2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/80123The amplitude equation of Gierer-Mainhardt model has been actually derived near the boundary abuot which Turing and Hopf modes exist. In a parameter region where Hopf-Turing mixed mode solution is stable, a chaotic state that generally results from interaction between mixed modes, is observed. This chaotic region follows a strong selection of a spatially periodic order followed by a local, resonant, very large frequency temporal oscillation. A spatio-temporal forcing, responsible for what obseved, has been identified.7 pages and 9 figuresPattern Formation and SolitonsChaotic Dynamicstext