  Certain biological systems exhibit both direct and retrograde propagating
wave signals, despite unidirectional neural coupling. However, there is no
model to explain this. Therefore, the underlying physics of reversing the
signal's direction for one-way coupling remains unclear. Here, we resolve this
issue using a Wilson-Cowan oscillators network. By analyzing the limit cycle
period of various coupling configurations, we determine that intrinsic
frequency differences among oscillators control wave directionality.
