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Human experience of color results from a complex interplay of perceptual and linguistic systems. At the lowest level of perception, the human visual system transforms the visible light portion of the electromagnetic spectrum into a rich, continuous three-dimensional experience of color. Despite our ability to perceptually discriminate millions of different color shades, most languages categorize color into a number of discrete color categories. While the meanings of color words are constrained by perception, perception does not fully define them. Once color words are acquired, they may in turn influence our memory and processing speed for color, although it is unlikely that language influences the lowest levels of color perception. One approach to examining the relationship between perception and language in forming our experience of color is to study children as they acquire color language. Children produce color words in speech for many months before acquiring adult meanings for color words. Research in this area has focused on whether children’s difficulties stem from (a) an inability to identify color properties as a likely candidate for word meanings, or alternatively (b) inductive learning of language-specific color word boundaries. Lending plausibility to the first account, there is evidence that children more readily attend to object traits like shape, rather than color, as likely candidates for word meanings. However, recent evidence has found that children have meanings for some color words before they begin to produce them in speech, indicating that in fact, they may be able to successfully identify color as a candidate for word meaning early in the color word learning process. There is also evidence that prelinguistic infants, like adults, perceive color categorically. While these perceptual categories likely constrain the meanings that children consider, they cannot fully define color word meanings because languages vary in both the number and location of color word boundaries. Recent evidence suggests that the delay in color word acquisition primarily stems from an inductive process of refining these boundaries.

Acoustic theories assume that speech perception begins with an acoustic signal transformed by auditory processing. In classical acoustic theory, this assumption entails perceptual primitives that are akin to those identified in the spectral analyses of speech. The research objective is to link these primitives with phonological units of traditional descriptive linguistics via sound categories and then to understand how these units/categories are bound together in time to recognize words. Achieving this objective is challenging because the signal is replete with variation, making the mapping of signal to sound category nontrivial. Research that grapples with the mapping problem has led to many basic findings about speech perception, including the importance of cue redundancy to category identification and of differential cue weighting to category formation. Research that grapples with the related problem of binding categories into words for speech processing motivates current neuropsychological work on speech perception. The central focus on the mapping problem in classical theory has also led to an alternative type of acoustic theory, namely, exemplar-based theory. According to this type of acoustic theory, variability is critical for processing talker-specific information during speech processing. The problems associated with mapping acoustic cues to sound categories is not addressed because exemplar-based theories assume that perceptual traces of whole words are perceptual primitives. Smaller units of speech sound representation, as well as the phonology as a whole, are emergent from the word-based representations. Yet, like classical acoustic theories, exemplar-based theories assume that production is mediated by a phonology that has no inherent motor information. The presumed disconnect between acoustic and motor information during perceptual processing distinguishes acoustic theories as a class from other theories of speech perception.