because then the transfer function produces no changes. Now with only one pattern stored (that being the pattern currently on the units):
sgn( wijai) | = sgn( aj ai ai) |
= sgn(n aj) |
|
= aj for all j |
Furthermore, provided at least half of the units in the starting pattern have the correct value sgn(neti) will give the correct value and the network will converge to the stored pattern - so the pattern is an attractor of the network.
In this simple case there are actually two attractors. The second one is the inverse of the stored pattern - the reverse state. If more than half of the units in the starting pattern are different from the stored pattern then the network will end up in the reverse state.