Fig. 3.

IR light pulses increased the maximum of $dV/dt$ of the ${\mathrm{AP}}_{\mathrm{prop}}$. (a) Phase plot of a pair of ${\mathrm{AP}}_{\mathrm{prop}}$ with (red) and without (blue) IR light. Arrows indicate the maximum of $dV/dt$. Stars indicate the amplitude of the ${\mathrm{AP}}_{\mathrm{prop}}$. (b) The maximum of $dV/dt$ of the ${\mathrm{AP}}_{\mathrm{prop}}$ under IR light illumination ($N=5$) exhibited a significant increase of $7\pm 1.7\%$ ($p=0.0006$) compared to the control values. (c) The maxima of $dV/dt$ of the ${\mathrm{AP}}_{\mathrm{TECC}}$ under control and IR light illumination conditions ($N=6$) did not differ statistically ($p=0.5620$). (d) The maxima of $dV/dt$ of the ${\mathrm{AP}}_{\mathrm{prop}}$ under 13.1-mW IR light illumination ($N=4$) exhibited an increase of $21\%\pm 1.6\%$ ($p=0.0011$) compared to the control values. (e) The maxima of $dV/dt$ of the ${\mathrm{AP}}_{\mathrm{TECC}}$ under control and IR light illumination at 13.1-mW conditions ($N=5$) did not differ statistically ($p=0.0656$).