Unsupervised learning of perceptual feature combinations
Fig 2
Functions used in model equations.
A: Neural activation, see Eq (2); we use a saturating function, where in case of small membrane potential (y) the activation v is zero, which is based on empirical observations, e.g., see. [20, 21]; B: Annealing function, which renders a close to zero annealing rate until threshold value va is reached, and afterwards increases abruptly, see Eqs (4) and (5); note that this function is additionally scaled by the annealing rate ρ in Eq (4).