The purpose of the NGA is to find promising subregions of the solution space . Each subregion has a center, which is the sample best solution in that subregion, and a handful of other solutions around the center. In the local phase, COMPASS is initialized with the center solution as the current sample best, and the surrounding solutions as the active solutions defining the most promising area. ...

We examined the influence of context on fine orientation discrimination performance using sinusoidal grating patterns. Discrimination performance was impaired in the presence of modulated surrounds of the same spatial frequency, orientation, and contrast as the center. When center and surround were out-of-phase, separated by a gap of mean luminance, or very different in spatial frequency, perfo...