scholarly journals Focal Electrical Stimulation of Cortical Functional Networks

2020 ◽  
Vol 30 (10) ◽  
pp. 5532-5543 ◽  
Author(s):  
Jia Ming Hu ◽  
Mei Zhen Qian ◽  
Hisashi Tanigawa ◽  
Xue Mei Song ◽  
Anna Wang Roe
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Functional Organization ◽  
Visual Stimulation ◽  
Prosthetic Design ◽  
Single Feature ◽  
Selective Targeting ◽  
Visual Cortical ◽  
The Brain ◽  
Stimulation Of

Abstract Traditional electrical stimulation of brain tissue typically affects relatively large volumes of tissue spanning multiple millimeters. This low spatial resolution stimulation results in nonspecific functional effects. In addition, a primary shortcoming of these designs was the failure to take advantage of inherent functional organization in the cerebral cortex. Here, we describe a new method to electrically stimulate the brain which achieves selective targeting of single feature-specific domains in visual cortex. We provide evidence that this paradigm achieves mesoscale, functional network-specificity, and intensity dependence in a way that mimics visual stimulation. Application of this approach to known feature domains (such as color, orientation, motion, and depth) in visual cortex may lead to important functional improvements in the specificity and sophistication of brain stimulation methods and has implications for visual cortical prosthetic design.

scholarly journals Task-related activity in human visual cortex

PLoS Biology ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. e3000921
Author(s):  
Zvi N. Roth ◽  
Minyoung Ryoo ◽  
Elisha P. Merriam
Keyword(s):  
Visual Cortex ◽  
Optical Imaging ◽  
Visual Stimulation ◽  
Field Of View ◽  
Imaging Studies ◽  
Related Activity ◽  
Temporal Precision ◽  
Human Participants ◽  
Visual Cortical ◽  
The Brain

The brain exhibits widespread endogenous responses in the absence of visual stimuli, even at the earliest stages of visual cortical processing. Such responses have been studied in monkeys using optical imaging with a limited field of view over visual cortex. Here, we used functional MRI (fMRI) in human participants to study the link between arousal and endogenous responses in visual cortex. The response that we observed was tightly entrained to task timing, was spatially extensive, and was independent of visual stimulation. We found that this response follows dynamics similar to that of pupil size and heart rate, suggesting that task-related activity is related to arousal. Finally, we found that higher reward increased response amplitude while decreasing its trial-to-trial variability (i.e., the noise). Computational simulations suggest that increased temporal precision underlies both of these observations. Our findings are consistent with optical imaging studies in monkeys and support the notion that arousal increases precision of neural activity.

scholarly journals Dynamic Electrical Stimulation of Sites in Visual Cortex Produces Form Vision in Sighted and Blind Humans

2018 ◽  
Author(s):  
Michael S. Beauchamp ◽  
William Bosking ◽  
Ping Sun ◽  
Brett Foster ◽  
Soroush Niketeghad ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Visual Display ◽  
Current Steering ◽  
Form Vision ◽  
Visual Cortical ◽  
Stimulation Paradigm ◽  
Blind Humans ◽  
Field Location ◽  
Stimulation Of

AbstractVisual cortical prosthetics (VCPs) offer the promise of restoring sight to blind patients. Electrical stimulation of a single site in visual cortex can reliably produce a percept of a spot of light in a fixed visual field location, known as a phosphene. Researchers developing VCPs have assumed that multiple phosphenes produced by concurrent stimulation of multiple sites in visual cortex can combine to form a coherent form, like pixels in a visual display. However, existing data do not support this assumption. Therefore, we developed a novel stimulation paradigm for VCPs termed dynamic current steering in which the visual form to be conveyed is traced on the surface of visual cortex by electrically stimulating electrodes in a dynamic sequence. When tested in sighted and blind subjects, this method of stimulating visual cortex allowed for the immediate recognition of a variety of letter shapes without training and with high accuracy.One Sentence SummaryStimulating human visual cortex using dynamic patterns of activity allows both blind and sighted patients to perceive visual percepts of useful forms.

Effects of norepinephrine on the activity of visual neurons in the superior colliculus of the hamster

1999 ◽  
Vol 16 (3) ◽  
pp. 541-555 ◽  
Author(s):  
YI ZHANG ◽  
RICHARD D. MOONEY ◽  
ROBERT W. RHOADES
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Superior Colliculus ◽  
Visual Stimulation ◽  
Optic Chiasm ◽  
Evoked Responses ◽  
Visual Responses ◽  
Signal To Noise ◽  
Direct Stimulation ◽  
Stimulation Of

Single-unit recording and micropressure ejection techniques were used to test the effects of norepinephrine (NE) on the responses of neurons in the superficial layers (the stratum griseum superficiale and stratum opticum) of the hamster's superior colliculus (SC). Application of NE suppressed visually evoked responses by ≥30% in 75% of 40 neurons tested and produced ≥30% augmentation of responses in only 5%. The decrement in response strength was mimicked by application of the α2 adrenoceptor agonist, p-aminoclonidine, the nonspecific β agonist, isoproterenol, and the β1 agonist, dobutamine. These agents had similar effects on responses evoked by electrical stimulation of the optic chiasm and visual cortex. The α1 agonist, methoxamine, augmented the light-evoked responses of 53% of 49 SC cells by ≥30%, but had little effect on responses evoked by electrical stimulation of optic chiasm or visual cortex. The effects of adrenergic agonists upon the glutamate-evoked responses of SC cells that were synaptically “isolated” by concurrent application of Mg2+ were similar to those obtained during visual stimulation. Analysis of effects of NE on visually evoked and background activity indicated that application of this amine did not significantly enhance signal-to-noise ratios for most superficial layer SC neurons, and signal-to-noise ratios were in some cases reduced. These results indicate that NE acts primarily through α2 and β1 receptors to suppress the visual responses of SC neurons. Activation of either of these receptors reduces the responses of SC neurons to either of their two major visual inputs as well as to direct stimulation by glutamate, and it would thus appear that these effects are primarily postsynaptic.

scholarly journals Playing the electric light orchestra—how electrical stimulation of visual cortex elucidates the neural basis of perception

2015 ◽  
Vol 370 (1677) ◽  
pp. 20140206 ◽  
Author(s):  
Nela Cicmil ◽  
Kristine Krug
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Information Integration ◽  
Cortical Neurons ◽  
Extrastriate Cortex ◽  
Neural Basis ◽  
Electrical Microstimulation ◽  
Neuronal Mechanisms ◽  
Visual Cortical ◽  
Stimulation Of

Vision research has the potential to reveal fundamental mechanisms underlying sensory experience. Causal experimental approaches, such as electrical microstimulation, provide a unique opportunity to test the direct contributions of visual cortical neurons to perception and behaviour. But in spite of their importance, causal methods constitute a minority of the experiments used to investigate the visual cortex to date. We reconsider the function and organization of visual cortex according to results obtained from stimulation techniques, with a special emphasis on electrical stimulation of small groups of cells in awake subjects who can report their visual experience. We compare findings from humans and monkeys, striate and extrastriate cortex, and superficial versus deep cortical layers, and identify a number of revealing gaps in the ‘causal map′ of visual cortex. Integrating results from different methods and species, we provide a critical overview of the ways in which causal approaches have been used to further our understanding of circuitry, plasticity and information integration in visual cortex. Electrical stimulation not only elucidates the contributions of different visual areas to perception, but also contributes to our understanding of neuronal mechanisms underlying memory, attention and decision-making.

Ocular Dominance Peaks at Pinwheel Center Singularities of the Orientation Map in Cat Visual Cortex

1997 ◽  
Vol 77 (6) ◽  
pp. 3381-3385 ◽  
Author(s):  
Michael C. Crair ◽  
Edward S. Ruthazer ◽  
Deda C. Gillespie ◽  
Michael P. Stryker
Keyword(s):  
Visual Cortex ◽  
Visual Stimulation ◽  
Ocular Dominance ◽  
Normal Function ◽  
Functional Link ◽  
Orientation Map ◽  
Cat Visual Cortex ◽  
Visual Cortical ◽  
Continuous Orientation ◽  
Stimulation Of

Crair, Michael C., Edward S. Ruthazer, Deda C. Gillespie, and Michael P. Stryker. Ocular dominance peaks at pinwheel center singularities of the orientation map in cat visual cortex. J. Neurophysiol. 77: 3381–3385, 1997. In the primary visual cortex of monkey and cat, ocular dominance and orientation are represented continuously and simultaneously, so that most neighboring neurons respond optimally to visual stimulation of the same eye and orientation. Maps of stimulus orientation are punctuated by singularities referred to as “pinwheel centers,” around which all orientations are represented. Given that the orientation map is mostly continuous, orientation singularities are a mathematical necessity unless the map consists of perfectly parallel rows, and there is no evidence that the singularities play a role in normal function or development. We report here that in cats there is a strong tendency for peaks of ocular dominance to lie on the pinwheel center singularities of the orientation map. This relationship predicts but is not predicted by the tendencies, previously reported, for pinwheels to lie near the center lines of ocular dominance bands and for iso-orientation bands to cross ocular dominance boundaries at right angles. The coincidence of ocular dominance peaks with orientation singularities is likely to reflect a strong underlying functional link between the two visual cortical maps.

scholarly journals Visual Cortical Prosthesis : An Electrical Perspective

2020 ◽  
Author(s):  
Léo Pio-Lopez ◽  
Romanos Poulkouras ◽  
Damien Depannemaecker
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Electrode Array ◽  
Therapeutic Benefit ◽  
Point Of View ◽  
Technological Advances ◽  
Visual Cortical ◽  
Blind Individuals ◽  
New Generation ◽  
Stimulation Of

The electrical stimulation of the visual cortices has the potential to restore vision to blind individuals. Until now, the results of visual cortical prosthetics has been limited as no prosthesis has restored a full working vision but the field has shown a renewed interest these last years thanks to wireless and technological advances. However, several scientific and technical challenges are still open in order to achieve the therapeutic benefit expected by these new devices. One of the main challenges is the electrical stimulation of the brain itself. In this review, we analyze the results in electrode-based visual cortical prosthetics from the electrical point of view. We first briefly describe what is known about the electrode-tissue interface and safety of electrical stimulation. Then we focus on the psychophysics of prosthetic vision and the state-of-the-art on the interplay between the electrical stimulation of the visual cortex and phosphene perception. Lastly, we discuss the challenges and perspectives of visual cortex electrical stimulation and electrode array design to develop the new generation implantable cortical visual prostheses.

scholarly journals A vision prosthesis based on electrical stimulation of the primary visual cortex using epicortical microelectrodes

2020 ◽  
Author(s):  
Denise Oswalt ◽  
Projag Datta ◽  
Neil Talbot ◽  
Zaman Mirzadeh ◽  
Bradley Greger
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Microelectrode Array ◽  
Electrical Current ◽  
Electrical Currents ◽  
Chronic Electrical Stimulation ◽  
Multiple Array ◽  
Visual Cortical ◽  
Stimulation Of

Prostheses that can restore limited vision in the profoundly blind have been under investigation for several decades. Studies using epicortical macroelectrodes and intracortical microelectrodes have validated that electrical stimulation of primary visual cortical can serve as the basis for a vision prosthesis. However, neither of these approaches has resulted in a clinically viable vision prosthesis. Epicortical macroelectrodes required high levels of electrical current to evoke visual percepts, while intracortical microelectrodes faced challenges with longevity and stability. We hypothesized that epicortical microelectrodes could evoke visual percepts at lower currents than macroelectrodes and provide improved longevity and stability compared with intracortical microelectrodes. To test this hypotheses we implanted epicortical microelectrode arrays over the primary visual cortex of a nonhuman primate. Electrical stimulation via this array was used to evaluate the ability of epicortical microstimulation to evoke differentiable visual percepts. Visual percepts were evoked using the epicortical microelectrode array, and at electrical currents notably lower than those required to evoke visual percepts on macroelectrode arrays. The electrical current thresholds for evoking visual percepts on the epicortical microelectrode array were consistent across multiple array implants and over several months. Normal vision of light perception was not impaired by multiple array implants or chronic electrical stimulation, demonstrating that no gross visual deficit resulted from the experiments. We specifically demonstrate that epicortical microelectrode interfaces can serve as the basis for a vision prosthesis and more generally may provide an approach to evoking perception in multiple sensory modalities.

The functional organization of the brain of the cuttlefish Sepia officinalis

1961 ◽  
Vol 153 (953) ◽  
pp. 503-534 ◽  
Keyword(s):  
Electrical Stimulation ◽  
Functional Organization ◽  
Anterior Part ◽  
Visceral Ganglion ◽  
Optic Lobes ◽  
Basal Lobe ◽  
The Brain ◽  
Motor Centre ◽  
Stimulation Of

The functional organization of the brain of Sepia has been investigated by electrical stimulation. As a result several new divisions of the brain have been made. The pedal ganglion has been shown to consist of four parts: (1) the anterior chromatophore lobes innervating the skin and muscles of the anterior part of the head and arm s; (2) the anterior pedal lobe innervating the arms and tentacles; (3) the posterior pedal lobe innervating the funnel, collar and retractor muscles of the head; (4) the lateral pedal lobes innervating the muscles of the eyes and tissues of the orbits. The palliovisceral (or visceral) ganglion, apart from the magnocellular lobe demonstrated by Young (1939), is shown here to consist of (1) a central palliovisceral lobe innervating the mantle, funnel and viscera ; (2) a pair of lobes innervating the muscles of the fins; (3) a pair of posterior chromatophore lobes innervating the muscles of the chromatophores and skin of the mantle, fin and back of the head; (4) a pair of vasomotor lobes. Because of these new divisions the three main groupings of the suboesophageal neural tissue are now referred to as the anterior, middle and posterior suboesophageal masses corresponding to the old brachial, pedal and palliovisceral divisions. The suboesophageal centres are classified as lower motor centres and intermediate motor centres, depending on the kind of response they give to electrical stimulation and their peripheral connexions. In the supraoesophageal lobes, higher motor centres and silent areas are recognized. The silent areas include the vertical, superior frontal, subvertical, precommissural and dorsal basal lobes. Of the higher motor centres the anterior basal lobe is primarily concerned with the positioning of the head, arms and eyes, particularly during movements involving changes in direction while swimming. Such manoeuvres are brought about by the anterior basal lobe control over the fins and position of the funnel. The posterior basal lobe is here shown to consist of six main divisions: (1) the sub vertical lobe; (2) the dorsal basal lobes; (3) the precommissural lobe; (4) the medial basal lobe; (5) the lateral basal lobe; (6) the interbasal lobe. The medial, lateral and interbasal lobes are higher motor centres. The lateral and medial basal lobes control movements of the chromatophores and skin; the medial basal lobe controls swimming, breathing, fin movements and various visceral functions. The interbasal lobe controls the movements of the tentacles. The optic nerves and the optic lobes, at their periphery, are electrically inexcitable. Electrical stimulation of the centre of the optic lobes evokes all the responses that can be obtained from the other higher m otor centres. The results are discussed in term s of Sanders & Young’s (1940) physiological classification of the brain. A further category intermediate motor centre is recognized. Summary lists of the responses of each lobe are given on pages 516, 520, 525.

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