Discharge = electrical signalling release?

Context:
Communication within a species is most effective when it is exclusive, so it is beneficial to recognize signals from your own kind and exclude those made by others. Some fish species liv-ing in muddy rivers overcome the challenge of living in a low-visibility environment by electri-cal signaling. While studying the distinctive patterns of discharges from African electrical fish, Carlson et al. (p. 583) discovered that the evolution of key sensory processing regions in the brain allowed for rapid diversification in one group but was minimal in a closely related group that had diverged prior to the evolution of the sensory innovations. Species within the diversified clade possess receptor morphology that is more effi cient at transmitting and discerning complex electric signals than those of the less diverse group, implying that key innovations in brain devel-opment can lead to speciation because of improved perception and species recognition.