to the starting direction. Lucy defines this approach as “domain-centered” because researchers select a semantic domain and compare it across linguistic and cultural groups. Space is another semantic domain that has proven fruitful for linguistic relativity studies. Spatial categories vary greatly across languages. Speakers rely on the linguistic conceptualization of space in performing many ordinary tasks. Levinson and others reported three basic spatial categorizations. While many languages use combinations of them, some languages exhibit only one type and related behaviors. For example, Yimithirr only uses absolute directions when describing spatial relations — the position of everything is described by using the cardinal directions. Speakers define a location as "north of the house", while an English speaker may use relative positions, saying "in front of the house" or "to the left of the house". Separate studies by Bowerman and Slobin analyzed the role of language in cognitive processes. Bowerman showed that certain cognitive processes did not use language to any significant extent and therefore could not be subject to linguistic relativity. Slobin described another kind of cognitive process that he named "thinking for speaking" — the kind of process in which perceptional data and other kinds of prelinguistic cognition are translated into linguistic terms for communication. These, Slobin argues, are the kinds of cognitive process that are at the root of linguistic relativity. Colour terminology Since Brown and Lenneberg believed that the objective reality denoted by language was the same for speakers of all languages, they decided to test how different languages codified the same message differently and whether differences in codification could be proven to affect behavior. Brown and Lenneberg designed experiments involving the codification of colors. In their first experiment, they investigated whether it was easier for speakers of English to remember color shades for which they had a specific name than to remember colors that were not as easily definable by words. This allowed them to compare the linguistic categorization directly to a non-linguistic task. In a later experiment, speakers of two languages that categorize colors differently (English and Zuni) were asked to recognize colors. In this way, it could be determined whether the differing color categories of the two speakers would determine their ability to recognize nuances within color categories. Brown and Lenneberg found that Zuni speakers who classify green and blue together as a single color did have trouble recognizing and remembering nuances within the green/blue