NEURONAL DYNAMICS I:ACTIVATIONS AND SIGNALS NEURONS AS FUNCTIONS The transduction description:a sigmoidal or S-shaped curve the logistic signal function: S(x)= +e-a =eS(1-S)>0 (c>0) dx The logistic signal function is sigmoidal and strictly increases for positive scaling constant c>0. 33 NEURONS AS FUNCTIONS The transduction description: a sigmoidal or S-shaped curve the logistic signal function: cx e S x − + = 1 1 ( ) ' = = cS(1− S)  0 (c  0) dx dS S The logistic signal function is sigmoidal and strictly increases for positive scaling constant c >0. NEURONAL DYNAMICS Ⅰ: ACTIVATIONS AND SIGNALS