scholarly journals Rapid feedback corrections during a bimanual postural task

2013 ◽  
Vol 109 (1) ◽  
pp. 147-161 ◽  
Author(s):  
Mohsen Omrani ◽  
Jörn Diedrichsen ◽  
Stephen H. Scott
Keyword(s):  
Sensory Feedback ◽  
Specific Information ◽  
Spatial Average ◽  
Electromyographic Activity ◽  
Dependent Manner ◽  
Left Hand ◽  
Motor Physiology ◽  
The One ◽  
The Right ◽  
Online Feedback

An important observation in motor physiology is that even the fastest feedback responses can be modified in a task-dependent manner. However, whether or not such responses in one limb can be modulated based on online sensory feedback from other limbs is still unknown. We tested this using a bimanual postural control task, in which the two hands either controlled two separate cursors (double-cursor task) or a single cursor displayed at the spatial average between the hands (single-cursor task). In the first experiment, the two hands were symmetrically perturbed outwards. In the double-cursor task, the participants therefore had to return their hands to the targets, whereas in the single-cursor task no correction was necessary. Within 50 ms, the electromyographic activity showed significantly smaller responses in the single- compared with the double-cursor task. In the second experiment, the perturbation direction of the left hand (inward/outward) was randomized, such that participants could not preplan their response before perturbation onset. Results show that the behavior of the right arm in the one-cursor task depended on online feedback coming from the left arm: the muscular response was modulated within 75 ms based on directionally specific information of the left arm. These results suggest that sensory feedback from one limb can quickly modify the perturbation response of another limb in a task-dependent manner.

The State Policy towards the Homeless in Moldova between the ‘Left Hand’ and the ‘Right Hand’. The Case of Chișinău Shelter

Südosteuropa ◽  
2019 ◽  
Vol 67 (2) ◽  
pp. 175-195
Author(s):  
Petru Negură
Keyword(s):  
Homeless People ◽  
Severe Disabilities ◽  
The State ◽  
Small Scale ◽  
Left Hand ◽  
Right Hand ◽  
Binary Approach ◽  
The One ◽  
The Right ◽  
Depth Interviews

Abstract The Centre for the Homeless in Chișinău embodies on a small scale the recent evolution of state policies towards the homeless in Moldova (a post-Soviet state). This institution applies the binary approach of the state, namely the ‘left hand’ and the ‘right hand’, towards marginalised people. On the one hand, the institution provides accommodation, food, and primary social, legal assistance and medical care. On the other hand, the Shelter personnel impose a series of disciplinary constraints over the users. The Shelter also operates a differentiation of the users according to two categories: the ‘recoverable’ and those deemed ‘irrecoverable’ (persons with severe disabilities, people with addictions). The personnel representing the ‘left hand’ (or ‘soft-line’) regularly negotiate with the employees representing the ‘right hand’ (‘hard-line’) of the institution to promote a milder and a more humanistic approach towards the users. This article relies on multi-method research including descriptive statistical analysis with biographical records of 810 subjects, a thematic analysis of in-depth interviews with homeless people (N = 65), people at risk of homelessness (N = 5), professionals (N = 20) and one ethnography of the Shelter.

Over De Ontwikkeling Van Motorische Voorwaarden Voor Het Schrijven

1979 ◽  
Vol 7 ◽  
pp. 12-18
Author(s):  
A.J.W.M. Thomassen ◽  
J.L.H.M. Teulings
Keyword(s):  
Age Groups ◽  
Maximum Speed ◽  
Level Control ◽  
Motor Systems ◽  
Left Hand ◽  
Preferred Direction ◽  
Drawing Tasks ◽  
The One ◽  
The Right ◽  
Pure Motor

An experiment is reported in which writing and drawing tasks of two different types are presented to 26 subjects in four different age groups. These types of task are supposed to represent 'pure-motor' writing and drawing, requiring very little perceptual and higher control on the one hand, and 'cognitive' writing and drawing, requiring considerable perceptual control without allowing automation or lower-level control to take over, on the other. The tasks were performed both with the left hand and with the right. The variable into which the present paper looks specifically is the preferred direction followed in the production of curves, loops and contours. On the basis of discrepancies between data in the literature and earlier findings by the present authors, it was expected that the two types of task might reveal different motor systems, each displaying its own development with age. This expectation was confirmed. Writing tasks of the 'cognitive' type in general replicated the findings reported in the literature, viz., an increasing preference from the age of 5 or 6 for the counter-clockwise production of curves, loops and contours in copying or drawing single symbols and geometric figures. This preference appears to be independent of the writing hand. Writing tasks of the 'pure-motor' type, however, show a hand-dependent preference, which seems te develop for the left hand from a clockwise to a counterclockwise preference, and for the right hand from a counterclockwise to a clockwise writing bias. The latter appears in continuously drawing circles at maximum speed and in rapid continued scribbling, especially in the youngest (4;5) and oldest (adults) age groups. The feasibility and the possible role of the two independent motor systems, hypothesized to describe the results, are briefly mentioned.

scholarly journals Voluntary Actions Modulate Perception and Neural Representation of Action-Consequences in a Hand-Dependent Manner

2020 ◽  
Vol 30 (12) ◽  
pp. 6097-6107
Author(s):  
Batel Buaron ◽  
Daniel Reznik ◽  
Ro'ee Gilron ◽  
Roy Mukamel
Keyword(s):  
Visual Field ◽  
Motor System ◽  
Voluntary Movement ◽  
External Source ◽  
Neural Representation ◽  
Dependent Manner ◽  
Sensory Stimuli ◽  
Left Hand ◽  
Functional Laterality ◽  
The Right

Abstract Evoked neural activity in sensory regions and perception of sensory stimuli are modulated when the stimuli are the consequence of voluntary movement, as opposed to an external source. It has been suggested that such modulations are due to motor commands that are sent to relevant sensory regions during voluntary movement. However, given the anatomical-functional laterality bias of the motor system, it is plausible that the pattern of such behavioral and neural modulations will also exhibit a similar bias, depending on the effector triggering the stimulus (e.g., right/left hand). Here, we examined this issue in the visual domain using behavioral and neural measures (fMRI). Healthy participants judged the relative brightness of identical visual stimuli that were either self-triggered (using right/left hand button presses), or triggered by the computer. Stimuli were presented either in the right or left visual field. Despite identical physical properties of the visual consequences, we found stronger perceptual modulations when the triggering hand was ipsi- (rather than contra-) lateral to the stimulated visual field. Additionally, fMRI responses in visual cortices differentiated between stimuli triggered by right/left hand. Our findings support a model in which voluntary actions induce sensory modulations that follow the anatomical-functional bias of the motor system.

Time Course and Magnitude of Movement-Related Gating of Tactile Detection in Humans. II. Effects of Stimulus Intensity

2000 ◽  
Vol 84 (2) ◽  
pp. 863-875 ◽  
Author(s):  
Stephan R. Williams ◽  
C. Elaine Chapman
Keyword(s):  
Stimulus Intensity ◽  
Time Course ◽  
Human Subjects ◽  
Detection Performance ◽  
Electromyographic Activity ◽  
Dependent Manner ◽  
Significant Movement ◽  
Tactile Detection ◽  
The Right ◽  
Stimulus Localization

This study examined the effect of systematically varying stimulus intensity on the time course and magnitude of movement-related gating of tactile detection and scaling in 17 human subjects trained to perform a rapid abduction of the right index finger (D2) in response to a visual cue. Electrical stimulation was delivered to D2 at five different intensities. At the lowest intensity, approximately 90% of stimuli were detected at rest (1 × P90); four multiples of this intensity were also tested (1.25, 1.5, 1.75, and 2.0 × P90). At all intensities of stimulation, detection of stimuli applied to the moving digit was diminished significantly and in a time-dependent manner, with peak decreases occurring within ±12 ms of the onset of electromyographic activity in the first dorsal interosseous (25–45 ms before movement onset). Reductions in the proportion of stimuli detected were greatest at the lowest stimulus intensity and progressively smaller at higher intensities. No shift in the timing of the decreases in performance was seen with increasing intensity. Once the weakest intensity at which most stimuli were perceived during movement had been established (2 × P90), magnitude estimation experiments were performed using two stimulus intensities, 2 × P90 (5 subjects) and 3 × P90 (3 subjects). Significant movement-related decreases in estimated stimulus magnitude were observed at both intensities, the time course of which was similar to the time course of reductions in detection performance. As stimulus intensity increased, the magnitude of the movement-related decrease in scaling diminished. A model of detection performance that accurately described the effect of stimulus intensity and timing on movement-related reductions in detection was created. This model was then combined with a previous model that described the effects of stimulus localization and timing to predict detection performance at a given stimulation site, intensity, and time during movement. Movement-related gating of tactile perception represents the end result of movement-related effects on the transmission and subsequent processing of the stimulus. The combined model clearly defines many of the requirements that proposed physiological mechanisms of movement-related gating will have to fulfill.

Getting it Taped II

1971 ◽  
Vol 55 (391) ◽  
pp. 47-48
Author(s):  
J. Hlggins
Keyword(s):  
Magnetic Tape ◽  
Intermediate Stage ◽  
Actual Number ◽  
Constant Length ◽  
Left Hand ◽  
Run Off ◽  
Playing Time ◽  
The One ◽  
The Right ◽  
Revolution Counter

The standard tape–recorder consists outwardly of two spools on which the magnetic tape is wound, from the left to the right, between least and greatest radii of a and b. On my machine, a is about 1.05 in. and b is about 2.75 in. Apart from what is on the tape, the only indication at any intermediate stage as to how much playing time is still left is provided by a revolution counter geared to the left hand spool, the one which starts full and finishes empty. The numbers registered are about half the actual number of revolutions made on the left: this arrangement allows some 1400 revolutions to be registered by only three digits. It can be assumed that the tape is fed out at a constant length per unit of time: so the time still to run is proportional to the length still to run. If the total number of revolutions to run is N, how much of the tape ha3 been run off when the reading is n?

scholarly journals Multiple Congenital Bilateral Trigger Digits in a 2-Year-Old Child: Case Report

2013 ◽  
Vol 7 (1) ◽  
pp. 75-77 ◽  
Author(s):  
V De Luna ◽  
V Potenza ◽  
L Garro ◽  
P Farsetti ◽  
R Caterini
Keyword(s):  
Bacterial Infections ◽  
Rare Condition ◽  
Trigger Finger ◽  
Left Hand ◽  
Right Hand ◽  
History Of ◽  
One Year ◽  
The One ◽  
The Right

Trigger finger is a rare condition in children. In this paper, we report on a 2-year-old boy with multiple congenital bilateral trigger digits. The patient had no history of perinatal trauma, viral or bacterial infections, or metabolic disorders. The patient was treated with physiotherapy for one year. At the one-year follow-up, the boy presented with six trigger fingers (3 on the right hand, 3 on the left hand). Neither thumb was involved. The six trigger fingers were treated surgically: first, the right-hand trigger fingers and, six months later, those of the left hand. After each operation, a 4-week brace in extension was applied to the operated hand. The symptoms were completely resolved after surgical treatment. Many authors have recommended surgical release for the treatment of trigger finger in children; empirical treatment with physiotherapy may be an option when symptoms present or appear at an older age.

Hand Dominance, Attention, and the Choice between Responses

1978 ◽  
Vol 30 (3) ◽  
pp. 407-416 ◽  
Author(s):  
Patrick Rabbitt
Keyword(s):  
Attentional Bias ◽  
Attentional Biases ◽  
Horizontal Line ◽  
Hand Dominance ◽  
Left Hand ◽  
Left Handed ◽  
Hands On ◽  
Repeated Use ◽  
The One ◽  
The Right

Thirty pairs of matched right- and left-handed subjects carried out a serial C.RT task involving reaches between 2.4 cm square contact grids set at 2.4 cm intervals in a horizontal line. In one condition they responded with the right hand alone, in a second with the left and in a third they had to choose between hands on each trial responding to left side grids with the left hand and to right side grids with the right. All subjects took longer to respond when they had to choose between hands than when they used either hand alone. In the one-hand conditions neither group showed any effect of hand dominance. When choices had to be made between hands both groups responded faster with their dominant than with their nondominant hands. Analysis of the results was undertaken in terms of two hypothetical systems of instructions which might control machines designed to carry out similar tasks. It is concluded that in some tasks hand dominance can be described in terms of an attentional bias towards the field of operation of one effector rather than another. In the present task the effects of such possible attentional biases were shown not to interact with other effects, such as the facilitation of successive responses by repeated use of the same limb. These latter effects seem to depend on processes underlying execution of responses rather than choices between responding limbs.

scholarly journals Spatio-Temporal Prediction Modulates the Perception of Self-Produced Stimuli

1999 ◽  
Vol 11 (5) ◽  
pp. 551-559 ◽  
Author(s):  
Sarah-J. Blakemore ◽  
Chris D. Frith ◽  
Daniel M. Wolpert
Keyword(s):  
Sensory Feedback ◽  
Tactile Stimulus ◽  
Hand Movement ◽  
Tactile Sensation ◽  
Stimulus Movement ◽  
Left Hand ◽  
Temporal Prediction ◽  
Right Hand ◽  
Tactile Stimuli ◽  
The Right

We investigated why self-produced tactile stimulation is perceived as less intense than the same stimulus produced externally. A tactile stimulus on the palm of the right hand was either externally produced, by a robot or self-produced by the subject. In the conditions in which the tactile stimulus was self-produced, subjects moved the arm of a robot with their left hand to produce the tactile stimulus on their right hand via a second robot. Subjects were asked to rate intensity of the tactile sensation and consistently rated self-produced tactile stimuli as less tickly, intense, and pleasant than externally produced tactile stimuli. Using this robotic setup we were able to manipulate the correspondence between the action of the subjects' left hand and the tactile stimulus on their right hand. First, we parametrically varied the delay between the movement of the left hand and the resultant movement of the tactile stimulus on the right hand. Second, we implemented varying degrees of trajectory perturbation and varied the direction of the tactile stimulus movement as a function of the direction of left-hand movement. The tickliness rating increased significantly with increasing delay and trajectory perturbation. This suggests that self-produced movements attenuate the resultant tactile sensation and that a necessary requirement of this attenuation is that the tactile stimulus and its causal motor command correspond in time and space. We propose that the extent to which self-produced tactile sensation is attenuated (i.e., its tickliness) is proportional to the error between the sensory feedback predicted by an internal forward model of the motor system and the actual sensory feedback produced by the movement.

I 10, 1

1997 ◽  
Author(s):  
Roger Ling ◽  
Paul Arthur ◽  
Georgia Clarke ◽  
Estelle Lazer ◽  
Lesley A. Ling ◽  
...  
Keyword(s):  
The Other ◽  
Floor Level ◽  
Left Hand ◽  
The North ◽  
Street Corner ◽  
Side Walls ◽  
The One ◽  
North Wall ◽  
The Right ◽  
Distinguishing Features

This small corner house had acquired an irregular plan in its final phase, thanks, on the one hand, to the offset caused by the fountain at the street corner (Pls. 1, 2), and, on the other, to the small kitchen yard projecting westwards into the neighbouring property 1 10, 2-3. Its entrance, protected by a pent roof, the beam-holes for which (19 cm. in diameter) are visible beneath its modern replacement (Pl 3), was set at the right extremity of the north facade. It opened directly into the central hall (room 1), which can for convenience be called an ‘atrium’, though lacking the architectural pretensions and distinguishing features of traditional atria. Decorated with simple late Third Style paintings in a predominantly red, black, and yellow scheme, this ‘ atrium’ was around 3.50 m. high, and measured 3.75 m. by 5.35 m. on the ground. At its north end the east wall opened in a recess which may in an earlier phase have functioned as a latrine; its side walls preserve the grooves for a wooden shelf which, though rather high and deep (65 cm. above ground and 74 cm. deep), could possibly have been a lavatory seat. By the last period, however, this recess had been blocked by the construction of a stairway, and could only be entered, if it was still used at all, at a height of about 1 m. above floor level. Outside the recess, and also apparently put out of commission by the stairway, was a lararium, the sole relic of which was part of a painting on the north wall showing the Lares and a Genius; the left-hand Lar was missing and had almost certainly been clipped by the stairs. A socket in the wall just beneath the painting could have held a stone shelf for offerings, but is more likely to have been for a wooden beam which bridged the gap between the wall and the first three steps of the stairway, built in masonry against the east wall. The remaining steps, in wood, would have rested on this beam and risen westwards above the street door (Fig. 34 (S3)).

scholarly journals Ports minimization with mini-port and liver flexible retractor: an ergonomic and aesthetic alternative for single port in laparoscopic gastric bypass

2014 ◽  
Vol 27 (suppl 1) ◽  
pp. 77-79 ◽  
Author(s):  
Luiz Gonzaga de MOURA-JÚNIOR ◽  
Heládio Feitosa de CASTRO-FILHO ◽  
Francisco Heine Ferreira MACHADO ◽  
Rodrigo Feitosa BABADOPULOS ◽  
Francisca das Chagas FEIJÓ ◽  
...  
Keyword(s):  
Gastric Bypass ◽  
Single Port ◽  
Liver Parenchyma ◽  
Similar Time ◽  
Left Hand ◽  
Excluded Stomach ◽  
Liver Retractor ◽  
Aesthetic Aspect ◽  
The One ◽  
The Right

BACKGROUND: The laparoscopic access, with its classically known benefits, pushed implementation in other components, better ergonomy and aesthetic aspect. AIM: To minimize the number and diameter of traditional portals using miniport and flexible liver retractor on bariatric surgery. METHOD: This prospective study was used in patients with less than 45 kg/m2, with peripheral fat, normal umbilicus implantation, without previous abdominoplasties. Were used one 30o optical device with 5 mm in diameter, four accesses (one mini of 3 mm to the left hand of the surgeon, one of 5 mm to the right hand alternating with optics, one of 12 mm for umbilical for surgical maneuvers as dissection, clipping, in/out of gauze, and one portal of 5 mm for the assistant surgeon), resulting in a total of 25 mm linear incision; additionally, one flexible liver retractor (covered with a nelaton probe to protect the liver parenchyma, anchored in the right diaphragmatic pillar and going out through the surgeon left portal) to visualize the esophagogastric angle. RESULTS: In selected patients (48 operations), gastric bypass was performed at a similar time to the procedures with larger diameters (5 or 6 portals and 10 mm optics, with sum of linear incision of 42 mm) including oversuture line on excluded stomach, gastric tube and mesenteric closing. The non sutured portal of 3 mm and the two of 5 mm with subdermal sutures, were hardly visible in the folds of the skin; the one of 12 mm was buried inside the umbilicus or in the abdominoplasty incision. CONCLUSION: Minimizing portals is safe, effective, good ergonomic alternative with satisfactory aesthetic profile without need for specific instruments, new learning curve and limited movement of the instruments, as required by the single port.

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