Publications by authors named "P Hottowy"
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.
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 PDFObjective: Neural interfaces are designed to evoke specific patterns of electrical activity in populations of neurons by stimulating with many electrodes. However, currents passed simultaneously through multiple electrodes often combine nonlinearly to drive neural responses, making evoked responses difficult to predict and control. This response nonlinearity could arise from the interaction of many excitable sites in each cell, any of which can produce a spike.
View Article and Find Full Text PDFLocal Field Potential (LFP), despite its name, often reflects remote activity. Depending on the orientation and synchrony of their sources, both oscillations and more complex waves may passively spread in brain tissue over long distances and be falsely interpreted as local activity at such distant recording sites. Here we show that the whisker-evoked potentials in the thalamic nuclei are of local origin up to around 6 ms post stimulus, but the later (7-15 ms) wave is overshadowed by a negative component reaching from cortex.
View Article and Find Full Text PDF. Bi-directional electronic neural interfaces, capable of both electrical recording and stimulation, communicate with the nervous system to permit precise calibration of electrical inputs by capturing the evoked neural responses. However, one significant challenge is that stimulation artifacts often mask the actual neural signals.
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