Figure 1

Top row: Tip trajectories of clockwise rotating spiral waves without electric field. Bottom row: Tip trajectories in the presence of a dc electric field. Left column: Highly excitable medium. Right column: Weakly excitable medium.

Top row: Tip trajectories of clockwise rotating spiral waves without electric field. Bottom row: Tip trajectories in the presence of a dc electric field. Left column: Highly excitable medium. Right column: Weakly excitable medium.