= < = =

SlZ(t l ) = ABS1/ (A + So). (7) Equation (7) has the same form as a Weber law J(A + I)-I. The signal 8. is evaluated relative to the baseline So just as J is evaluated relative to I. This Weber law is due to slow intracellular adaptation of the transmitter gate to the input level through time. It is not due to fast intercellular lateral inhibition across space as in equation (2) of Grossberg [1981a].