Exchange interactions in insulators can be understood in terms of the Andersen exchange picture in which the Hamiltonian has two contributions: (i) a kinetic term characterized by a hopping energy, t, between nearest neighbour Ni or Cu sites and (ii) a potential energy term, U, being the energy penalty for adding an additional electron on a given site. Within this picture, one can view antiferromagnetic exchange as arising from virtual hopping between sites. Experiments by Coldea et al on S=1/2 square latice antiferromagnet La2CuO4 showed that four-hop processes give rise to significant long range exchange interactions. Here we will search to see whether similar effect persist in S=1 analogue La2NiO4.