p077fig02.28 Silent inhibition is replaced by hyperpolarization when the inhibitory saturating potential is smaller than the passive saturating potential.  Then an adpatation level is created that determines how big input ratios need to be to activate their cells.<BR>||  Weber Law and adaptation level.<BR>Hyperpolarization vs Silent inhibition<BR>d[dt: xi] = -A*xi +(B - xi)*Ii -(xi + C)*sum[k≠i: Ik]<BR>At equilibrium:<BR>0 = d[dt: xi] = -(A + Ii + )*xi +B*Ii -C*sum[k≠i: Ik]<BR>= -(A + I)*xi +(B + C)*Ii -C*I<BR>= -(A + I)*xi +(B + C)*I*[θi -C/(B + C)]<TABLE border="1"><TR><TD>xi = </td><TD>(B + C)*I/(A + I)* </td><TD>[θi </td><TD>-C/(B + C)]</td></tr><TR><TD></td><TD>Weber Law </td><TD>Reflectance </td><TD>Adaptation level</td></tr></table>