Amplitude-modulated spiral waves arising from a secondary Hopf bifurcation in mixed-mode oscillatory media

► Amplitude-modulated spiral waves such as overtargets and superspirals are produced in mixed-mode oscillatory media. ► The secondary Hopf bifurcation could result from coupling between mixed-mode oscillations and diffusion. ► Amplitude-modulated waves can be obtained through adjusting kinetic parameters or the ratio of diffusion coefficients.