When people learn a new color category, they pay special attention to the boundary regions, and performance improves in these regions alone. It is as if learning has the effect of ‘‘warping’’ perceptual space at these locations in order to enable correct categorization. Although the experimental results I have summarized do not necessarily support the strongest form of the linguistic relativity hypothesis (that language determines thought), they do indicate that a somewhat less strong form of the hypothesis may be true: Language may affect perception. When children learn the color terms of their language, they go through a perceptual learning process that is very similar to the one experienced by the participants in our laboratory studies, except it takes place earlier in life and lasts much longer (recall that the degree of brain plasticity is higher in infancy than in adulthood). The resulting change in perceptual space might thus manifest itself in patterns of performance on various laboratory tasks, such as the ones my colleagues and I have used in our investigations.