How Do Flanking Objects Affect Reaching and Grasping Behavior in Participants with Macular Disorders?

Pardhan, Shahina; Gonzalez-Alvarez, Carmen; Subramanian, Ahalya; Chung, Susana T. L.

doi:10.1167/iovs.12-9821

Cited by 6 publications

(5 citation statements)

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“…[14][15][16][17][18] A visual deficit can disrupt the performance of a voluntary motor action, as shown in previous studies. 12,13,19 For instance, some studies have shown impairments in initial movement planning and control in patients with glaucoma 20 and in agerelated macular degeneration, 12,13 or in grasping components in patients with amblyopia. 21 Kotecha et al (2009) reported atypical kinematic characteristics in patients with glaucoma compared to normally sighted people: slower reaction time, longer overall movement duration, low-velocity phase (suggesting a deficit in the grasping phase).…”

Section: Introductionmentioning

confidence: 99%

What is the Nature of the Reach-and-Grasp Deficit in Glaucoma?

Corveleyn

Lenoble

Rouland

et al. 2020

Journal of Glaucoma

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Section: Introductionmentioning

confidence: 99%

What is the Nature of the Reach-and-Grasp Deficit in Glaucoma?

Corveleyn

Lenoble

Rouland

et al. 2020

Journal of Glaucoma

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“…Although how crowding affects the identification of features has been studied extensively, few studies have investigated how crowding affects action such as grasping (Bulakowski, Post, & Whitney, 2009;Pardhan, Gonzalez-Alvarez, Subramanian, & Chung, 2012). When people use two fingers to grasp an object, the grip aperture first increases and then decreases as the fingers close in on the object.…”

Section: Introductionmentioning

confidence: 99%

The effects of shape crowding on grasping

2015

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Crowding refers to the deleterious effect of nearby objects on the identification of a target in the peripheral visual field. A recent study (Chen, Sperandio, & Goodale, 2015) showed that when a three-dimensional (3D) disk was crowded by disks of different sizes, participants could scale their grip aperture to the size of the target, even when they could not perceive its size. It is still unclear, however, whether or not grasping can also escape to some degree the crowding of other object features, such as shape. To test this, we presented 3D rectangular blocks in isolation or crowded by other blocks in the periphery. The target and flanking blocks had the same surface area but different dimensions. Participants were required either to grasp the target block across its width or to estimate its width. We found that, consistent with what we observed earlier with size, participants can also scale their grasp to the width of the target block even when they could not perceive its width. To further explore whether or not the effect of crowding on grasping depends on how proficient people are with their right hand, we had right-handed participants perform the same test but with their left hand. We found that left-hand grasping did not escape the crowding effect on shape perception at all. Taken together, our results suggest that people can also use invisible shape information to guide actions and that this ability depends on the proficiency of the action.

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“…[2][3][4] Reduced reach-to-grasp performance has been shown in normal subjects in whom central and PFLs have been simulated, [5][6][7][8] patients with AMD who have CFL, [9][10][11][12][13][14] and those with glaucoma with typical PFL deficits. 15 Timberlake et al 9 examined the effect of bilateral macular scotomas on reach-to-grasp performance and showed longer movement durations, lower maximum velocities, and longer visual reaction times than those of control subjects.…”

mentioning

confidence: 99%

“…Research from our own laboratory has shown how various parameters, including the duration of impairment, target contrast, and crowding of the objects influence reach-to-grasp performance in participants with AMD who have CFL deficits. [10][11][12][13][14] Kotecha et al 15 suggested a decreased reach-tograsp performance in patients suffering from glaucoma (PFL). Due to different methodologies, instruments, and procedures involved in these individual studies that investigated either CFL or PFL, it is difficult to directly compare the reach-to-grasp performance of participants with CFL versus those with PFL.…”

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confidence: 99%

A Comparison of Reach-to-Grasp and Transport-to-Place Performance in Participants With Age-Related Macular Degeneration and Glaucoma

Pardhan

Scarfe

Bourne

et al. 2017

Invest. Ophthalmol. Vis. Sci.

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Citation: Pardhan S, Scarfe A, Bourne R, Timmis M. A comparison of reachto-grasp and transport-to-place performance in participants with age-related macular degeneration and glaucoma. Invest Ophthalmol Vis Sci. 2017;58:156058: -156958: . DOI:10.1167 PURPOSE. To compare visually guided manual prehension in participants with primarily central field loss (CFL) due to age-related macular degeneration and peripheral visual field loss (PFL) due to glaucoma. This study extends current literature by comparing directly ''reach-to-grasp'' performance, and presents a new task of ''transport-to-place'' the object accurately to a new location. Data were compared to age-matched controls.METHODS. Three-dimensional motion data were collected from 17 glaucoma participants with PFL, 17 participants with age-related macular degeneration CFL and 10 age-matched control participants. Participants reached toward and grasped a cylindrical object (reach-to-grasp), and then transported and placed (transport-to-place) it at a different (predefined) peripheral location. Various kinematic indices were measured. Correlation analyses explored relationships between visual function and kinematic data. RESULTS.In the reach-to-grasp phase, CFL patients exhibited significantly longer movement and reaction times when compared to PFL participants and controls. Central field loss participants also took longer to complete the movement and made more online movements in the latter part of the reach. During the transport-to-place phase, CFL participants showed increased deceleration times, longer movement trajectory, and increased vertical wrist displacement. Central field loss also showed higher errors in placing the object at a predefined location. A number of kinematic indices correlated significantly to central visual function indices (P < 0.05).CONCLUSIONS. Significant differences in performance exist between CFL and PFL participants. Various indices correlated significantly with loss in acuity and contrast sensitivity (CS), suggesting that performance is more dependent on central visual function irrespective of underlying pathology.

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How Do Flanking Objects Affect Reaching and Grasping Behavior in Participants with Macular Disorders?

Cited by 6 publications

References 58 publications

What is the Nature of the Reach-and-Grasp Deficit in Glaucoma?

What is the Nature of the Reach-and-Grasp Deficit in Glaucoma?

The effects of shape crowding on grasping

A Comparison of Reach-to-Grasp and Transport-to-Place Performance in Participants With Age-Related Macular Degeneration and Glaucoma

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