Distortion of Neural Signals by Spike Coding

13 years 4 months ago

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Analog neural signals must be converted into spike trains for transmission over electrically leaky axons. This spike encoding and subsequent decoding leads to distortion. We quantify this distortion by deriving approximate expressions for the mean square error between the inputs and outputs of a spiking link. We use integrate-and-ﬁre and Poisson encoders to convert naturalistic stimuli into spike trains and spike count and interspike interval decoders to generate reconstructions of the stimulus. The distortion expressions enable us to compare these spike coding schemes over a large parameter space. We verify that the integrate-and-ﬁre encoder is more effective than the Poisson encoder. The disparity between the two encoders diminishes as the stimulus coefﬁcient of variation (CV) increases, at which point the variability attributed to the stimulus overwhelms the variability attributed to Poisson statistics. When the stimulus CV is small, the interspike interval decoder is superio...

David H. Goldberg, Andreas G. Andreou

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