Mapping the visual brain areas susceptible to phosphene induction through brain stimulation

Schaeffner, Lukas F.; Welchman, Andrew E.

doi:10.1007/s00221-016-4784-4

Cited by 31 publications

(25 citation statements)

References 60 publications

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“…The experiment was preceded by a short practice session (with no TMS) for each symmetry type, consisting of 20 trials (10 symmetric and 10 non-symmetric patterns). As expected given the stimulated regions (see Schaeffner and Welchman, 2017) and the TMS intensity used, none of our participants reported phosphene perception during the experiment.…”

Section: Methodssupporting

confidence: 82%

Not all visual symmetry is equal: Partially distinct neural bases for vertical and horizontal symmetry

2017

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Visual mirror symmetry plays an important role in visual perception in both human and animal vision; its importance is reflected in the fact that it can be extracted automatically during early stages of visual processing. However, how this extraction is implemented at the cortical level remains an open question. Given the importance of symmetry in visual perception, one possibility is that there is a network which extracts all types of symmetry irrespective of axis of orientation; alternatively, symmetry along different axes might be encoded by different brain regions, implying that there is no single neural mechanism for symmetry processing. Here we used fMRI-guided transcranial magnetic stimulation (TMS) to compare the neural basis of the two main types of symmetry found in the natural world, vertical and horizontal symmetry. TMS was applied over either right Lateral Occipital Cortex (LO), right Occipital Face Area (OFA) or Vertex while participants were asked to detect symmetry in low-level dot configurations. Whereas detection of vertical symmetry was impaired by TMS over both LO and OFA, detection of horizontal symmetry was delayed by stimulation of LO only. Thus, different types of visual symmetry rely on partially distinct cortical networks.

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Section: Methodssupporting

confidence: 82%

Not all visual symmetry is equal: Partially distinct neural bases for vertical and horizontal symmetry

2017

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“…So far, none of the microelectrode arrays have been or are planning to be implanted in the medial wall of the occipital lobe for two reasons: a) Risk of damage to the adjacent cortex and b) difficulty in wireless transmission when the receiver and transmitter coils are orthogonal [63,66,70]. Therefore, the occipito-dorso-lateral cortex is the preferred implantation site for microelectrode arrays and it might cover higher level visual areas (hMT+/ V5 and LOC) where the likelihood of phosphene induction is relatively lower [90]. Moreover, this can potentially limits the eccentricity of the phosphenes as the ventro-medial areas of the occipital cortex is associated with the periphery of the visual field [91,92].…”

Section: V1 Accessibilitymentioning

confidence: 99%

Brain Machine Interfaces for Vision Restoration: The Current State of Cortical Visual Prosthetics

Niketeghad

Pouratian

2019

Neurotherapeutics

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Loss of vision alters the day to day life of blind individuals and may impose a significant burden on their family and the economy. Cortical visual prosthetics have been shown to have the potential of restoring a useful degree of vision via stimulation of primary visual cortex. Due to current advances in electrode design and wireless power and data transmission, development of these prosthetics has gained momentum in the past few years and multiple sites around the world are currently developing and testing their designs. In this review, we briefly outline the visual prosthetic approaches and describe the history of cortical visual prosthetics. Next, we focus on the state of the art of cortical visual prosthesis by briefly explaining the design of current devices that are either under development or in the clinical testing phase. Lastly, we shed light on the challenges of each design and provide some potential solutions.

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“…At the end of each episode, participants were asked to rate their perception of flicker, phosphenes, and somatosensation under both head and wrist electrodes on a 0-9 scale with zero and nine indicating not at all and extremely strongly, respectively. Phosphenes were described to participants as flashes of light or distortions of the visual field (Schaeffner & Welchman, 2017, Marg & Rudiak, 1994. Flickers were described as changes in brightness.…”

Section: Phosphene and Somatosensation Control Studymentioning

confidence: 99%

Theta Phase-dependent Modulation of Perception by Concurrent Transcranial Alternating Current Stimulation and Periodic Visual Stimulation

Somer

Allen

Brooks

et al. 2020

Journal of Cognitive Neuroscience

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Sensory perception can be modulated by the phase of neural oscillations, especially in the theta and alpha ranges. Oscillatory activity in the visual cortex can be entrained by transcranial alternating current stimulation (tACS) as well as periodic visual stimulation (i.e., flicker). Combined tACS and visual flicker stimulation modulates BOLD response, and concurrent 4-Hz auditory click train, and tACS modulate auditory perception in a phase-dependent way. In this study, we investigated whether phase synchrony between concurrent tACS and periodic visual stimulation (i.e., flicker) can modulate performance on a visual matching task. Participants completed a visual matching task on a flickering visual stimulus while receiving either in-phase (0°) or asynchronous (180°, 90°, or 270°) tACS at alpha or theta frequency. Stimulation was applied over either occipital cortex or dorsolateral pFC. Visual performance was significantly better during theta frequency tACS over the visual cortex when it was in-phase (0°) with visual stimulus flicker, compared with antiphase (180°). This effect did not appear with alpha frequency flicker or with dorsolateral pFC stimulation. Furthermore, a control sham group showed no effect. There were no significant performance differences among the asynchronous (180°, 90°, and 270°) phase conditions. Extending previous studies on visual and auditory perception, our results support a crucial role of oscillatory phase in sensory perception and demonstrate a behaviorally relevant combination of visual flicker and tACS. The spatial and frequency specificity of our results have implications for research on the functional organization of perception.

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Mapping the visual brain areas susceptible to phosphene induction through brain stimulation

Cited by 31 publications

References 60 publications

Not all visual symmetry is equal: Partially distinct neural bases for vertical and horizontal symmetry

Not all visual symmetry is equal: Partially distinct neural bases for vertical and horizontal symmetry

Brain Machine Interfaces for Vision Restoration: The Current State of Cortical Visual Prosthetics

Theta Phase-dependent Modulation of Perception by Concurrent Transcranial Alternating Current Stimulation and Periodic Visual Stimulation

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