Publications by authors named "A S Litke"
Article Synopsis
- Neural interfaces can evoke specific neuron responses but often face challenges due to unpredictable nonlinearity when multiple electrodes are stimulated simultaneously.
- A biophysical model was created to study how retinal ganglion cells (RGCs) respond to this multi-electrode stimulation, and it was validated with real data from macaque retinas recorded through a microelectrode array.
- The model demonstrated that the positioning of electrodes significantly influences the response, showing that spikes can summate linearly or nonlinearly based on their proximity to the cell body and axon, supporting the hypothesis of multiple spike initiation sites.
Article Synopsis
- The study challenges the traditional view of retinal ganglion cells (RGCs) in the retina functioning mainly through simple center-surround spatial filtering, revealing instead a much higher functional diversity in primate RGC types, particularly in macaques and humans.
- Researchers identified 18-27 functional RGC types in primates, along with surprising non-classical receptive field structures and distinct responses to visual stimuli like natural movies.
- These findings suggest that these diverse RGC types have specialized roles in vision rather than just proportioning visual information at varying spatial scales.
Neural implants have the potential to restore lost sensory function by electrically evoking the complex naturalistic activity patterns of neural populations. However, it can be difficult to predict and control evoked neural responses to simultaneous multi-electrode stimulation due to nonlinearity of the responses. We present a solution to this problem and demonstrate its utility in the context of a bidirectional retinal implant for restoring vision.
View Article and Find Full Text PDFUAVs are increasingly being used in various domains, from personal and commercial applications to military operations. Ensuring the security and trustworthiness of UAV communications is crucial, and blockchain technology has been explored as a solution. However, privacy remains a challenge, especially in public blockchains.
View Article and Find Full Text PDFFixational eye movements alter the number and timing of spikes transmitted from the retina to the brain, but whether these changes enhance or degrade the retinal signal is unclear. To quantify this, we developed a Bayesian method for reconstructing natural images from the recorded spikes of hundreds of retinal ganglion cells (RGCs) in the macaque retina (male), combining a likelihood model for RGC light responses with the natural image prior implicitly embedded in an artificial neural network optimized for denoising. The method matched or surpassed the performance of previous reconstruction algorithms, and provides an interpretable framework for characterizing the retinal signal.
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