When children learn a new word, such as the name for an object, they must then figure out what other objects should receive this same label. This can be an especially challenging problem for color words because different examples of the same color category can vary widely and the exact boundaries of individual color labels are not obvious. For example, once a child learns that blue can refer to the color of the sky, she must also determine whether blueberries, grapes or grass receive the same label. Although the boundaries for what differentiates blue from purple or green seem straightforward to adults, children experience some ambiguity, and different cultures actually employ different color categories with different boundaries. For example, some cultures refer to blue and green things with the same color label. Thus, to learn color terms, children must figure out where blue begins and ends. The current research investigates how children solve this complex problem by examining color word learning in speakers of English and Otji-Herero. Otji-Herero is spoken by the Himba, an ethnic group in rural Namibia, and contains only 5 color terms to cover the same range of colors that English speakers typically label using 11 terms (red, orange, yellow, green, blue, purple, pink, brown, gray, black and white). The research investigates how differences in exposure to visual colors, combined with differently sized and structured color vocabularies, affect how individuals establish color word categories.
The project will investigate how learners encode color with language in three parts. First, it will test children's early comprehension using infant-friendly eye-tracking methods to determine the initial assumptions that guide first color word meanings in English-learning children (18-30 months). Second, the project will test longitudinal category change. To do so, the researchers will follow children from the time they produce their first color words until they acquire adult-like meanings for all 11 English basic color terms. Finally, these naturalistic studies of category change will be complemented by studies of experimental categorical change in which researchers introduce new color words to individuals who have divided their color space into 5 (Otji-Herero) or 11 (as in English) words while manipulating the type of visual evidence they receive during training. The researchers will also photograph the learning environments of participants to test how visual experience impacts changes in color word meanings. These photographs will be used to create a valuable online database as a resource for other researchers. Using these visual images as well as existing databases on children's linguistic input, the researchers will construct a computational model of how learners use visual and linguistic information to construct color word meanings.
