reach planning. Since RFTs are omnipresent in the brain, our results could have implication for processes as diverse as motor control, decision making, posture / balance control, and perception.New & NoteworthyWe show that increasing neck muscle tone systematically biases reach movements. A novel 3D multisensory integration across reference frames model captures the data well and provides evidence that the brain must have online knowledge of full body geometry together with the associated variability to accurately plan reach movements.

Nondestructive imaging of the internal microstructure of vessels and nerve fibers in rat spinal cord using phase-contrast synchrotron radiation microtomography

2017 ◽  
Vol 24 (2) ◽  
pp. 482-489 ◽  
Author(s):  
Jianzhong Hu ◽  
Ping Li ◽  
Xianzhen Yin ◽  
Tianding Wu ◽  
Yong Cao ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Synchrotron Radiation ◽  
Phase Contrast ◽  
Three Dimensional ◽  
Nerve Fibers ◽  
The Body ◽  
Rat Spinal Cord ◽  
Nondestructive Imaging ◽  
Synchrotron Radiation Microtomography ◽  
The Brain

The spinal cord is the primary neurological link between the brain and other parts of the body, but unlike those of the brain, advances in spinal cord imaging have been challenged by the more complicated and inhomogeneous anatomy of the spine. Fortunately with the advancement of high technology, phase-contrast synchrotron radiation microtomography has become widespread in scientific research because of its ability to generate high-quality and high-resolution images. In this study, this method has been employed for nondestructive imaging of the internal microstructure of rat spinal cord. Furthermore, digital virtual slices based on phase-contrast synchrotron radiation were compared with conventional histological sections. The three-dimensional internal microstructure of the intramedullary arteries and nerve fibers was vividly detected within the same spinal cord specimen without the application of a stain or contrast agent or sectioning. With the aid of image post-processing, an optimization of vessel and nerve fiber images was obtained. The findings indicated that phase-contrast synchrotron radiation microtomography is unique in the field of three-dimensional imaging and sets novel standards for pathophysiological investigations in various neurovascular diseases.

scholarly journals The impact of pelvic lateral rotation on hindlimb kinematics and stride length in the red-legged running frog, Kassina maculata

2019 ◽  
Vol 6 (5) ◽  
pp. 190060 ◽  
Author(s):  
Amber J. Collings ◽  
Laura B. Porro ◽  
Cameron Hill ◽  
Christopher T. Richards
Keyword(s):  
High Speed ◽  
Stride Length ◽  
Reference Frames ◽  
Comparative Anatomy ◽  
Three Dimensional ◽  
Video Data ◽  
The Body ◽  
Kinematic Models ◽  
Lateral Rotation ◽  
The Impact

Some frog species, such as Kassina maculata (red-legged running frog), use an asynchronous walking/running gait as their primary locomotor mode. Prior comparative anatomy work has suggested that lateral rotation of the pelvis improves walking performance by increasing hindlimb stride length; however, this hypothesis has never been tested. Using non-invasive methods, experimental high-speed video data collected from eight animals were used to create two three-dimensional kinematic models. These models, each fixed to alternative local anatomical reference frames, were used to investigate the hypothesis that lateral rotation of the mobile ilio-sacral joint in the anuran pelvis plays a propulsive role in walking locomotion by increasing hindlimb stride length. All frogs used a walking gait (duty factor greater than 0.5) despite travelling over a range of speeds (0.04–0.23 m s −1 ). The hindlimb joint motions throughout a single stride were temporally synchronized with lateral rotation of the pelvis. The pelvis itself, on average, underwent an angular excursion of 12.71° (±4.39°) with respect to the body midline during lateral rotation. However, comparison between our two kinematic models demonstrated that lateral rotation of the pelvis only increases the cranio-caudal excursion of the hindlimb modestly. Thus, we propose that pelvic lateral rotation is not a stride length augmenting mechanism in K. maculata .

scholarly journals Computations underlying the visuomotor transformation for smooth pursuit eye movements

2015 ◽  
Vol 113 (5) ◽  
pp. 1377-1399 ◽  
Author(s):  
T. Scott Murdison ◽  
Guillaume Leclercq ◽  
Philippe Lefèvre ◽  
Gunnar Blohm
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Reference Frames ◽  
Three Dimensional ◽  
Head Orientation ◽  
Smooth Pursuit Eye Movements ◽  
Visuomotor Transformation ◽  
Pursuit Eye Movements ◽  
Retinal Motion ◽  
The Brain

Smooth pursuit eye movements are driven by retinal motion and enable us to view moving targets with high acuity. Complicating the generation of these movements is the fact that different eye and head rotations can produce different retinal stimuli but giving rise to identical smooth pursuit trajectories. However, because our eyes accurately pursue targets regardless of eye and head orientation (Blohm G, Lefèvre P. J Neurophysiol 104: 2103–2115, 2010), the brain must somehow take these signals into account. To learn about the neural mechanisms potentially underlying this visual-to-motor transformation, we trained a physiologically inspired neural network model to combine two-dimensional (2D) retinal motion signals with three-dimensional (3D) eye and head orientation and velocity signals to generate a spatially correct 3D pursuit command. We then simulated conditions of 1) head roll-induced ocular counterroll, 2) oblique gaze-induced retinal rotations, 3) eccentric gazes (invoking the half-angle rule), and 4) optokinetic nystagmus to investigate how units in the intermediate layers of the network accounted for different 3D constraints. Simultaneously, we simulated electrophysiological recordings (visual and motor tunings) and microstimulation experiments to quantify the reference frames of signals at each processing stage. We found a gradual retinal-to-intermediate-to-spatial feedforward transformation through the hidden layers. Our model is the first to describe the general 3D transformation for smooth pursuit mediated by eye- and head-dependent gain modulation. Based on several testable experimental predictions, our model provides a mechanism by which the brain could perform the 3D visuomotor transformation for smooth pursuit.

The Excellence Grid – a tool to identify attributes that drive service excellence

2017 ◽  
Vol 34 (8) ◽  
pp. 1209-1228 ◽  
Author(s):  
Sheila Roy ◽  
Indrajit Mukherjee
Keyword(s):  
Three Dimensional ◽  
Performance Model ◽  
The Body ◽  
Parameter Estimates ◽  
Good Service ◽  
Kano Model ◽  
Content Type ◽  
Service Excellence ◽  
Body Of Knowledge ◽  
Asymmetric Impact

Purpose The purpose of this paper is to develop a tool, “The Excellence Grid,” to categorize attributes on the basis of their ability to impact customer perception of “excellence” in service compared to perception of “good” service. In addition, provide a three dimensional (3D) model for excellence-performance analysis, which can aid managers in formalizing the strategies for building perceptions of excellence about the service. Design/methodology/approach The positive zone of performance is analyzed through a two-function modeling technique of ordinal logistic regression (OLR) with the non-proportional odds to categorize attributes on grid. Tool is applied to two case studies to validate and establish the asymmetric impact of attributes on perceptions of “good service” and “excellent service.” Findings Similar to the Kano model for impact of attributes on positive and negative performances, findings from cases confirm the asymmetric impact of attributes on the positive zone of performance and establish “Excellence Grid” as a means to categorize attributes as drivers of excellence. Practical implications The “Excellence Grid” tool is expected to empower managers to focus on strategies directed toward the goal of “service excellence” and recommends that managers should not only strive for process improvement, but also sharpen the external communication of service excellence. Originality/value The “Excellence Grid” and the “3D Excellence-Performance model,” proposed in this research, are expected to enrich the body of knowledge on operational tools to achieve service excellence. Using parameter estimates of the two-function model of OLR for service quality has not yet been reported in open literature.

scholarly journals Reaching around obstacles accounts for uncertainty in coordinate transformations

2020 ◽  
Vol 123 (5) ◽  
pp. 1920-1932 ◽  
Author(s):  
Parisa Abedi Khoozani ◽  
Dimitris Voudouris ◽  
Gunnar Blohm ◽  
Katja Fiehler
Keyword(s):  
Movement Direction ◽  
Coordinate Transformations ◽  
Movement Variability ◽  
Head Roll ◽  
Reach Movements ◽  
The Brain

We show that changing body geometry such as head roll results in compensatory reaching behaviors around obstacles. Specifically, we observed head roll causes changed preferred movement direction and increased trajectory curvature. As has been shown before, head roll increases movement variability due to stochastic coordinate transformations. Thus these results provide evidence that the brain must consider the added movement variability caused by coordinate transformations for accurate reach movements.

scholarly journals Penyembuhan Baby Blues Syndrome dan Post-Partum Depression Melalui Chandra Namaskara dan Brahmari Pranayama

2020 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Ni Wayan Sri Prabawati Kusuma Dewi
Keyword(s):  
Adrenal Cortex ◽  
Muscle Tone ◽  
Post Partum ◽  
Premenstrual Dysphoric Disorder ◽  
Lateral Wall ◽  
The Body ◽  
Birth Canal ◽  
Post Partum Depression ◽  
Baby Blues ◽  
The Brain

<p>Babies born through both normal and caesarean (sc) procedures, 50-80% make the mother face the risk of baby blues syndrome and post-partum depression. Baby blues syndrome, occurs in the first 2 weeks after giving birth, triggered by physical changes such as  swelling of the breast, pain in the area around the birth canal and uterus, changes in muscle tone, physical and mental fatigue that the mother feels. While post-partum depression lasts several months to many years later, this syndrome begins with a psychiatric disorder suffered by the mother before pregnancy, psychosocial stress, inadequate social support, and premenstrual dysphoric disorder. For that, this condition needs to be addressed immediately, through the healing techniques of Chandra namaskara and Brahmari Pranayama. Chandra namaskara arouses the feminine energy, the lunar energy in the mother’s body, keeping the cerebral circulation fresh so that the sympathetic nerve activity diminishes. The effect of massage on the organs in the abdomen, increase peristaltic activity in the intestine, the lateral wall of the heart stretched perfectly so that no ischaemia occurs. Alteration of arthritis of the spinal joint can be removed by stretching the spinal muscles and ligaments between the vertebral bones through this series of asanas. While brahmari pranayama stimulates the brain part of the hypothalamus to activate the adrenal cortex system by sending signals to the pituitary gland so as not to secrete adrenocorticotropin (ACTH), so that ACTH, which had previously stimulated the outer layer of the adrenal glands (the adrenal cortex) to release a group of hormones (cortisol) did not secrete cortisol, but instead produced by the brain is actually the endhorpine that works for the body’s immune, regulate emotions, relax of the body and be able to eliminate depression.</p><p><br /><br /></p>

scholarly journals A low-cost three-dimensional laser surface scanning approach for defining body segment parameters

2017 ◽  
Vol 231 (11) ◽  
pp. 1064-1068 ◽  
Author(s):  
Petros Pandis ◽  
Anthony MJ Bull
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Dynamic Modelling ◽  
The Body ◽  
Parameter Estimates ◽  
Body Segment ◽  
Subject Specific ◽  
Actual Volume ◽  
System Body ◽  
Body Segment Parameters

Body segment parameters are used in many different applications in ergonomics as well as in dynamic modelling of the musculoskeletal system. Body segment parameters can be defined using different methods, including techniques that involve time-consuming manual measurements of the human body, used in conjunction with models or equations. In this study, a scanning technique for measuring subject-specific body segment parameters in an easy, fast, accurate and low-cost way was developed and validated. The scanner can obtain the body segment parameters in a single scanning operation, which takes between 8 and 10 s. The results obtained with the system show a standard deviation of 2.5% in volumetric measurements of the upper limb of a mannequin and 3.1% difference between scanning volume and actual volume. Finally, the maximum mean error for the moment of inertia by scanning a standard-sized homogeneous object was 2.2%. This study shows that a low-cost system can provide quick and accurate subject-specific body segment parameter estimates.

scholarly journals Digital Unwrapping of the Mummy of King Amenhotep I (1525–1504 BC) Using CT

2021 ◽  
Vol 8 ◽  
Author(s):  
Sahar N. Saleem ◽  
Zahi Hawass
Keyword(s):  
Cause Of Death ◽  
Anterior Abdominal Wall ◽  
Three Dimensional ◽  
The Body ◽  
Left Hemithorax ◽  
Modern Times ◽  
Non Invasive ◽  
The Face ◽  
Physical Features ◽  
The Brain

The mummy of King Amenhotep I (18th Dynasty c.1525–1504 BC) was reburied by the 21st Dynasty priests at Deir el-Bahari Royal Cache. In 1881 the mummy was found fully wrapped and was one of few royal mummies that have not been unwrapped in modern times. We hypothesized that non-invasive digital unwrapping using CT would provide insights on the physical appearance, health, cause of death, and mummification style of the mummy of King Amenhotep I. We examined the mummy with CT and generated two- and three-dimensional images for the head mask, bandages, and the virtually unwrapped mummy. CT enabled the visualization of the face of Amenhotep I who died around the age of 35 years. The teeth had minimal attrition. There was no CT evidence of pathological changes or cause of death. The body has been eviscerated via a vertical left flank incision. The heart is seen in the left hemithorax with an overlying amulet. The brain has not been removed. The mummy has 30 amulets/jewelry pieces including a beaded metallic (likely gold) girdle. The mummy suffered from multiple postmortem injuries likely inflicted by tomb robbers that have been likely treated by 21st Dynasty embalmers. These included fixing the detached head and neck to the body with a resin-treated linen band; covering a defect in the anterior abdominal wall with a band and placing two amulets beneath; placement of the detached left upper limb beside the body and wrapping it to the body. The transversely oriented right forearm is individually wrapped, likely representing the original 18th Dynasty mummification and considered the first known New Kingdom mummy with crossed arms at the chest. The head mask is made of cartonnage and has inlaid stone eyes. The digital unwrapping of the mummy of Amenhotep I using CT sets a unique opportunity to reveal the physical features of the King non-invasively, understand the mummification style early in the 18th Dynasty, and the reburial intervention style by 21st Dynasty embalmers. This study may make us gain confidence in the goodwill of the reburial project of the Royal mummies by the 21st dynasty priests.

Relationships between neck muscle electromyography and three-dimensional head kinematics during centrally induced torsional head perturbations

2012 ◽  
Vol 108 (11) ◽  
pp. 2867-2883 ◽  
Author(s):  
Farshad Farshadmanesh ◽  
Patrick Byrne ◽  
Hongying Wang ◽  
Brian D. Corneil ◽  
J. Douglas Crawford
Keyword(s):  
Three Dimensional ◽  
Head Rotation ◽  
Neck Muscle ◽  
Three Dimensional Model ◽  
Interstitial Nucleus Of Cajal ◽  
Head Kinematics ◽  
Torsional Coupling ◽  
Fixation Task ◽  
The Relationship ◽  
The Brain

The relationship between neck muscle electromyography (EMG) and torsional head rotation (about the nasooccipital axis) is difficult to assess during normal gaze behaviors with the head upright. Here, we induced acute head tilts similar to cervical dystonia (torticollis) in two monkeys by electrically stimulating 20 interstitial nucleus of Cajal (INC) sites or inactivating 19 INC sites by injection of muscimol. Animals engaged in a simple gaze fixation task while we recorded three-dimensional head kinematics and intramuscular EMG from six bilateral neck muscle pairs. We used a cross-validation-based stepwise regression to quantitatively examine the relationships between neck EMG and torsional head kinematics under three conditions: 1) unilateral INC stimulation (where the head rotated torsionally toward the side of stimulation); 2) corrective poststimulation movements (where the head returned toward upright); and 3) unilateral INC inactivation (where the head tilted toward the opposite side of inactivation). Our cross-validated results of corrective movements were slightly better than those obtained during unperturbed gaze movements and showed many more torsional terms, mostly related to velocity, although some orientation and acceleration terms were retained. In addition, several simplifying principles were identified. First, bilateral muscle pairs showed similar, but opposite EMG-torsional coupling terms, i.e., a change in torsional kinematics was associated with increased muscle activity on one side and decreased activity on the other side. s, whenever torsional terms were retained in a given muscle, they were independent of the inputs we tested, i.e., INC stimulation vs. corrective motion vs. INC inactivation, and left vs. right INC data. These findings suggest that, despite the complexity of the head-neck system, the brain can use a single, bilaterally coupled inverse model for torsional head control that is valid across different behaviors and movement directions. Combined with our previous data, these new data provide the terms for a more complete three-dimensional model of EMG: head rotation coupling for the muscles and gaze behaviors that we recorded.

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