Dynamic Stimulation of Visual Cortex Produces Form Vision in Sighted and Blind Humans

Beauchamp, Michael S.; Oswalt, Denise; Park, Sun; Foster, Brett L.; Magnotti, John F.; Niketeghad, Soroush; Pouratian, Nader; Bosking, William H.; Yoshor, Daniel

doi:10.1016/j.cell.2020.04.033

Cited by 165 publications

(197 citation statements)

References 54 publications

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“…Importantly, the existence of cortical responses in the de-afferented visual cortex, as demonstrated in the present study, suggests that the LPZ is still to some degree operational. This finding is consequently in support of approaches restoring visual input to the cortex (Aguirre, 2017;Beauchamp et al, 2020;Chuang et al, 2014;Jutley et al, 2017;Sena and Lindsley, 2017;Venugopalan et al, 2016). High cost and limited availability makes the utility of MRI in routine clinical ophthalmological examinations less plausible.…”

Section: Clinical Relevance In the Context Of Emerging Therapeutic Insupporting

confidence: 54%

Functional dynamics of de-afferented early visual cortex in glaucoma

Prabhakaran

Al-Nosairy

Tempelmann

et al. 2020

Preprint

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AbstractfMRI studies in macular degeneration (MD) and retinitis pigmentosa (RP) demonstrated that responses in the lesion projection zones (LPZ) of V1 are task related, indicating significant limits of bottom-up visual system plasticity in MD and RP. In advanced glaucoma (GL), a prevalent eye disease and leading cause of blindness, the scope of visual system plasticity is currently unknown. We performed 3T fMRI in patients with extensive visual field defects due to GL (n=5), RP (n=2) and healthy controls (n=7; with simulated defects). Participants viewed contrast patterns drifting in 8 directions alternating with uniform gray and performed 3 tasks: (1) passive viewing (PV), (2) one-back task (OBT) and (3) fixation-dot task (FDT). During PV, they passively viewed the stimulus with central fixation, during OBT they reported the succession of the same two motion directions, and during FDT a change in the fixation color. In GL, LPZ responses of the early visual cortex (V1, V2 and V3) shifted from negative during PV to positive for OBT [p (corrected): V1(0.006); V2(0.04); V3(0.008)], while they were negative in the controls’ simulated LPZ for all stimulation conditions. For RP a similar pattern as for GL was observed. Consequently, activity in the de-afferented visual cortex in glaucoma is, similar to MD and RP, task-related. In conclusion, the lack of bottom-up plasticity appears to be a general feature of the human visual system. These insights are of importance for the development of treatment and rehabilitation schemes in glaucoma.HighlightsFunctional dynamics of early visual cortex LPZ depend on task demands in glaucomaBrain activity in deprived visual cortex suggests absence of large-scale remappingLimited scope of bottom-up plasticity is a general feature of human visual systemVisual system stability and plasticity is of relevance for therapeutic advances

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Section: Clinical Relevance In the Context Of Emerging Therapeutic Insupporting

confidence: 54%

Functional dynamics of de-afferented early visual cortex in glaucoma

Prabhakaran

Al-Nosairy

Tempelmann

et al. 2020

Preprint

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“…These results provide promising implications on the cortical prosthesis, which enables the reconstruction of visual experience, making use of intact neural tissue and preserved retinotopic organization. [60][61][62] Although many previous studies reported tactile-or auditoryevoked V1 responses in blind patients, [63][64][65][66][67][68] they did not assess the task dependency of responses. JMD patients have preserved visual fields, enabling us to assess the impact on intact feedforward signals.…”

Section: Report Discussionmentioning

confidence: 99%

V1 Projection Zone Signals in Human Macular Degeneration Depend on Task Despite Absence of Visual Stimulus

et al. 2021

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“…In addition, these large electrodes interacted with relatively large volumes of cortex (∼1 cm 3 ), resulting in very low spatial resolution of the perceived phosphenes (Christie et al, 2016;Niketeghad et al, 2019). These later findings have recently been confirmed by Beauchamp et al (2020), who implanted two different types of electrodes on the surface of the visual cortex of two blind individuals and found that when multiple electrodes were stimulated simultaneously, phosphenes fused into larger formless perceptions, making shape recognition impossible.…”

Section: Electrodes That Interact With the Brain In The Blind: Generamentioning

confidence: 84%

Toward Long-Term Communication With the Brain in the Blind by Intracortical Stimulation: Challenges and Future Prospects

2020

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The restoration of a useful visual sense in a profoundly blind person by direct electrical stimulation of the visual cortex has been a subject of study for many years. However, the field of cortically based sight restoration has made few advances in the last few decades, and many problems remain. In this context, the scientific and technological problems associated with safe and effective communication with the brain are very complex, and there are still many unresolved issues delaying its development. In this work, we review some of the biological and technical issues that still remain to be solved, including longterm biotolerability, the number of electrodes required to provide useful vision, and the delivery of information to the implants. Furthermore, we emphasize the possible role of the neuroplastic changes that follow vision loss in the success of this approach. We propose that increased collaborations among clinicians, basic researchers, and neural engineers will enhance our ability to send meaningful information to the brain and restore a limited but useful sense of vision to many blind individuals.

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Dynamic Stimulation of Visual Cortex Produces Form Vision in Sighted and Blind Humans

Cited by 165 publications

References 54 publications

Functional dynamics of de-afferented early visual cortex in glaucoma

Functional dynamics of de-afferented early visual cortex in glaucoma

V1 Projection Zone Signals in Human Macular Degeneration Depend on Task Despite Absence of Visual Stimulus

Toward Long-Term Communication With the Brain in the Blind by Intracortical Stimulation: Challenges and Future Prospects

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