Scenarios of pattern formations with decreasing the diffusion indices of the activator. (a): antispiral, α = 2; (b): antispiral, α = 1.8; (c): stable negative hexagonal pattern, α = 1.73; (d): stable stripe, α = 1.7; (e): travelling hexagonal pattern, α = 1.5; (f): travelling wave, α = 1.3. (g): dependance of the amplitude of antispiral (a)–(b) on the time; (h): dependance of the amplitude of patterns (c)–(f) on the time. The oscillation period in panel (g) is 16.72 (16.58) t.u. for α = 1.8 (α = 2). The amplitudes of panels (g) and (h) are measured from the center site of patterns (a)–(f), respectively. Domain sizes are set L × L = 20 × 20 s.u.² in panels (a) and (b), L × L = 0.4 × 0.4 s.u.² in panels (c)–(f), respectively.