Abstract People with paralysis express unmet needs for peer support, leisure activities and sporting activities. Many within the general population rely on social media massively multiplayer video games to address these needs. We developed a high-performance, finger-based brain–computer-interface system allowing continuous control of three independent finger groups, which thumb can be controlled in two dimensions, yielding total four degrees freedom. The was tested human research participant...

The visual message conveyed by a retinal ganglion cell (RGC) is often summarized its spatial receptive field, but in principle also depends on the responses of other RGCs and natural image statistics. This possibility was explored linear reconstruction images from four numerically-dominant macaque RGC types. Reconstructions were highly consistent across retinas. optimal filter for each – reflected statistics, resembled field only when nearby, same-type cells included. ON OFF largely...

People with paralysis express unmet needs for peer support, leisure activities, and sporting activities. Many within the general population rely on social media massively multiplayer video games to address these needs. We developed a high-performance finger brain-computer-interface system allowing continuous control of 3 independent groups 2D thumb movements. The was tested in human research participant over sequential trials requiring fingers reach hold targets, an average acquisition rate...

Responses of sensory neurons are often modeled using a weighted combination rectified linear subunits. Since these subunits cannot be measured directly, flexible method is needed to infer their properties from the responses downstream neurons. We present for maximum likelihood estimation by soft-clustering spike-triggered stimuli, and demonstrate its effectiveness in visual For parasol retinal ganglion cells macaque retina, estimated partitioned receptive field into compact regions, likely...

. Vision restoration with retinal implants is limited by indiscriminate simultaneous activation of many cells and cell types, which incompatible reproducing the neural code retina. Recent work has shown that primate ganglion (RGCs), transmit visual information to brain, can be directly electrically activated single-cell, single-spike, cell-type precision - however, this possibility never been tested in human In study we aim characterize, for first time, direct situ extracellular electrical...

Abstract Fixational eye movements alter the number and timing of spikes transmitted from retina to brain, but whether these changes enhance or degrade retinal signal is unclear. To quantify this, we developed a Bayesian method for reconstructing natural images recorded hundreds ganglion cells (RGCs) in macaque (male), combining likelihood model RGC light responses with image prior implicitly embedded an artificial neural network optimized denoising. The matched surpassed performance previous...

To restore and augment complex functions such as vision, electrical neural interfaces require the ability to selectively activate neurons at cellular resolution, a challenge given limited electrode density of typical interfaces. Current steering - passing current through multiple electrodes simultaneously target locations between could enhance but is intractable if all stimulation patterns must be tested exhaustively. Here, we develop experimentally validate framework for scalable...

A future artificial retina that can restore high acuity vision in blind people will rely on the capability to both read (observe) and write (control) spiking activity of neurons using an adaptive, bi-directional high-resolution device. Although current research is focused overcoming technical challenges building implanting such a device, exploiting its capabilities achieve more acute visual perception also require substantial computational advances. Using high-density large-scale recording...

Abstract Fixational eye movements alter the number and timing of spikes transmitted from retina to brain, but whether these changes enhance or degrade retinal signal is unclear. To quantify this, we developed a Bayesian method for reconstructing natural images recorded hundreds ganglion cells (RGCs) in macaque (male), combining likelihood model RGC light responses with image prior implicitly embedded an artificial neural network optimized denoising. The matched surpassed performance previous...

Retinal prostheses aim to restore visual perception in patients blinded by photoreceptor degeneration, stimulating surviving retinal ganglion cells (RGCs), causing them send artificial signals the brain. Present-day devices produce limited vision, part due indiscriminate and simultaneous activation of many RGCs different types that normally signal asynchronously. To improve we propose a closed-loop, cellular-resolution device automatically identifies properties nearby RGCs, calibrates its...

Keyboard typing with finger movements is a versatile digital interface for users diverse skills, needs, and preferences. Currently, such an does not exist people paralysis. We developed intracortical brain-computer (BCI) attempted flexion/extension of three groups on the right hand, or both hands, demonstrated its flexibility in two dominant paradigms. The first paradigm "point-and-click" typing, where BCI user selects one key at time using continuous real-time control, allowing selection...

ABSTRACT The functional organization of diverse retinal ganglion cell (RGC) types, which shapes the visual signal transmitted to brain, has been examined in many species. unique spatial, temporal, and chromatic properties numerically dominant RGC types macaque monkey retina are presumed most accurately model human vision. However, similarity between RGCs macaques humans only begun be tested, recent work suggests possible differences. Here, were using large-scale multi-electrode recordings...

Abstract How does the motor cortex combine simple movements (such as single finger flexion/extension) into complex hand gestures or playing piano)? Motor cortical activity was recorded using intracortical multi-electrode arrays in two people with tetraplegia they attempted single, pairwise and higher order movements. Neural for simultaneous largely aligned linear summation of corresponding movement activities, violations. First, neural normalized, preventing a large magnitude an increasing...

Intracortical brain computer interfaces (iBCIs) decode neural activity from the cortex and enable motor communication prostheses, such as cursor control, handwriting speech, for people with paralysis. This paper introduces a new iBCI prosthesis using 3D keyboard interface typing continuous, closed loop movement of multiple fingers. A participant-specific BCI prototype was developed BrainGate2 clinical trial participant (T5) recordings hand-knob area left premotor cortex. We assessed relative...

Objective: Retinal prostheses must be able to activate cells in a selective way order restore high-fidelity vision. However, inadvertent activation of far-away retinal ganglion (RGCs) through electrical stimulation axon bundles can produce irregular and poorly controlled percepts, limiting artificial In this work, we aim provide an algorithmic solution the problem detecting bundle with bi-directional epiretinal prostheses. Methods: The algorithm utilizes recordings determine current...

High-fidelity electronic implants can in principle restore the function of neural circuits by precisely activating neurons via extracellular stimulation. However, direct characterization individual electrical sensitivity a large population target neurons, to control their activity, be difficult or impossible. A potential solution is leverage biophysical principles infer stimulation from features spontaneous which recorded relatively easily. Here, this approach developed and its value for...

. Retinal implants are designed to stimulate retinal ganglion cells (RGCs) in a way that restores sight individuals blinded by photoreceptor degeneration. Reproducing high-acuity vision with these devices will likely require inferring the natural light responses of diverse RGC types implanted retina, without being able measure them directly. Here we demonstrate an inference approach exploits intrinsic electrophysiological features primate RGCs.

Future high-density and high channel count neural interfaces that enable simultaneous recording of tens thousands neurons will provide a gateway to study, restore augment functions. However, building such technology within the bit-rate limit power budget fully implantable device is challenging. The wired-OR compressive readout architecture addresses data deluge challenge interface using lossy compression at analog-to-digital interface. In this article, we assess suitability for several steps...

Eye-specific thalamic inputs converge in the primary visual cortex (V1) and form basis of binocular vision. For normal perceptions, such as depth stereopsis, binocularly matched orientation preference between two eyes is required. A critical period matching mice during development reported literature. Using a reaction diffusion model we present RF selectivity mouse V1 investigate period. At onset preferred orientations modeled cells are mostly mismatched mismatch decreases reaches levels...

ABSTRACT Retinal prostheses for treating incurable blindness are designed to electrically stimulate surviving retinal neurons, causing them send artificial visual signals the brain. However, electrical stimulation generally cannot precisely reproduce typical patterns of neural activity in retina. Therefore, an stimulus must be selected so as produce a response close possible desired response. This requires technique computing distance between and achievable that is meaningful terms signal...

Retinal implants are designed to restore vision people blinded by photoreceptor degeneration evoking spiking activity in surviving retinal ganglion cells (RGCs) and thus conveying artificial visual signals the brain. One approach is implant a high-density micro-electrode array on surface of retina apply electrical stimuli reproduce rich spatiotemporal patterns visually evoked RGC responses. However, this requires stimulation through multiple electrodes, which complicated non-linear...

Abstract Integration of rectified synaptic inputs is a widespread nonlinear motif in sensory neuroscience. We present novel method for maximum likelihood estimation subunits by soft-clustering spike-triggered stimuli. Subunits estimated from parasol ganglion cells recorded macaque retina partitioned the receptive field into compact regions, likely representing bipolar cell inputs. Joint clustering with multiple RGCs revealed shared neighboring cells, producing parsimonious population model....

Epiretinal implants are designed to restore visual function by direct stimulation of retinal ganglion cells (RGCs) with a multi-electrode array. However, the efficacy present-day epiretinal is limited indiscriminate, simultaneous activation many RGCs different types that normally convey distinct information, resulting in highly unnatural signals. Even high-density arrays laboratory setting, single-electrode often cannot target an individual cell selectively. A possible solution use spatially...