Interaction-driven modification of local response

For noninteracting units, a unit's response depends only upon its stimulus. A lattice model is constructed to show that even with nearest-neighbour communication, stimulus can remain a local function of equilibrium response-an inverse relationship. However, an extended model involving a feedback loop indicates that collective amplitudes can be expected to couple all response functions. Another model with extended spaces of stimulus and response brings in the necessity of stimulus-parametrized response functions to maintain a local inverse relationship.