Spatial deficits in visuomotor control along the body midline in a patient with optic ataxia

Performance of 200 children (5 groups, 4 to 12 yr.) in an experimental study of spatial development was analyzed in terms of hand preference and differences in laterality of response. In accord with the literature a cross-lateral inhibition effect was confirmed but there were marked differences between hands. The supposed ‘body midline’ seemed to offer more resistance to one hand than to the other. Alternative explanations are suggested.

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Binocular vision and the control of foot placement during walking in natural terrain

Scientific Reports ◽

10.1038/s41598-021-99846-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Kathryn Bonnen ◽

Jonathan S. Matthis ◽

Agostino Gibaldi ◽

Martin S. Banks ◽

Dennis M. Levi ◽

...

Keyword(s):

Binocular Vision ◽

Visual Function ◽

Visual Information ◽

Developmental Disorders ◽

Control Process ◽

Visuomotor Control ◽

The Body ◽

Foot Placement ◽

Sensory Uncertainty ◽

The Impact

AbstractCoordination between visual and motor processes is critical for the selection of stable footholds when walking in uneven terrains. While recent work (Matthis et al. in Curr Biol 8(28):1224–1233, 2018) demonstrates a tight link between gaze (visual) and gait (motor), it remains unclear which aspects of visual information play a role in this visuomotor control loop, and how the loss of this information affects that relationship. Here we examine the role of binocular information in the visuomotor control of walking over complex terrain. We recorded eye and body movements while normally-sighted participants walked over terrains of varying difficulty, with intact vision or with vision in one eye blurred to disrupt binocular vision. Gaze strategy was highly sensitive to the complexity of the terrain, with more fixations dedicated to foothold selection as the terrain became more difficult. The primary effect of increased sensory uncertainty due to disrupted binocular vision was a small bias in gaze towards closer footholds, indicating greater pressure on the visuomotor control process. Participants with binocular vision losses due to developmental disorders (i.e., amblyopia, strabismus), who have had the opportunity to develop alternative strategies, also biased their gaze towards closer footholds. Across all participants, we observed a relationship between an individual’s typical level of binocular visual function and the degree to which gaze is shifted toward the body. Thus the gaze–gait relationship is sensitive to the level of sensory uncertainty, and deficits in binocular visual function (whether transient or long-standing) have systematic effects on gaze strategy in complex terrains. We conclude that binocular vision provides useful information for locating footholds during locomotion. Furthermore, we have demonstrated that combined eye/body tracking in natural environments can be used to provide a more detailed understanding of the impact of a type of vision loss on the visuomotor control process of walking, a vital everyday task.

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Topography and receptive field organization of the body midline representation in the ventrobasal complex of the cat

Experimental Brain Research ◽

10.1007/bf00236234 ◽

1984 ◽

Vol 54 (2) ◽

Cited By ~ 14

Author(s):

P. Barbaresi ◽

F. Conti ◽

T. Manzoni

Keyword(s):

Receptive Field ◽

The Body ◽

Body Midline ◽

Ventrobasal Complex ◽

Field Organization ◽

Receptive Field Organization

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Instructions, Illusory Self-Tilt and the Rod-and-Frame Test

Quarterly Journal of Experimental Psychology ◽

10.1080/14640747908400715 ◽

1979 ◽

Vol 31 (1) ◽

pp. 155-165 ◽

Cited By ~ 40

Author(s):

Eric Sigman ◽

Donald R. Goodenough ◽

Michael Flannagan

Keyword(s):

Opposite Direction ◽

Test Performance ◽

The Body ◽

Body Midline ◽

Adjustment Error ◽

Gravitational Vertical ◽

Rod And Frame Test ◽

Rod And Frame

If an illusion of self-tilt is involved in rod-and-frame test performance, then instructions to adjust the rod to the body midline (egocentric instructions) should result in less rod adjustment error than the standard instructions for the rod-and-frame test to adjust the rod to the gravitational vertical. Two experiments were designed to examine this possibility. The results of the first experiment indicate that the tilted rod-and-frame display induces an illusion of self-tilt in the opposite direction. Significant differences between instructional conditions were found in the second experiment as expected. Other rod-and-frame studies are discussed in view of these findings.

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The Effect of Bilateral Isometric Forces in Different Directions on Motor Cortical Function in Humans

Journal of Neurophysiology ◽

10.1152/jn.00020.2010 ◽

2010 ◽

Vol 104 (6) ◽

pp. 2922-2931 ◽

Cited By ~ 18

Author(s):

Juliette A. Yedimenko ◽

Monica A. Perez

Keyword(s):

Primary Motor Cortex ◽

Index Finger ◽

Motor Evoked Potentials ◽

Short Interval ◽

The Body ◽

Body Midline ◽

Cortical Function ◽

Intracortical Circuits ◽

The Right ◽

Isometric Forces

The activity in the primary motor cortex (M1) reflects the direction of movements, but little is known about physiological changes in the M1 during generation of bilateral isometric forces in different directions. Here, we used transcranial magnetic stimulation to examine motor evoked potentials (MEPs), short-interval intracortical inhibition (SICI), and interhemispheric inhibition (IHI) in the left first dorsal interosseous (FDI) during isometric index finger abduction while the right index finger remained at rest or performed isometric forces in different directions (abduction or adduction) and in different postures (prone and supine). Left FDI MEPs were suppressed during bilateral compared with unilateral forces, with a stronger suppression when the right index finger force was exerted in the adduction direction regardless of hand posture. IHI targeting the left FDI increased during bilateral compared with unilateral forces and this increase was stronger during right index finger adduction despite the posture of the right hand. SICI decreased to a similar extent during both bilateral forces in both hand postures. Thus generation of index finger isometric forces away from the body midline (adduction direction), regardless of the muscle engaged in the task, down-regulates corticospinal output in the contralateral active hand to a greater extent than forces exerted toward the body midline (abduction direction). Transcallosal inhibition, but not GABAergic intracortical circuits, was modulated by the direction of the force. These findings suggest that during generation of bimanual isometric forces the M1 is driven by “extrinsic” parameters related to the hand action.

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Hand-Foot Coupling: An Advantage for Crossed Legs

Perception ◽

10.1177/0301006619832499 ◽

2019 ◽

Vol 48 (4) ◽

pp. 356-359

Author(s):

Alice M. Pearce ◽

Joshua S. Harvey ◽

Hannah E. Smithson ◽

Rebekah C. White

Keyword(s):

Postural Stability ◽

Anticipatory Postural Adjustments ◽

The Body ◽

Body Midline ◽

Contralateral Hemisphere ◽

Coupling Effects ◽

Full Account ◽

The Right ◽

Motor Actions ◽

Motor Programme

It is difficult to perform distinct, simultaneous motor actions with the ipsilateral hand and foot; for example, clockwise circles with the right hand and counter-clockwise circles with the right foot. By chance, we discovered that this hand-foot coupling task is easier when seated with legs crossed. We consider various explanations. First, that there are reduced demands on the contralateral hemisphere when the motor programme of the right foot is executed on the left side of the body. Second, that the legs-crossed scenario is easier because movements are symmetrical with respect to body midline. By considering related motor actions, we conclude that neither of these explanations provides a full account. Thus, we suggest a third explanation, which is that coupling effects are reduced by virtue of increased postural stability and reduced anticipatory postural adjustments.

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Crossing the Body Midline in Learning-Disabled and Normal Children

American Journal of Occupational Therapy ◽

10.5014/ajot.38.1.35 ◽

1984 ◽

Vol 38 (1) ◽

pp. 35-39 ◽

Cited By ~ 8

Author(s):

S. A. Cermak ◽

A. J. Ayres

Keyword(s):

Learning Disabled ◽

The Body ◽

Body Midline ◽

Normal Children

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S–R Compatibilities Depend on Eccentricity of Responding Hand

The Quarterly Journal of Experimental Psychology Section A ◽

10.1080/14640748908402365 ◽

1989 ◽

Vol 41 (2) ◽

pp. 263-272 ◽

Cited By ~ 17

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.

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