The Pointing Errors in Optic Ataxia Reveal the Role of “Peripheral Magnification” of the PPC

Vindras, Philippe; Blangero, Annabelle; Ota, Hisaaki; Reilly, Karen T.; Rossetti, Yves; Pisella, Laure

doi:10.3389/fnint.2016.00027

Cited by 16 publications

(15 citation statements)

References 79 publications

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“…Additionally, greater severity of optic ataxia (Perenin & Vighetto, 1988) was observed in patients with left hemisphere injures. In particular, most patients with optic ataxia after a left hemisphere lesion have displayed a hand effect (errors when pointing with their contralesional hand) as well as a contralateral field effect (errors when pointing to stimuli in the contralesional visual hemifield) (Vindras et al, 2016), whereas patients with a right hemisphere lesion showed a milder version of optic ataxia with only a field effect (Perenin & Vighetto, 1988). TC’s deficit is consistent with the non-dichotomous specialization of the left hemisphere in visuomotor computations.…”

Section: Discussionmentioning

confidence: 99%

Unilateral Resection of Both Cortical Visual Pathways Alters Action but not Perception

Ahmad

Behrmann

et al. 2021

Preprint

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The human cortical visual system consists of two major pathways, a ventral pathway that subserves perception and a dorsal pathway that subserves visuomotor control. These pathways follow dissociable developmental trajectories, and, accordingly, might be differentially susceptible to neurodevelopmental disorders or injuries. Previous studies have found that children with cortical resections of the ventral visual pathway retain largely normal visuoperceptual abilities. Whether visually guided actions, supported by computations carried out by the dorsal pathway, follow a similar pattern remains unknown. To address this question, we examined visuoperceptual and visuomotor behaviors in a pediatric patient, TC, who underwent a cortical resection that included portions of the left ventral and dorsal pathways. We collected data when TC used her right and left hands to perceptually estimate the width blocks that varied in width and length, and, separately, to grasp the same blocks. Her perceptual estimation performance was comparable to that of controls, independent of the hand used. In contrast, relative to controls, she showed reduced visuomotor sensitivity to object shape and this was more evident when she grasped the objects with her contralesional right hand. These results provide evidence for a striking difference in the reorganization profiles of the two visual pathways. This difference supports the notion that the two pathways exhibit differential susceptibility to neurodevelopmental disorders.

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Section: Discussionmentioning

confidence: 99%

Unilateral Resection of Both Cortical Visual Pathways Alters Action but not Perception

Ahmad

Behrmann

et al. 2021

Preprint

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“…The effect of changing the perception angle by 20 • and 40 • to the right on the dart throwing results can manifest itself in a similar way with dysfunction of somato-spatial synthesis while correlating the object's location with the respect to one's body and constructing a corresponding action program. For example, a mismatch of visual and proprioceptive information is observed in patients with optic ataxia associated with a dysfunction of the parieto-occipital junction [47]. Conducting cognitive diagnostics in VR or cognitive rehabilitation in VR by using Vicariation or by restructuring functional systems, without taking into account the factor of perception distortion of the perspective and body proportions, can produce an inadequate assessment on the degree of cognitive dysfunction.…”

Section: Discussionmentioning

confidence: 99%

Motor Program Transformation of Throwing Dart from the Third-Person Perspective

et al. 2020

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The perspective of perceiving one’s action affects its speed and accuracy. In the present study, we investigated the change in accuracy and kinematics when subjects throw darts from the first-person perspective and the third-person perspective with varying angles of view. To model the third-person perspective, subjects were looking at themselves as well as the scene through the virtual reality head-mounted display (VR HMD). The scene was supplied by a video feed from the camera located to the up and 0, 20 and 40 degrees to the right behind the subjects. The 28 subjects wore a motion capture suit to register their right hand displacement, velocity and acceleration, as well as torso rotation during the dart throws. The results indicated that mean accuracy shifted in opposite direction with the changes of camera location in vertical axis and in congruent direction in horizontal axis. Kinematic data revealed a smaller angle of torso rotation to the left in all third-person perspective conditions before and during the throw. The amplitude, speed and acceleration in third-person condition were lower compared to the first-person view condition, before the peak velocity of the hand in the direction toward the target and after the peak velocity in lowering the hand. Moreover, the hand movement angle was smaller in the third-person perspective conditions with 20 and 40 angle of view, compared with the first-person perspective condition just preceding the time of peak velocity, and the difference between conditions predicted the changes in mean accuracy of the throws. Thus, the results of this study revealed that subject’s localization contributed to the transformation of the motor program.

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“…Attentional disorders, for example, clinical spatial neglect, have been associated with lesions in the right TPJ (VAN) [11,12] but not with exclusive lesions in the IPS/SPL (DAN). Instead, clinical examination of patients with IPS/SPL lesions often reveals optic ataxia, a neurological deficit in which patients have no primary perceptual or motor deficits but present difficulties in responding to objects in the contralesional peripheral visual field [13][14][15][16][17][18][19][20], and in fast visuomotor transformations known to depend on interactions between the occipito-parietal region and the dorsal premotor and primary motor cortices (e.g., [21][22][23][24][25][26][27][28][29][30]). Interestingly, close examination of patients with focal IPS/SPL lesions and without clinical neglect syndrome, for example, by using briefly flashed stimuli, sometimes reveals attentional difficulties in the form of sub-clinical visual detection and discrimination deficits that are specific to covert endogenous orienting in the contralesional peripheral visual field [31][32][33][34][35][36].…”

Section: Introductionmentioning

confidence: 99%

Single-Case Neuropsychological Assessment of a Patient with a Posterior Parietal Lesion Using Behavioral Testing and Resting-State fMRI

Martín-Arévalo¹,

Guedj²,

Cotton³

et al. 2021

obm neurobiol

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This study integrated functional connectivity measures using resting-state fMRI and behavioral data from a single-case observation of patient (PER) one year after right-hemispheric hemorrhage in the intraparietal sulcus and superior parietal lobule (IPS/SPL). PER showed no sign of clinical neglect. Her behavioral performance in the visuo-manual pointing task and in the letter discrimination task under conditions of endogenous and exogenous attentional cueing was compared between the left (affected) and right (unaffected/control) peripheral visual fields. The resting-state fMRI demonstrated an imbalance between the right and left hemispheric frontoparietal functional connectivity within the dorsal attentional and motor networks. Although the frontal and occipital cortices were not structurally damaged, specific fronto-occipital functional connectivity was imbalanced, which was strongly associated with the behavioral changes. First, the activity in the right frontal eye field showed weaker correlations with the activity in the right inferior occipital area compared to the correlation with the activity in the left inferior occipital area. This imbalanced fronto-occipital functional connectivity was accompanied by a specific impairment in endogenous covert attention in the left visual field. Second, the activity within M1 in both hemispheres showed weaker correlations with the activity of the right cuneus compared to the correlation with the activity in the left cuneus. The imbalanced fronto-occipital functional connectivity was associated with the impairment of the reaching movement of the left and right hands towards the left visual field (optic ataxia). Altogether, our results showed that a lesion to the posterior parietal cortex affects the relationship between distal regions underlying the sensorimotor and attentional abilities

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The Pointing Errors in Optic Ataxia Reveal the Role of “Peripheral Magnification” of the PPC

Cited by 16 publications

References 79 publications

Unilateral Resection of Both Cortical Visual Pathways Alters Action but not Perception

Unilateral Resection of Both Cortical Visual Pathways Alters Action but not Perception

Motor Program Transformation of Throwing Dart from the Third-Person Perspective

Single-Case Neuropsychological Assessment of a Patient with a Posterior Parietal Lesion Using Behavioral Testing and Resting-State fMRI

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