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Comprehending spoken words requires a lexicon of sound patterns and knowledge of their referents in the world. Tincoff and Jusczyk (1999) demonstrated that 6-month-olds link the sound patterns "Mommy" and "Daddy" to video images of their parents, but not to other adults. This finding suggests that comprehension emerges at this young age and might take the form of very specific word-world links, as in "Mommy" referring only to the infant's mother and "Daddy" referring only to the infant's father. The current study was designed to investigate if 6-month-olds also show evidence of comprehending words that can refer to categories of objects. The results show that 6-month-olds link the sound patterns "hand" and "feet" to videos of an adult's hand and feet. This finding suggests that very early comprehension has a capacity beyond specific, one-to-one, associations. Future research will need to consider how developing categorization abilities, social experiences, and parent word use influence the beginnings of word comprehension.

In 4 studies, 7.5-month-olds used synchronized visua-lauditory correlations to separate a target speech stream when a distractor passage was presented at equal loudness. Infants succeeded in a segmentation task (using the head-turn preference procedure with video familiarization) when a video of the talker's face was synchronized with the target passage (Experiment 1, N=30). Infants did not succeed in this task when an unsynchronized (Experiment 2, N=30) or static (Experiment 3, N=30) face was presented during familiarization. Infants also succeeded when viewing a synchronized oscilloscope pattern (Experiment 4, N=26), suggesting that their ability to use visual information is related to domain-general sensitivities to any synchronized auditory-visual correspondence.

The Possible Word Constraint limits the number of lexical candidates considered in speech recognition by stipulating that input should be parsed into a string of lexically viable chunks. For instance, an isolated single consonant is not a feasible word candidate. Any segmentation containing such a chunk is disfavored. Five experiments using the head-turn preference procedure investigated whether, like adults, 12-month-olds observe this constraint in word recognition. In Experiments 1 and 2, infants were familiarized with target words (e.g., "rush"), then tested on lists of nonsense items containing these words in "possible" (e.g., "niprush" [nip + rush]) or "impossible" positions (e.g., "prush" [p + rush]). The infants listened significantly longer to targets in "possible" versus "impossible" contexts when targets occurred at the end of nonsense items ("rush" in "prush"), but not when they occurred at the beginning ("tan" in "tance"). In Experiments 3 and 4, 12-month-olds were similarly familiarized with target words, but test items were real words in sentential contexts ("win" in "wind" versus "window"). The infants listened significantly longer to words in the "possible" condition regardless of target location. Experiment 5 with targets at the beginning of isolated real words (e.g., "win" in "wind") replicated Experiment 2 in showing no evidence of viability effects in beginning position. Taken together, the findings suggest that, in situations in which 12-month-olds are required to rely on their word segmentation abilities, they give evidence of observing lexical viability constraints in the way that they parse fluent speech.

Investigates whether English learners give evidence of observing markedness and faithfulness constraints relating to nasal place assimilation. Employs the Headturn Preference Procedure to introduce a general experimental paradigm for exploring infants phonological grammars. (Author/VWL)

This study investigated whether 9-month-olds used phonotactic cues to segment words from fluent speech. Results suggested that 9-month-olds use probabilistic phonotactics to segment speech into words, and that high- probability between-word clusters are interpreted as both word onsets and word offsets. (Author/KB)

Explored English-learning infants' capacities to segment bisyllabic words from fluent speech in a series of 15 experiments. Findings suggest that English learners may rely heavily on stress cues when they begin to segment words from fluent speech, but within a few months, infants learn to integrate multiple sources of information about word boundaries. (SLD)

This study compared role of motion in adults' and infants' perception of object unity. Findings favored ecologically-oriented accounts of object perception. Motion was a determinant of object unity for infants. Alignment and common motion contributed to adults' object-unity perception; synchronous color changes did not. Infants detected synchronous changes, but failed to use them as information for object unity. (Author/KB)

Examined speech segmentation in 9-month-old infants, studying phonotactic regularity and prosodic pattern in four experiments involving 96 infants. Discusses implications of the results in light of an integrated multiple-cue approach to speech segmentation in infancy. Contains 92 references. (SLD)

Five experiments examined 15- and 18-month olds' sensitivity to morphosyntactic dependencies. Results indicated that 18-month olds, but not 15-month olds, were sensitive to basic relationship between "is" and "-ing" and that 18-month-olds could track relationships between functor morphemes. Findings were consistent with hypothesis that 18-month olds work with a limited processing window and that they pick up relevant dependencies falling within this window. (Author/KB)

Six experiments involving 192 infants and 1 experiment with 16 college students examined sensitivity to acoustic correlates of phrasal units in English. A basic finding is that nine-month-old infants are sensitive to acoustic markers that correspond to major phrasal units, a sensitivity that develops after six months. (SLD)

Investigates the perceptual representation of speech by young infants using a modification of the high-amplitude sucking (HAS) procedure. Results demonstrate that the infants' representations preserve detailed information about both the consonantal and vocalic portions of the syllables. (Author/RWB)

Two experiments sought to extend the demonstration of English-learning infants' abilities to segment nouns from fluent speech to a new lexical class: verbs. More over, we explored whether two factors previously shown to influence noun segmentation, stress pattern (strong-weak or weak-strong) and type of initial phoneme (consonant or vowel), also influence verb segmentation. Our results establish the early emergence of verb segmentation in English: by 13.5 months for strong-weak consonant- or vowel-initial verbs and for weak-strong consonant-initial verbs; and by 16.5 months for weak-strong verbs beginning with a vowel. This generalizes previous reports of early segmentation to a new lexical class, thereby providing additional evidence that segmentation is likely to contribute to lexical acquisition. The effects of stress pattern and onset type found are similar to those previously obtained for nouns, in that verbs with a weak-strong stress pattern and verbs beginning with a vowel appear to be at a disadvantage in segmentation. Finally, we present prosodic analyses that suggest a possible effect of prosodic boundary and pitch accent distribution on segmentation. These prosodic differences potentially explain a developmental lag in verb segmentation observed in the present study compared to earlier findings for noun segmentation. [ABSTRACT FROM AUTHOR]

Infants' long-term memory for the phonological patterns of words versus the indexical properties of talkers' voices was examined in 3 experiments using the Headturn Preference Procedure (D. G. Kemler Nelson et al., 1995). Infants were familiarized with repetitions of 2 words and tested on the next day for their orientation times to 4 passages-2 of which included the familiarized words. At 7.5 months of age, infants oriented longer to passages containing familiarized words when these were produced by the original talker. At 7.5 and 10.5 months of age, infants did not recognize words in passages produced by a novel female talker, In contrast, 7.5-month-olds demonstrated word recognition in both talker conditions when presented with passages produced by both the original and the novel talker. The findings suggest that talker-specific information can prime infants' memory for words and facilitate word recognition across talkers. [ABSTRACT FROM AUTHOR]

Examines developments in acquiring native language sound organization during infancy. Capacities for discriminating and categorizing speech sounds; Sensitivity to native language; Impact of the changes in speaking rates on the acoustic characteristics of speech sounds.

Examines the word segmentation cue of the eight-months-old infants. Utilization of headturn preference procedure in investigating the integration of multiple cues; Continuous stream of speech based on statistical cues; Preference of subtle speech produced by co-articulation.

Discusses the evolution of infants' language-discrimination abilities. Influence of the rhythm of one's native language on on-line speech processing; Language discrimination abilities of English-learning 5-month-olds babies; Infant's ability to discriminate between rhythmic classes; Infants' reliance on prosodic information to distinguish the native language.

Discusses whether infants are sensitive to syllable weight, a linguistic factor governing the assignment of English lexical stress. Research showing that nine-month-old infants listened longer to words exhibiting Strong-Weak rather than Weak-Strong stress pattern; Evidence that infants prefer both words that begin with a Strong syllable and Strong syllables that are heavy; Suggestion that sensitivity to surface linguistic patterns and the principles that underlie them may be independent in early language acquisition.

Examines the issue of how speech sounds may be treated by infants as special signals relative to other kinds of acoustic stimuli. Consideration of the mechanisms underlying the infant's perception of speech; Processing of speech in the inherent salience which such sounds have for infants; Development of speech perception following the course of a guided learning process.

Studies infants' sensitivity to phrase structure in music using a visual preference procedure. Division of Mozart minuets into segments; Significance of the infants' behavior; Correlations between certain musical variables and the infants' preferences for the musical passages.

Abstract: Infants were familiarized with fluent speech containing target word sequences coincident with or straddling clauses. Infants later preferred new passages containing the target sequences heard as clause-coincident during familiarization and test, suggesting that prosodic cohesiveness influences infants’ encoding and recognition of speech. [Copyright &y& Elsevier]

The current study explores infants’ use of prosodic cues coincident with phrases in processing fluent speech. After familiarization with two versions of the same word sequence, both 6- and 9-month-olds showed a preference for a passage containing the sequence as a noun phrase over a passage with the same sequence as a syntactic non-unit. However, this result was found only in one of the two groups, the group exposed to a stronger prosodic difference between the syntactic and non-syntactic sequences. Six month olds were tested in the same way on passages containing verb phrases. In this case, both groups preferred the passage with the verb phrase to the passage with the same word sequence as a syntactic non-unit. These results provide the first evidence that infants as young as 6 months old are sensitive to prosodic markers of syntactic units smaller than the clause, and, in addition, that they use this sensitivity to recognize phrasal units, both noun and verb phrases, in fluent speech. This ability to use phrase-level prosodic cues is variable, however, and appears to depend on the strength or number of cues associated with these syntactic units. [Copyright &y& Elsevier]