Visual information about each character is obtained by sampling.
we represent each letter as a 26-dimensional vector, where a single element is 1 and the other 25 are zeros, and given this representation, foveal input for a letter is given as a sample from a 26-dimensional Gaussian with a mean equal to the letter's true identity and a diagonal covariance matrix Σ(ε) = λ (ε) −1/2 I.