Is Grasping Impaired in Hemispatial Neglect?

Patients with right unilateral cerebral stroke, four of which showed acute hemispatial neglect, and healthy aged-matched controls were tested for their ability to grasp objects located in either right or left space at near or far distances. Reaches were performed either in free vision or without visual feedback from the hand or target object. It was found that the patient group showed normal grasp kinematics with respect to maximum grip aperture, grip orientation, and the time taken to reach the maximum grip aperture. Analysis of hand path curvature showed that control subjects produced straighter right hand reaches when vision was available compared to when it was not. The right hemisphere lesioned patients, however, showed similar levels of curvature in each of these conditions. No behavioural differences, though, could be found between right hemisphere lesioned patients with or without hemispatial neglect on either grasp parameters, path deviation or temporal kinematics.

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The influence of target object shape on maximum grip aperture in human grasping movements

Experimental Brain Research ◽

10.1007/s00221-014-4046-2 ◽

2014 ◽

Vol 232 (11) ◽

pp. 3569-3578 ◽

Cited By ~ 8

Author(s):

Rebekka Verheij ◽

Eli Brenner ◽

Jeroen B. J. Smeets

Keyword(s):

Target Object ◽

Grip Aperture ◽

Object Shape ◽

Maximum Grip Aperture ◽

Maximum Grip

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Prehension and Perception of Size in Left Visual Neglect

Behavioural Neurology ◽

10.1155/2002/252405 ◽

2002 ◽

Vol 13 (1-2) ◽

pp. 3-15 ◽

Cited By ~ 17

Author(s):

R. D. McIntosh ◽

C. L. Pritchard ◽

H. C. Dijkerman ◽

A. D. Milner ◽

R. C. Roberts

Keyword(s):

Right Hemisphere ◽

Visual Neglect ◽

Grip Aperture ◽

Estimation Task ◽

Deceleration Phase ◽

Maximum Grip Aperture ◽

Patient Groups ◽

Visual Size ◽

Null Finding ◽

Maximum Grip

Right hemisphere damaged patients with and without left visual neglect, and age-matched controls had objects of various sizes presented within left or right body hemispace. Subjects were asked to estimate the objects’ sizes or to reach out and grasp them, in order to assess visual size processing in perceptual-experiential and action-based contexts respectively. No impairments of size processing were detected in the prehension performance of the neglect patients but a generalised slowing of movement was observed, associated with an extended deceleration phase. Additionally both patient groups reached maximum grip aperture relatively later in the movement than did controls. For the estimation task it was predicted that the left visual neglect group would systematically underestimate the sizes of objects presented within left hemispace but no such abnormalities were observed. Possible reasons for this unexpected null finding are discussed.

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On the Relation Between Object Shape and Grasping Kinematics

Journal of Neurophysiology ◽

10.1152/jn.00644.2003 ◽

2004 ◽

Vol 91 (6) ◽

pp. 2598-2606 ◽

Cited By ~ 83

Author(s):

Raymond H. Cuijpers ◽

Jeroen B. J. Smeets ◽

Eli Brenner

Keyword(s):

Principal Axis ◽

Grip Aperture ◽

Object Shape ◽

Hand Orientation ◽

Principal Axes ◽

Movement Distance ◽

Maximum Grip Aperture ◽

The Many ◽

Elliptical Cylinders ◽

Maximum Grip

Despite the many studies on the visual control of grasping, little is known about how and when small variations in shape affect grasping kinematics. In the present study we asked subjects to grasp elliptical cylinders that were placed 30 and 60 cm in front of them. The cylinders' aspect ratio was varied systematically between 0.4 and 1.6, and their orientation was varied in steps of 30°. Subjects picked up all noncircular cylinders with a hand orientation that approximately coincided with one of the principal axes. The probability of selecting a given principal axis was the highest when its orientation was equal to the preferred orientation for picking up a circular cylinder at the same location. The maximum grip aperture was scaled to the length of the selected principal axis, but the maximum grip aperture was also larger when the length of the axis orthogonal to the grip axis was longer than that of the grip axis. The correlation between the grip aperture— or the hand orientation—at a given instant, and its final value, increased monotonically with the traversed distance. The final hand orientation could already be inferred from its value after 30% of the movement distance with a reliability that explains 50% of the variance. For the final grip aperture, this was only so after 80% of the movement distance. The results indicate that the perceived shape of the cylinder is used for selecting appropriate grasping locations before or early in the movement and that the grip aperture and orientation are gradually attuned to these locations during the movement.

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The influence of object height on maximum grip aperture in empirical and modeled data.

Journal of Experimental Psychology Human Perception & Performance ◽

10.1037/a0035061 ◽

2014 ◽

Vol 40 (2) ◽

pp. 889-896 ◽

Cited By ~ 2

Author(s):

Svenja Borchers ◽

Rebekka Verheij ◽

Jeroen B. J. Smeets ◽

Marc Himmelbach

Keyword(s):

Grip Aperture ◽

Maximum Grip Aperture ◽

Maximum Grip

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Intentional Supernumerary Motor Phantom Limb after Right Cerebral Stroke: A Case Report

Case Reports in Neurology ◽

10.1159/000513302 ◽

2021 ◽

Vol 13 (1) ◽

pp. 251-258

Author(s):

Mai Yamada ◽

Yoshimi Sasahara ◽

Makiko Seto ◽

Akira Satoh ◽

Mitsuhiro Tsujihata

Keyword(s):

Right Hemisphere ◽

Premotor Cortex ◽

Brain Mri ◽

The Body ◽

Phantom Limb ◽

Cerebral Stroke ◽

Emission Computed Tomography ◽

Computed Tomography Images ◽

Intention To Move ◽

The Right

A 47-year-old right-handed man was admitted to our hospital for rehabilitation after right basal ganglion hematoma. On day 57, he noticed a supernumerary motor phantom limb (SPL) involving his right arm, originating at the level of the elbow. The most notable finding of his SPL was the motor characteristic. When the subject had the intention to move the upper paralyzed limb simultaneously with the trainer’s facilitating action, he said “there is another arm.” The intention to move the paralyzed arm alone or passive movement of the paralyzed arm did not induce the SPL. He showed a severe left sensorimotor impairment and mild hemineglect, but no neglect syndromes of the body (e.g., asomatognosia, somatoparaphrenia, personification and misoplegia, or anosognosia) were observed. Brain MRI demonstrated a hematoma in the right temporal lobe subcortex, subfrontal cortex, putamen, internal capsule, and thalamus. Single-photon emission computed tomography images showed more widespread hypoperfusion in the right hemisphere in comparison to the lesions on MRI. However, the premotor cortex was preserved. Our case is different from Staub’s case in that SPL was not induced by the intention to move the paralyzed limb alone; rather, it was induced when the patient intended to move the paralyzed limb with a trainer’s simultaneous facilitating action. The SPL may reflect that an abnormal closed-loop function of the thalamocortical system underlies the phantom phenomenon. However, despite the severe motor and sensory impairment, the afferent pathway from the periphery to the premotor cortex may have been partially preserved, and this may have been related to the induction of SPL.

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Are reaching and grasping effector-independent? Similarities and differences in reaching and grasping kinematics between the hand and foot

10.1101/2021.10.26.464901 ◽

2021 ◽

Author(s):

Yuqi Liu ◽

James Caracoglia ◽

Sriparna Sen ◽

Ella Striem-Amit

Keyword(s):

Peak Velocity ◽

Object Size ◽

Body Parts ◽

Acceleration Phase ◽

Grip Aperture ◽

Deceleration Phase ◽

Neural Representations ◽

Maximum Grip Aperture ◽

Similarities And Differences ◽

Maximum Grip

While reaching and grasping are highly prevalent manual actions, neuroimaging studies provide evidence that their neural representations may be shared between different body parts, i.e. effectors. If these actions are guided by effector-independent mechanisms, similar kinematics should be observed when the action is performed by the hand or by a cortically remote and less experienced effector, such as the foot. We tested this hypothesis with two characteristic components of action: the initial ballistic stage of reaching, and the preshaping of the digits during grasping based on object size. We examined if these kinematic features reflect effector-independent mechanisms by asking participants to reach toward and to grasp objects of different widths with their hand and foot. First, during both reaching and grasping, the velocity profile up to peak velocity matched between the hand and the foot, indicating a shared ballistic acceleration phase. Secondly, maximum grip aperture and time of maximum grip aperture of grasping increased with object size for both effectors, indicating encoding of object size during transport. Differences between the hand and foot were found in the deceleration phase and time of maximum grip aperture, likely due to biomechanical differences and the participants' inexperience with foot actions. These findings provide evidence for effector-independent visuomotor mechanisms of reaching and grasping that generalize across body parts.

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Improvement of hemispatial neglect with cold-water calorics: An electrophysiological test of the arousal hypothesis of neglect

Journal of the International Neuropsychological Society ◽

10.1017/s1355617797003949 ◽

1997 ◽

Vol 3 (4) ◽

pp. 394-402 ◽

Cited By ~ 15

Author(s):

H.J. STORRIE-BAKER ◽

S.J. SEGALOWITZ ◽

S.E. BLACK ◽

J.A.G. McLEAN ◽

N. SULLIVAN

Keyword(s):

Right Hemisphere ◽

Cold Water ◽

Eye Gaze ◽

Cortical Activation ◽

Central Position ◽

Hemispatial Neglect ◽

Caloric Stimulation ◽

Eeg Changes ◽

The Right ◽

Ice Water

Introducing ice-water into the left ear of right-brain-damaged patients attenuates unilateral neglect symptoms. By examining EEG changes over each hemisphere during this procedure, we were able to test a hypothesis concerning the mechanism of cold-water calorics and the attention–arousal hypothesis of hemispatial neglect. We present a case study of an 83-year-old woman with a massive right-hemisphere CVA exhibiting severe hemispatial neglect. Caloric stimulation produced a leftward eye deviation to central position, and a temporary partial remission of neglect symptoms. Significant changes in EEG activation indicated a central mechanism associated with the regularization of eye gaze. Caloric stimulation also produced a significant interaction between EEG frequency band and hemisphere, indicating that while both hemispheres increased in cortical activation, the right hemisphere increase was significantly greater. This supports the activation–arousal hypothesis of neglect over the mutual inhibition model. (JINS, 1997, 3, 394–402.)

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FOPR test: a virtual reality-based technique to assess field of perception and field of regard in hemispatial neglect

Journal of NeuroEngineering and Rehabilitation ◽

10.1186/s12984-021-00835-1 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Tae-Lim Kim ◽

Kwanguk Kim ◽

Changyeol Choi ◽

Ji-Yeong Lee ◽

Joon-Ho Shin

Keyword(s):

Virtual Reality ◽

Right Hemisphere ◽

Support Vector ◽

Hemispatial Neglect ◽

Stroke Patients ◽

Altman Plot ◽

Bland Altman Plot ◽

Visuospatial Function ◽

Conventional Tests ◽

The Right

Abstract Background We previously proposed a novel virtual reality-based method to assess human field of perception (FOP) and field of regard (FOR), termed the FOPR test. This study assessed the diagnostic validity of the FOPR test for hemispatial neglect (HSN). Methods We included 19 stroke patients with a lesion in the right hemisphere and with HSN (HSN+SS), 22 stroke patients with a lesion in the right hemisphere and without HSN (HSN−SS), and 22 healthy controls aged 19–65 years. The success rate (SR) and response time (RT) in the FOPR test for both FOP and FOR were assessed (FOP-SR, FOR-SR, FOP-RT, and FOR-RT, respectively). Using a Bland–Altman plot, agreements between the FOPR test and conventional tests were confirmed, and the FOPR test accuracy was verified using the support vector machine (SVM). Measured values were analysed using ANOVA and Kruskall–Wallis tests for group comparison. Results The Bland–Altman plot showed good agreement between FOPR test and conventional tests; individuals within 95% agreement limits were within the range of 94.8–100.0%. The SVM classification accuracy, using FOP and FOR variables from the left hemispace, ranged from 83.3 to 100.0% in a binary classification (HSN vs non-HSN). The FOPR test demonstrated differences in SR and RT for both FOP and FOR across the groups. Conclusion The FOPR test was valid for the HSN diagnosis and provided quantitative and intuitive information regarding visuospatial function. Furthermore, it might enhance our understanding of visuospatial function including HSN by applying the time relative component and concepts of perception and exploration, FOP and FOR. Trial registration: NCT03463122. Registered 13 March 2018, retrospectively registered.

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Some illusions are more inconsistent than others

10.31234/osf.io/7mxg8 ◽

2019 ◽

Author(s):

Jeroen B. J. Smeets ◽

Eli Brenner

Keyword(s):

Motion Aftereffect ◽

Apparent Size ◽

Ebbinghaus Illusion ◽

Reach To Grasp ◽

Grip Aperture ◽

Maximum Grip Aperture ◽

Pencil And Paper ◽

Maximum Grip

Illusions are characterized by inconsistencies. For instance, in the motion aftereffect, we see motion without an equivalent change in position. We used a simple pencil-and-paper experiment to determine whether illusions that influence an object’s apparent size give rise to equivalent changes in apparent positions along the object’s outline. We found different results for two equally strong size illusions. The Ebbinghaus illusion affected perceived positions in a way that was consistent with its influence on perceived size, but a modified diagonal illusion did not affect perceived positions. This difference between the illusions might explain why there are so many conflicting reports about the effects of size illusions on the maximum grip aperture during reach-to-grasp movements.

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Disruptions of the Human Connectome Associated With Hemispatial Neglect

Neurology ◽

10.1212/wnl.0000000000013050 ◽

2022 ◽

Vol 98 (2) ◽

pp. e107-e114

Author(s):

Sadhvi Saxena ◽

Zafer Keser ◽

Chris Rorden ◽

Leonardo Bonilha ◽

Julius Fridriksson ◽

...

Keyword(s):

White Matter ◽

Parietal Cortex ◽

Right Hemisphere ◽

Temporal Cortex ◽

Brain Regions ◽

Horizontal Line ◽

Hemispatial Neglect ◽

White Matter Tracts ◽

The Right ◽

Contralesional Side

Background and ObjectivesHemispatial neglect is a heterogeneous and complex disorder that can be classified by frame of reference for “left” vs “right,” including viewer-centered neglect (VCN, affecting the contralesional side of the view), stimulus-centered neglect (SCN, affecting the contralesional side of the stimulus, irrespective of its location with respect to the viewer), or both. We investigated the effect of acute stroke lesions on the connectivity of neural networks that underlie VCN or SCN.MethodsA total of 174 patients within 48 hours of acute right hemispheric infarct underwent a detailed hemispatial neglect assessment that included oral reading, scene copy, line cancellation, gap detection, horizontal line bisection tests, and MRI. Each patient's connectivity map was generated. We performed a linear association analysis between network connectivity strength and continuous measures of neglect to identify lesion-induced disconnections associated with the presence or severity of VCN and SCN. Results were corrected for multiple comparisons.ResultsAbout 42% of the participants with right hemisphere stroke had at least one type of neglect. The presence of any type of neglect was associated with lesions to tracts connecting the right inferior parietal cortex, orbitofrontal cortex, and right thalamus to other right-hemispheric structures. VCN only was strongly associated with tracts connecting the right putamen to other brain regions and tracts connecting right frontal regions with other brain regions. The presence of both types of neglect was most strongly associated with tracts connecting the right inferior and superior parietal cortex to other brain regions and those connecting left or right mesial temporal cortex to other brain regions.DiscussionOur study provides new evidence for the specific white matter tracts where disruption can cause hemispatial neglect in a relatively large number of participants and homogeneous time after onset. We obtained MRI and behavioral testing acutely, before the opportunity for rehabilitation or substantial recovery.Classification of EvidenceThis study provides Class II evidence that damage to specific white matter tracts identified on MRI are associated with the presence of neglect following right hemispheric stroke.

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