scholarly journals Attention and awareness: Representation of visuomotor space in split-brain patients

2019 ◽  
Author(s):  
Jill A. Dosso ◽  
Romeo Chua ◽  
Daniel J. Weeks ◽  
David J. Turk ◽  
Alan Kingstone
Keyword(s):  
Orthogonal Experiment ◽  
The Body ◽  
Hand Position ◽  
Contralateral Hemisphere ◽  
Position Information ◽  
Cortical Input ◽  
Left Hand ◽  
Split Brain ◽  
Visual Access ◽  
Contralateral Hand

Each cerebral hemisphere primarily controls and receives sensory input with regard to the contralateral hand. In the disconnected brain (split-brain), when the hands are uncrossed, direct visual access to each hand is available to the controlling (contralateral) hemisphere. However, when a hand crosses the midline, visual and tactile information regarding the hand are presented to different hemispheres. It is unknown how a contralateral hemi- sphere codes the position and orientation of a visually inaccessible hand in the discon- nected brain. The present work addresses this issue. We ask how each hemisphere represents “its” hand across hand positions that span the midline in the absence of cortical input from the contralateral hemisphere. In other words, when a hand is placed across the midline and is visually inaccessible, is it represented by the controlling hemisphere: (1) in accordance with its new position with respect to the body (e.g., a left hand “becomes” a right effector when it crosses the midline), (2) with left/right position information unal- tered (e.g., the left hand is represented as “left” regardless of its location), or (3) stripped of its location information altogether? The relationship between hand position and the spatial codes assigned to potential responses (an index of hand representation) was investigated in two split-brain patients using direct (Experiment 1) and orthogonal (Experiment 2) S-R compatibility paradigms. S-R compatibility effects in split-brain patients were consistent with those displayed by typical individuals. These findings suggest that position-based compatibility effects do not rely on cross-cortical connections. Rather, each hemisphere can accurately represent the full visuomotor space, a process that appears to be subserved by subcortical connections between the hemispheres.

A novel method for investigating the importance of visual feedback on somatosensation and bodily-self perception

2017 ◽  
Vol 16 (1) ◽  
pp. 185
Author(s):  
Mikkel Thøgersen ◽  
John Hansen ◽  
Herta Flor ◽  
Lars Arendt-Nielsen ◽  
Laura Petrini
Keyword(s):  
Visual Feedback ◽  
Mixed Reality ◽  
Visual Input ◽  
The Body ◽  
Phantom Limb ◽  
Hand Position ◽  
Self Perception ◽  
Left Hand ◽  
Novel Method ◽  
Relationship Of

AbstractAimsVisual feedback is hypothesized to play an important role in the phantom limb condition. In this study we attempt to create an illusory experimental model of phantom limb wherein this condition is simulated by removing the visual input from the upper limb in a group of intact participants. The aim of the study is to investigate the role of visual feedback on somatosensation, nociception and bodily-self perception.MethodsUsing a novel mixed reality (MR) system, the visual feedback of the left hand is removed in order to visually simulate a left hand amputation on 30 healthy participants (15 females). Using a within-subject design, three conditions are created: visual amputation condition (MR with no visual input); visual condition (MR with normal vision); and a baseline condition (no MR). Thermal detection and nociceptive thresholds using method of limits are measured. Proprioception of the visually amputated hand is investigated by probing the felt hand position on a proximal-distal axis from the body. Using a questionnaire the effects of the missing visual feedback on bodily self is assessed.ResultsThere was a clear drift in proprioception of the left hand in the proximal direction between the control and visual amputation condition (p <0.001). A decrease in cold detection was also significant between the control and visual amputation condition (p < 0.001). Finally, questions on perceptual experiences indicated that the observed proprioceptive retraction of the visually amputated hand was also felt by the participants.ConclusionsMissing visual feedback greatly influences the perception of the visually amputated arm underlining the importance of visual feedback. The observed proprioceptive retraction of the hand resembles the telescoping perceptions often reported by phantom limb patients. The novel method developed for this study, is a new tool to investigate the influence of visual feedback on the relationship of bodily-self and chronic pain.

scholarly journals Integration of Proprioceptive and Visual Position-Information: An Experimentally Supported Model

1999 ◽  
Vol 81 (3) ◽  
pp. 1355-1364 ◽  
Author(s):  
Robert J. van Beers ◽  
Anne C. Sittig ◽  
Jan J. Denier van der Gon
Keyword(s):  
Visual Information ◽  
The Body ◽  
The Other ◽  
Proprioceptive Information ◽  
Position Information ◽  
Left Hand ◽  
The Mean ◽  
The Right ◽  
Variable Errors ◽  
Available Information

Integration of proprioceptive and visual position-information: an experimentally supported model. To localize one’s hand, i.e., to find out its position with respect to the body, humans may use proprioceptive information or visual information or both. It is still not known how the CNS combines simultaneous proprioceptive and visual information. In this study, we investigate in what position in a horizontal plane a hand is localized on the basis of simultaneous proprioceptive and visual information and compare this to the positions in which it is localized on the basis of proprioception only and vision only. Seated at a table, subjects matched target positions on the table top with their unseen left hand under the table. The experiment consisted of three series. In each of these series, the target positions were presented in three conditions: by vision only, by proprioception only, or by both vision and proprioception. In one of the three series, the visual information was veridical. In the other two, it was modified by prisms that displaced the visual field to the left and to the right, respectively. The results show that the mean of the positions indicated in the condition with both vision and proprioception generally lies off the straight line through the means of the other two conditions. In most cases the mean lies on the side predicted by a model describing the integration of multisensory information. According to this model, the visual information and the proprioceptive information are weighted with direction-dependent weights, the weights being related to the direction-dependent precision of the information in such a way that the available information is used very efficiently. Because the proposed model also can explain the unexpectedly small sizes of the variable errors in the localization of a seen hand that were reported earlier, there is strong evidence to support this model. The results imply that the CNS has knowledge about the direction-dependent precision of the proprioceptive and visual information.

S–R Compatibilities Depend on Eccentricity of Responding Hand

1989 ◽  
Vol 41 (2) ◽  
pp. 263-272 ◽  
Author(s):  
Claire F. Michaels
Keyword(s):  
Reaction Times ◽  
The State ◽  
The Body ◽  
Body Midline ◽  
Hand Position ◽  
Finger Movement ◽  
Left Hand ◽  
Action System ◽  
Right Hand ◽  
The Right

Bauer and Miller (1982) demonstrated that when responding on the body midline with the right hand, subjects react faster when the pairing between horizontally oriented stimuli (an X to the left or right of fixation) and vertically oriented responses (an up or down finger movement) is left–down, right–up (“anti-clockwise”) but when responding with the left hand, the converse pairing was faster. The present experiments tested whether those preferences held for responses other than on the body midline. Unimanual reaction times for clockwise and anti-clockwise S–R pairings were determined for both hands at the midline and 30 and 60 cm to the left or right. Hand position determined both the direction and extent of the compatibility preference; at eccentric positions the right hand preferred clockwise pairings and the left anticlockwise, the converse of that found by Bauer and Miller. The results extend Bauer and Miller's finding, raise problems for theories of S–R compatibility, and further reveal that the state of the action system “sets up” perception.

scholarly journals Seeing the body produces limb-specific modulation of skin temperature

2014 ◽  
Vol 10 (4) ◽  
pp. 20140157 ◽  
Author(s):  
Renata Sadibolova ◽  
Matthew R. Longo
Keyword(s):  
Skin Temperature ◽  
Autonomic Control ◽  
The Body ◽  
The Other ◽  
Thermal Regulation ◽  
Somatosensory Processing ◽  
Left Hand ◽  
Right Hand ◽  
Contralateral Hand ◽  
Mirror Box

Vision of the body, even when non-informative about stimulation, affects somatosensory processing. We investigated whether seeing the body also modulates autonomic control in the periphery by measuring skin temperature while manipulating vision. Using a mirror box, the skin temperature was measured from left hand dorsum while participants: (i) had the illusion of seeing their left hand, (ii) had the illusion of seeing an object at the same location or (iii) looked directly at their contralateral right hand. Skin temperature of the left hand increased when participants had the illusion of directly seeing that hand but not in the other two view conditions. In experiment 2, participants viewed directly their left or right hand, or the box while we recorded both hand dorsum temperatures. Temperature increased in the viewed hand but not the contralateral hand. These results show that seeing the body produces limb-specific modulation of thermal regulation.

scholarly journals Bimanual coupling effect during a proprioceptive stimulation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Biggio ◽  
A. Bisio ◽  
F. Garbarini ◽  
Marco Bove
Keyword(s):  
Motor Imagery ◽  
Coupling Effect ◽  
Line Drawing ◽  
Proprioceptive Information ◽  
Muscle Vibration ◽  
Imagery Condition ◽  
Left Hand ◽  
Contralateral Hand ◽  
Bimanual Coupling ◽  
The Right

AbstractCircle-line drawing paradigm is used to study bimanual coupling. In the standard paradigm, subjects are asked to draw circles with one hand and lines with the other hand; the influence of the concomitant tasks results in two “elliptical” figures. Here we tested whether proprioceptive information evoked by muscle vibration inducing a proprioceptive illusion (PI) of movement at central level, was able to affect the contralateral hand drawing circles or lines. A multisite 80 Hz-muscle vibration paradigm was used to induce the illusion of circle- and line-drawing on the right hand of 15 healthy participants. During muscle vibration, subjects had to draw a congruent or an incongruent figure with the left hand. The ovalization induced by PI was compared with Real and Motor Imagery conditions, which already have proved to induce bimanual coupling. We showed that the ovalization of a perceived circle over a line drawing during PI was comparable to that observed in Real and Motor Imagery condition. This finding indicates that PI can induce bimanual coupling, and proprioceptive information can influence the motor programs of the contralateral hand.

The Effect of Head Tilt on Perception of Self-Orientation While in a Greater than One G Environment

1995 ◽  
Vol 5 (1) ◽  
pp. 1-17
Author(s):  
Tamara L. Chelette ◽  
Eric J. Martin ◽  
William B. Albery
Keyword(s):  
Dynamic Environment ◽  
Head Tilt ◽  
Nonlinear Function ◽  
Longitudinal Axis ◽  
Multiple Regression Model ◽  
The Body ◽  
Hand Position ◽  
Haptic Information ◽  
Perception Of Self ◽  
Constant Head

The effect of head tilt on the perception of self-orientation while in a greater than one G environment was studied in nine subjects using the Armstrong Laboratory Dynamic Environment Simulator. After a 12-s stabilization period at a constant head tilt and G level, subjects reported their perception of the horizon by placing their right hand in a position they believed to be horizontal. Head tilt conditions ranged from -30° to +45° pitch over each of three head yaw positions. G levels ranged from one to four and were in the longitudinal axis of the body (Gz). Hand position was recorded in both the pitch and roll body axes. A function of head tilt did improve the fit of a multiple regression model to the collected data in both the pitch and roll axes (P < .05). The best fit was accomplished with a nonlinear function of G and head pitch. When the head remained level but the environment tilted with respect to the G vector (at angles similar to those perceived during head tilt), subjects accurately reported the environmental tilt. Head tilt under G can result in vestibular-based illusionary perception of environmental tilt. Actual environmental tilt is accurately perceived due to added channels of haptic information.

scholarly journals VALENCE OF PREDICATES IN THE ACTIVE-PASSIVE TRANSFORMATION IN GERMAN AND UKRAINIAN

2020 ◽  
pp. 77-82
Author(s):  
Tsymbalista L.R.
Keyword(s):  
Sampling Method ◽  
Syntactic Structure ◽  
Hand Position ◽  
Continuous Sampling ◽  
Left Hand ◽  
Decisive Effect ◽  
Modern Fiction ◽  
The Subject ◽  
The Right

Валентність предиката має вирішальний вплив на структуру речення. Хоча активний і пасивний варіанти речення опису-ють одну й ту ж ситуацію, предикат проходить крізь трансформацію, яка тісно пов’язана з явищем валентності. У цій статті проаналізовано валентність предиката та її вплив на цю трансформацію у німецькій та українській мовах на прикладах із сучасної літератури.Мета. Метою статті є порівняння трансформації «актив – пасив» у німецькій та українській мовах та опис ролі валентності у цьому процесі.Методи. Для проведення дослідження було зібрано методом суцільної вибірки приклади пасивних конструкцій із сучас-них художніх текстів німецькою та українською мовами, які опісля було оброблено та проаналізовано з використанням типо-логічного, зіставного, описового методів, а також методу моделювання.Валентність предиката проявляється у його здатності формувати зв’язки з іншими елементами в реченні та дає змогу передбачити додаткові позиції у синтаксичній структурі речення, які можуть бути заповнені обов’язковими чи факультатив-ними компонентами. Для предиката властиві два типи валентності, які залежать від позиції поширювачів у реченні. Якщо лівобічну позицію переважно пов’язують із суб’єктом, то правобічна зазвичай стосується актантів з об’єктним, адресатним, локативним чи інструментальним значеннями.Результати. Зважаючи на те, що одна й та ж функція пасивних конструкцій у німецькій та українській мовах реалізується різними формами, валентні зміни у кожній з конструкцій мають свої особливості. Спільною рисою цих перетворень виступає зменшення облігаторних актантів на одну одиницю, яка може бути заповнена факультативно у разі комунікативної потреби у інформації про виконавця дії.Висновки. Можна зробити висновок, що валентність предиката є багатогранним феноменом, що підлягає впливу не лише формально-граматичних, а й семантико-синтаксичних чинників, а також мовленнєвої ситуації загалом. Відповідно, змін у валентності предикатів протягом трансформації з активу у пасив не можна уникнути. The valence of the predicate has a decisive effect on the structure of the sentence. Although the active and passive variant of the sentence describes the same situation, the predicate goes through a transformation that also has to do with valence. This article analyzes the valency of the predicate and its influence on such transformation in German and Ukrainian based on the examples from modern literature.Purpose. The purpose of the article is to compare the active-passive transformation in German and Ukrainian and to describe the role of valence in this process.Methods. For the research, we collected the examples of passive constructions from modern fiction in German and Ukrainian using the continuous sampling method, which were then processed and analyzed using typological, comparative, descriptive methods as well as the modelling method.The valence of the predicate verb shows in its ability to connect with other sentence elements and enables the prediction of the additional positions in the syntactic structure of the sentence, which can be supplemented by mandatory or optional components. The predicate is characterized by two types of valence, which depend on the position of the fillers in the sentence: the left-hand position is mainly connected the subject of the utterance, and the right-hand position has to do with actants which define object, addressee, location or have instrumental meaning.Results. Due to the fact that the same function of passive constructions in German and Ukrainian is realized in different forms, the valence changes in each of the constructions have their own features. A common feature of these transformations is the reduction of obligatory actants by one unit, which can be filled in optionally in case of communicative need for information about the performer of the action.Conclusions. We reach the conclusion that the valence of the predicate is a multilevel phenomenon that is influenced not only by formal grammatical but also by semantic and syntactic factors as well as the language situation in general. Accordingly, changes in the valence of predicates during the active-passive transformation are inevitable.

Bilateral Writing Ability, Cerebral Organization, and Hand Posture

1979 ◽  
Vol 49 (3) ◽  
pp. 867-870
Author(s):  
Allan L. Combs ◽  
Dana A. Beezley ◽  
Gary M. Prater ◽  
Gerald F. Henning ◽  
Rhonda F. Cottrell
Keyword(s):  
Hand Position ◽  
Hand Posture ◽  
Writing Ability ◽  
Left Hand ◽  
Left And Right ◽  
The Right

Among a group of 12 persons selected for the ability to write with ease with either hand, none were found to write using a hooked hand posture with either the right or left hand. Tests of verbal and manipulospatial ability indicated a normal balance of these two types of abilities, usually associated with the left and right hemispheres. Findings are discussed in terms of implications for cerebral organization and hand position in writing.

scholarly journals XIV.—Ancient Gold Ornaments: described by John Yonge Akerman, Esq. Secretary

Archaeologia ◽  
1853 ◽  
Vol 35 (1) ◽  
pp. 190-193
Author(s):  
John Yonge Akerman
Keyword(s):  
Light Chain ◽  
The Body ◽  
The Other ◽  
Asia Minor ◽  
Plate Viii ◽  
Left Hand ◽  
Small Loop ◽  
The Individual ◽  
The Right ◽  
Of Greece

With the exception of Figs. 1, 2, 3, the Gold Ornaments engraved in Plate VIII. have no reference whatever to each other. The first three were obtained by Viscount Strangford, Director of the Society, from a Greek priest at Milo, in the year 1820. Figs. 1 and 3 appear to have formed the ends of a light chain, and the other (fig. 2) to have been pendent by a small loop on the top of the head. The figure has unfortunately lost the feet and the left hand, but the other parts are perfect. The right hand is raised in an admonitory attitude. The forehead appears as if encircled with a wreath, while the body is crossed by what would seem to be intended for the tendril of a vine. The necklace was formerly in the collection of the late Mr. H. P. Borrell, of Smyrna, but I am informed by his brother, Mr. Maximilian Borrell, who now possesses it, that no record exists of its discovery, and that he cannot learn the name of the individual from whom it was purchased. It was well known that Mr. H. P. Borrell was in the habit of purchasing ancient coins, which were sent to him from all parts of Greece and Asia-Minor, and that many rare and unique specimens fell into his hands, of which he contributed descriptions in various volumes of the Numismatic Chronicle. The necklace may, therefore, have been included in one of these numerous consignments, and we can scarcely indulge the hope that the place of its discovery will ever be made known. As an example of ancient art, it may vie with the most elaborate and beautiful specimens of goldsmiths' work of any age or period. The details are wonderfully minute and delicate, even the backs of the button-like objects at the ends of the pendent cords being elaborately finished.

Fusion of Visual and Proprioceptive Information about Hand Position Prior to Movement

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 127-127
Author(s):  
M Desmurget ◽  
Y Rossetti ◽  
C Prablanc
Keyword(s):  
Visual Information ◽  
Human Subjects ◽  
Visual Presentation ◽  
Accurate Estimate ◽  
Open Loop ◽  
The Body ◽  
Hand Position ◽  
Proprioceptive Information ◽  
Movement Onset ◽  
Loop Condition

The problem whether movement accuracy is better in the full open-loop condition (FOL, hand never visible) than in the static closed-loop condition (SCL, hand only visible prior to movement onset) remains widely debated. To investigate this controversial question, we studied conditions for which visual information available to the subject prior to movement onset was strictly controlled. The results of our investigation showed that the accuracy improvement observed when human subjects were allowed to see their hand, in the peripheral visual field, prior to movement: (1) concerned only the variable errors; (2) did not depend on the simultaneous vision of the hand and target (hand and target viewed simultaneously vs sequentially); (3) remained significant when pointing to proprioceptive targets; and (4) was not suppressed when the visual information was temporally (visual presentation for less than 300 ms) or spatially (vision of only the index fingertip) restricted. In addition, dissociating vision and proprioception with wedge prisms showed that a weighed hand position was used to program hand trajectory. When considered together, these results suggest that: (i) knowledge of the initial upper limb configuration or position is necessary to plan accurately goal-directed movements; (ii) static proprioceptive receptors are partially ineffective in providing an accurate estimate of the limb posture, and/or hand location relative to the body, and (iii) visual and proprioceptive information is not used in an exclusive way, but combined to furnish an accurate representation of the state of the effector prior to movement.

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