A stable limit cycle (LC) generates a closed trajectory in the fixed reference frame . (a) A membrane potential perturbation moves the figurative point from the unperturbed LC to . The tangent projection of the phase space perturbation is and represents an instantaneous geometric phase jump that corresponds to a temporal phase resetting. The normal projection of is and it relaxes back to the unperturbed limit cycle producing an additional geometric phase displacement that translates into a phase resetting. After a time , the figurative point would have traveled to along the unperturbed LC whereas the perturbed figurative point reached . The normal distance between the two end points is and the corresponding tangent displacement is the geometric phase resetting, [30], which corresponds to a (temporal) phase resetting measured by . (b) In the absence of any coupling between the normal and tangent directions of the LC, that is, , the only phase resetting is determined by . When the perturbation is perpendicular to the LC, it results in that and there is no phase resetting (points “” and “”) at these two neutral points.