Regier and Kay (2009) reported evidence that linguistic categories affect categorical perception primarily in the right-eye visual field. The right-eye visual field is controlled by the left hemisphere of the brain, which also controls language faculties. Davidoff (2001) presented evidence that in color discrimination tasks, native English speakers discriminated more easily between color stimuli across a determined blue-green boundary than within the same side, but did not show categorical perception when given the same task with Berinmo "nol" and "wor"; Berinmo speakers performed oppositely.