3-YEAR-OLDS AND 4-YEAR-OLDS PERCEPTUAL CONFUSIONS FOR SPOKEN WORDS

Although infants have the ability to discriminate a variety of speech contrasts, young children cannot always use this ability in the servic e of spoken-word recognition. The research reported here asked whether the reason young children sometimes fail to discriminate minimal word pairs is that they are less efficient at word recognition than adults , or whether it is that they employ different lexical representations. In particular, the research evaluated the proposal that young childre n's lexical representations are more ''holistic'' than those of adults , and are based on overall acoustic-phonetic properties, as opposed to phonetic segments. Three- and four-year-olds were exposed initially t o an invariant target word and were subsequently asked to determine wh ether a series of auditory stimuli matched or did not match the target . The critical test stimuli were nonwords that varied in their degree of phonetic featural overlap with the target, as well as in terms of t he position(s) within the stimuli at which they differed from the targ et, and whether they differed from the target on one or two segments. Data from four experiments demonstrated that the frequency with which children mistook a nonword stimulus for the target was influenced by e xtent of featural overlap, but not by word position. The data also sho wed that, contrary to the predictions of the holistic hypothesis, stim uli differing from the target by two features on a single segment were confused with the target more often than were stimuli differing by a single feature on each of two segments. This finding suggests that chi ldren use both phonetic features and segments in accessing their menta l lexicons, and that they are therefore much more similar to adults th an is suggested by the holistic hypothesis.