Figure 7.

In this example we show how local activity at cortical point-1 affects activity at a the more distal point-3 as inhibition strength at that point is reduced. The coupling strength between the two points was set to w_{e, 31} = w_{i, 31} = 0.02 and w_{e, 13} = w_{i, 13} = 0.02. In this condition, with the strength of the local feedback inhibition set at a value q_ei = −1.85, inputs from point-1 have a minimal effect on the output of point-3 (blue line). As q_ei is reduced at point-3, the firing rate gain of this point is increased. Note, however, that the value of q_ii was not changed. As explained in the text, functional coupling of two points by focal disinhibition only works when q_ei and q_ii are changed differentially, not in proportion.