EDUARDO CHICHILNISKY

..The functional importance of this structure is revealed by computational analysis of encoding and decoding, an approach that may be applicable to understanding the function of other neural circuits...

....

..These findings suggest that cortical neurons could filter their inputs on a time scale of tens of milliseconds, rather than relying on the precise times of individual input spikes, to sense motion most reliably...

..These findings suggest specific mechanistic asymmetries in retinal ON and OFF circuits and differences in visual performance on the basis of the activity of ON and OFF parasol cells...

..Advantages and disadvantages of the technique relative to classical approaches are discussed...

..The effect of background light on classification was largely explained by separate gain changes in increment and decrement cone signals...

..Neighboring BY cells received common but unequal inputs from one or more S cones. Inputs from individual S cones differed in strength, indicating different synaptic weights, and summed approximately linearly to control BY cell firing...

..Functionally defined subclasses of ON and OFF cells also exhibited asymmetric adaptation. These findings indicate that contrast adaptation differs in parallel retinal circuits that convey distinct visual signals to the brain...

..These findings reveal how faithfully the retinal population code conveys information about stimulus speed and the consequences for motion sensing in the brain...

..These measurements reveal computations in a neural circuit at the elementary resolution of individual neurons...

..These data suggest that direction selectivity in the retina is established largely independent of patterned activity and is therefore likely to emerge as a result of complex molecular interactions...

..These findings were consistent with a model in which firing probability was determined by a stimulus-driven free firing rate modulated by a recovery function representing the action potential absolute and relative refractory period...

..We review previous epiretinal stimulation studies and discuss our results in the context of 32 other publications, comparing threshold parameters and safety limits...

..The low-threshold, temporally precise, and spatially specific responses hold promise for the application of high-density arrays of small electrodes in epiretinal implants...

..These results show that the primate retina encodes light with an exquisitely coordinated array of RF shapes, illustrating a higher degree of functional precision in the neural circuitry than previously appreciated...

..In sum, large-scale synchronized firing in the entire population of ON-parasol cells appears to reflect simple neighbor interactions, rather than a unique visual signal or a highly redundant coding scheme...

..Thus, despite their distinctive morphology and chromatic properties, SBCs exhibit two features of other retinal ganglion cell types: center-surround antagonism and regular mosaic sampling of visual space...

..Finally, we apply these ideas to a recording from a guinea pig retinal ganglion cell and compare results to a simple linear decoder...

..Collectively, these results provide an overview of correlated firing across cell types in the primate retina, and constraints on the underlying mechanisms...

..This approach provides a way to define limits on the complexity of network interactions and thus may be relevant for probing the function of many neural circuits...

..These results extend the findings on distinctions between simple and complex cell chromatic tuning observed in previous studies in anesthetized monkeys...

..These findings indicate that important aspects of the cortical representation of color cannot be described by classical linear analysis, and reveal a possible neural correlate of perceptual color-luminance interactions...

..Third, rod input to SBCs may be the substrate for behavioral biases toward perception of blue at mesopic light levels...

..These findings suggest that high-resolution epiretinal prosthetic devices may be effective in treating vision loss resulting from photoreceptor degeneration...

....

..We interpret these asymmetries as differences in mechanisms of adaptation in the ON and OFF pathways, and suggest that they evolved to accommodate the range and physical sources of color signals in the two pathways...

..In related work, we apply these ideas to estimate the information rates between sensory stimuli and neural responses in experimental data (Shlens, Kennel, Abarbanel, & Chichilnisky, in preparation)...

..These results advance our understanding of the functional changes associated with retinal degeneration...

..In summary, knowing how the entire retinal network encodes the visual scene in spike trains is a key element in understanding the healthy visual system and designing prosthetic treatments for retinas damaged by disease. ..

..In summary, knowing the functional organization of parasol, midget and small bistratified cells is a key element in understanding the healthy visual system and designing prosthetic treatments for retinas damaged by disease. ..

....

..In summary, knowing the functional organization of parasol, midget and small bistratified cells is a key element in understanding the healthy visual system and designing prosthetic treatments for retinas damaged by disease. ..

....

..Aim 3. Does retinal signaling limit accuracy of behavioral and cortical motion sensing? This part will include psychophysical studies as well as correlation with recordings in MT obtained from other investigators. ..

..In summary, knowing how the entire retinal network encodes the visual scene in spike trains is a key element in understanding the healthy visual system and designing prosthetic treatments for retinas damaged by disease. ..