Search

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.cogpsych.2010.05.001 Byline: Ansgar D. Endress, Marc D. Hauser Keywords: Word segmentation; Prosody; Language universals; Language acquisition; Statistical learning Abstract: When listening to speech from one's native language, words seem to be well separated from one another, like beads on a string. When listening to a foreign language, in contrast, words seem almost impossible to extract, as if there was only one bead on the same string. This contrast reveals that there are language-specific cues to segmentation. The puzzle, however, is that infants must be endowed with a language-independent mechanism for segmentation, as they ultimately solve the segmentation problem for any native language. Here, we approach the acquisition problem by asking whether there are language-independent cues to segmentation that might be available to even adult learners who have already acquired a native language. We show that adult learners recognize words in connected speech when only prosodic cues to word-boundaries are given from languages unfamiliar to the participants. In both artificial and natural speech, adult English speakers, with no prior exposure to the test languages, readily recognized words in natural languages with critically different prosodic patterns, including French, Turkish and Hungarian. We suggest that, even though languages differ in their sound structures, they carry universal prosodic characteristics. Further, these language-invariant prosodic cues provide a universally accessible mechanism for finding words in connected speech. These cues may enable infants to start acquiring words in any language even before they are fine-tuned to the sound structure of their native language. Author Affiliation: Department of Psychology, Harvard University, Cambridge, MA, USA Article History: Accepted 18 May 2010

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jml.2008.10.003 Byline: Ansgar D. Endress (a), Jacques Mehler (b) Keywords: Statistical learning; Transition probabilities; Word segmentation; Cue integration; Perceptual cues to word learning Abstract: Word-segmentation, that is, the extraction of words from fluent speech, is one of the first problems language learners have to master. It is generally believed that statistical processes, in particular those tracking 'transitional probabilities' (TPs), are important to word-segmentation. However, there is evidence that word forms are stored in memory formats differing from those that can be constructed from TPs, i.e. in terms of the positions of phonemes and syllables within words. In line with this view, we show that TP-based processes leave learners no more familiar with items heard 600 times than with 'phantom-words' not heard at all if the phantom-words have the same statistical structure as the occurring items. Moreover, participants are more familiar with phantom-words than with frequent syllable combinations. In contrast, minimal prosody-like perceptual cues allow learners to recognize actual items. TPs may well signal co-occurring syllables; this, however, does not seem to lead to the extraction of word-like units. We review other, in particular prosodic, cues to word-boundaries which may allow the construction of positional memories while not requiring language-specific knowledge, and suggest that their contributions to word-segmentation need to be reassessed. Author Affiliation: (a) Department of Psychology, Harvard University, William James Hall 984, 33 Kirkland Street, Cambridge, MA 02138, USA (b) International School for Advanced Studies, Trieste, Italy Article History: Received 22 January 2008; Revised 12 October 2008

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2008.08.015 Byline: Elisabetta Versace, Ansgar D. Endress, Marc D. Hauser Abstract: To maximize transmission in noisy environments, vocalizing animals have evolved capacities to avoid the masking effects of biotic and abiotic sound sources, such as changing the structure and timing of acoustic signals. Here we explore this problem from a new angle, asking whether animals can extract predictive acoustic cues from an intermittently noisy environment and use this information to guide the timing of their vocalizations. In a series of experiments, we presented cottontop tamarins, Saguinus oedipus, with loud noise interrupted by speech syllables and silence. The silences were either long enough to accommodate the full length of their species-specific contact calls or too short. The task, in brief, was for tamarins to pick out the acoustic cues predicting long versus short gaps of silence, and to time their vocalizations to follow cues associated with long gaps. Consistently, and across all subjects tested, tamarins were able to extract the acoustic cues predicting the long gaps, using them to call in the long gaps and consequently, avoiding both the energetic and masking costs of calling in noise. We discuss these findings and the potential applications of this technique to broader questions of pattern recognition and the flexible use of vocal signals in a noisy environment. Author Affiliation: (a) Department of Psychology, University of Trieste, Italy (a ) Department of Psychology, Harvard University, U.S.A. (a ) Department of Biological Anthropology, Harvard University, U.S.A. (As.) Department of Organismic and Evolutionary Biology, Harvard University, U.S.A. Article History: Received 30 January 2007; Revised 31 March 2007; Accepted 7 August 2008 Article Note: (miscellaneous) MS. number: A07-00005R

Abstract: While content words (e.g., ‘dog’) tend to carry meaning, function words (e.g., ‘the’) mainly serve syntactic purposes. Here, we ask whether 17-month old infants can use one language–universal cue to identify function word candidates: their high frequency of occurrence. In Experiment 1, infants listened to a series of short, naturally recorded sentences in a foreign language (i.e., in French). In these sentences, two determiners appeared much more frequently than any content word. Following this, infants were presented with a visual object, and simultaneously with a word pair composed of a determiner and a noun. Results showed that infants associated the object more strongly with the infrequent noun than with the frequent determiner. That is, when presented with both the old object and a novel object, infants were more likely to orient towards the old object when hearing a label with a new determiner and the old noun compared to a label with a new noun and the old determiner. In Experiment 2, infants were tested using the same procedure as in Experiment 1, but without the initial exposure to French sentences. Under these conditions, infants did not preferentially associate the object with nouns, suggesting that the preferential association between nouns and objects does not result from specific acoustic or phonological properties. In line with various biases and heuristics involved in acquiring content words, we provide the first direct evidence that infants can use distributional cues, especially the high frequency of occurrence, to identify potential function words. [Copyright &y& Elsevier]

A wide variety of organisms employ specialized mechanisms to cope with the demands of their environment. We suggest that the same is true for humans when acquiring artificial grammars, and at least some basic properties of natural grammars. We show that two basic mechanisms can explain many results in artificial grammar learning experiments, and different linguistic regularities ranging from stress assignment to interfaces between different components of grammar. One mechanism is sensitive to identity relations, whereas the other uses sequence edges as anchor points for extracting positional regularities. This piecemeal approach to mental computations helps to explain otherwise perplexing data, and offers a working hypothesis on how statistical and symbolic accounts of cognitive processes could be bridged. [Copyright &y& Elsevier]