The agents from this heterogeneous group have an effect on the repolarization, they prolong the duration of the action potential and the refractory period.
The prolongation of the action potential duration and refractory period, combined with the maintenance of normal conduction velocity, prevent re-entrant arrhythmias.
Although it limits the frequency of firing, the absolute refractory period ensures that the action potential moves in only one direction along an axon.
According to the hypothesis, targets presented during this refractory period can not trigger a release of norepinephrine, resulting in the attentional blink.