Encoding and Decoding

  • Encoding solves “how does a stimulus cause a pattern of responses?” ().
  • Decoding solves “what do these responses tell us about the stimulus?” ().

Basic Coding Model

In the following context, represents signal, represents response, represents filter and represents nonlinear function.

Linear response

Temporal filtering: linear filters

Spatial filtering

Spatio-temporal filtering

Linear filter & nonlinearity

Feature Selection

We want to sample the responses of the system to many stimuli so we can characterize what it is about the input that triggers responses.

Variability

Kullback-Leibler divergence: difference between two probability distribution.

Tuning curve:

The Goodness measure between and :

Binominal spiking

Distribution:

Mean:

Variance:

Poisson spiking

Distribution:

Mean:

Variance:

Fano factor:

Interval distribution: