Inverse stochastic resonance in electroconvection by multiplicative colored noise.

A kind of inverse stochastic resonance (ISR) observed in ac-driven electroconvection (EC) in a nematic liquid crystal is presented. In successive pattern evolutions by increasing noise intensity V_{N}, a typical EC (with a normalized amplitude A_{0}=1 at V_{N}=0) disappears (A_{0}→0), and then the rest state (A_{0}=0) reenters into the EC (A_{0}=1); eventually, it develops into complicated EC(A_{0}>1). The reversed bell-shaped behavior of A_{0}(V_{N}) is evidence of ISR. The present ISR may be explained by taking into account colored noise characterized by its intensity and correlation time.