Below is a list of all publications. You can select one or more themes to view the relevant (disjunctive) sublist.
- RGiavazzi, M., R. Daland, S. Palminteri, S. Peperkamp, L. Brugières, C. Jacquemot, C. Schramm, L. Cleret de Langavant & A.-C. Bachoud-Lévi (in press). The causal role of the striatum in linguistic selection: Evidence from Huntington’s disease and computational modeling. Cortex.Though accumulating evidence indicates that the striatum is recruited during language processing, the specific function of this subcortical structure in language remains to be elucidated. To answer this question, we used Huntington's disease as a model of striatal lesion. We investigated the morphological deficit of 30 early Huntington's disease patients with a novel linguistic task that can be modeled within an explicit theory of linguistic computation. Behavioral results reflected an impairment in HD patients on the linguistic task. Computational model-based analysis compared the behavioral data to simulated data from two distinct lesion models, a selection deficit model and a grammatical deficit model. This analysis revealed that the impairment derives from an increased randomness in the process of selecting between grammatical alternatives, rather than from a disruption of grammatical knowledge per se. Voxel-based morphometry permitted to correlate this impairment to dorsal striatal degeneration. We thus show that the striatum holds a role in the selection of linguistic alternatives, just as in the selection of motor and cognitive programs.
- RAFort, M., I. Lammertink, S. Peperkamp, A. Guevara-Rukoz, P. Fikkert & S. Tsuji (2018). SymBouki: a meta-analysis on the emergence of sound symbolism in early language acquisition. Developmental Science, 21, e12659.Adults and toddlers systematically associate pseudowords such as ‘bouba’ and ‘kiki’ with round and spiky shapes respectively, a sound symbolic phenomenon known as the “bouba-kiki effect”. To date, whether this sound symbolic effect is a property of the infant brain present at birth or is a learned aspect of language perception remains unknown. Yet, solving this question is fundamental for our understanding of early language acquisition. Indeed, an early sensitivity to such sound symbolic associations could provide a powerful mechanism for language learning, playing a bootstrapping role in the establishment of novel sound-meaning associations. The aim of the present meta-analysis (SymBouKi) is to provide a quantitative overview of the emergence of the bouba-kiki effect in infancy and early childhood. It allows a high-powered assessment of the true sound symbolic effect size by pooling over the entire set of 11 extant studies (6 published, 5 unpublished), entailing data from 425 participants between 4-38 months of age. The quantitative data provide statistical support for a moderate, but significant sound symbolic effect. Further analysis found a greater sensitivity to sound symbolism for bouba-type pseudowords (i.e., round sound-shape correspondences) than for kiki-type pseudowords (i.e., spiky sound-shape correspondences). For the kiki-type pseudowords, the effect emerged with age. Such discrepancy challenges the view that sensitivity to sound symbolism is an innate language mechanism rooted in an exuberant interconnected brain. We propose alternative hypotheses where both innate and learned mechanisms are at play in the emergence of sensitivity to sound symbolic relationships.
- RASundara, M., C. Ngon, K. Skoruppa, N. Feldman, G. Molino Onario, J. Morgan & S. Peperkamp (2018). Young infants’ discrimination of subtle phonetic contrasts. Cognition, 178, 57-66.It is generally accepted that infants initially discriminate native and non-native contrasts and that perceptual reorganization within the first year of life results in decreased discrimination of non-native contrasts and improved discrimination of native contrasts. However, recent findings from Narayan and colleagues (2010) surprisingly suggested that some acoustically subtle native-language contrasts might not be discriminated until the end of the first year of life. We first provide countervailing evidence that young English-learning infants can discriminate the Filipino contrast tested by Narayan et al., when tested in a more sensitive paradigm. Next, we show that young infants learning either English or French can also discriminate comparably subtle non-native contrasts from Tamil. These findings show that Narayan et al.’s null findings were due to methodological choices and indicate that young infants are sensitive to even subtle acoustic contrasts that cue phonetic distinctions cross-linguistically. Based on experimental results and acoustic analyses we argue that instead of specific acoustic metrics, infant discrimination results themselves are the most informative about the salience of phonetic distinctions.
- RCTurnbull, R. & S. Peperkamp (2017). The asymmetric contribution of consonants and vowels to phonological similarity: Evidence from lexical priming. The Mental Lexicon 12, 404-430.Lexical priming is known to arise from phonological similarity between prime and target, and this phenomenon is an important component of our understanding of the processes of lexical access and competition. However, the precise nature of the role of phonological similarity in lexical priming is understudied. In the present study, two experiments were conducted in which participants performed auditory lexical decision on CVC targets which were preceded by primes that either matched the target in all phonemes (CVC condition), in the first two phonemes (CV_ condition), the last two phonemes (_VC condition), the initial and last phonemes (C_C condition) or no phonemes (unrelated condition). Relative to the unrelated condition, all conditions except CV_ led to facilitation of response time to target words. The _VC and C_C conditions led to equivalent facilitation magnitude, while the CV_ condition showed neither facilitation nor inhibition. Accounting for these results requires appeal to processes of lexical competition and also to the notion that phonemes do not lend equivalent phonological similarity; that is, vowels and consonants are processed differently.
- RCGuevara-Rukoz, A., I. Lin, M. Morii, Y. Minagawa. E. Dupoux & S. Peperkamp (2017). Which epenthetic vowel? Phonetic categories versus acoustic detail in perceptual vowel epenthesis. Journal of the Acoustical Society of America, 142, EL211-EL217.This study aims to quantify the relative contributions of phonetic categories and acoustic detail on phonotactically induced perceptual vowel epenthesis in Japanese listeners. A vowel identification task tested whether a vowel was perceived within illegal consonant clusters and, if so, which vowel was heard. Cross-spliced stimuli were used in which vowel coarticulation present in the cluster did not match the quality of the flanking vowel. Two clusters were used, /hp/ and /kp/, the former containing larger amounts of resonances of the preceding vowel. While both flanking vowel and coarticulation influenced vowel quality, the influence of coarticulation was larger, especially for /hp/.
- RBCLev-Ari, S., van Heugten, M. & Peperkamp, S. (2017). Relative difficulty of understanding foreign accents as a marker of proficiency. Cognitive Science, 41, 1106-1118.Foreign-accented speech is generally harder to understand than native-accented speech. This difficulty is reduced for non-native listeners who share their first language with the non-native speaker. It is currently unclear, however, how non-native listeners deal with foreign-accented speech produced by speakers of a different language. We show that the process of (second) language acquisition is associated with an increase in the relative difficulty of processing foreign-accented speech. Therefore, experiencing greater relative difficulty with foreign-accented speech compared with native speech is a marker of language proficiency. These results contribute to our understanding of how phonological categories are acquired during second language learning.
- RCLev-Ari, S. & Peperkamp, S. (2017). Language for $200: Success in the environment influences grammatical alignment. Journal of Language Evolution, 2, 177-187.Speakers constantly learn language from the environment by sampling their linguistic input and adjusting their representations accordingly. Logically, people should attend more to the environment and adjust their behavior in accordance with it more the lower their success in the environment is. We test whether the learning of linguistic input follows this general principle in two studies: a corpus analysis of a TV game show, Jeopardy, and a lab task modeled after Go Fish. We show that lower (non-linguistic) success in the task modulates learning of and reliance on linguistic patterns in the environment. In Study 1 we find that poorer performance increases conformity with linguistic norms, as reflected by increased preference for frequent grammatical structures. In Study 2, which consists of a more interactive setting, poorer performance increases learning from the immediate social environment, as reflected by greater repetition of others' grammatical structures. We propose that these results have implications for models of language production and language learning and for the propagation of language change. In particular, they suggest that linguistic changes might spread more quickly in times of crisis, or when the gap between more and less successful people is larger. The results might also suggest that innovations stem from successful individuals while their propagation would depend on relatively less successful individuals. We provide a few historical examples that are in line with the first suggested implication, namely, that the spread of linguistic changes is accelerated during difficult times, such as war time and an economic downturn.
- RAFort, M., P. Brusini, J. Carbajal, Sun & S. Peperkamp (2017). A novel form of perceptual attunement: context-dependent perception of a native contrast in 14-month-old infants. Developmental Cognitive Neuroscience, 26, 45-51.By the end of their first year of life, infants have become experts in discriminating the sounds of their native language, while they have lost the ability to discriminate non-native contrasts. This type of phonetic learning is referred to as perceptual attunement. In the present study, we investigated the emergence of a context-dependent form of perceptual attunement in infancy. Indeed, some native contrasts are not discriminated in certain phonological contexts by adults, due to the presence of a language-specific process that neutralizes the contrasts in those contexts. We used a mismatch design and recorded high-density Electroencephalography (EEG) in French-learning 14-month-olds. Our results show that similarly to French adults, infants fail to discriminate a native voicing contrast (e.g., [f] vs. [v]) when it occurs in a specific phonological context (e.g., [ofbe] vs. [ovbe], no mismatch response), while they successfully detected it in other phonological contexts (e.g., [ofne] vs. [ovne], mismatch response). The present results demonstrate for the first time that by the age of 14 months, infants' phonetic learning does not only rely on the processing of individual sounds, but also takes into account in a language-specific manner the phonological contexts in which these sounds occur.
- RCMartin, A. (Alexander) & Peperkamp, S. (2017). Assessing the distinctiveness of phonological features in word recognition: prelexical and lexical influences. Journal of Phonetics, 62, 1-11.Phonological features have been shown to differ from one another in their perceptual weight during word recognition. Here, we examine two possible sources of these asymmetries: bottom-up acoustic perception (some featural contrasts are acoustically more different than others), and top-down lexical knowledge (some contrasts are used more to distinguish words in the lexicon). We focus on French nouns, in which voicing mispronunciations are perceived as closer to canonical pronunciations than both place and manner mispronunciations, indicating that voicing is less important than place and manner for distinguishing words from one another. We find that this result can be accounted for by coalescing the two sources of bias. First, using a prelexical discrimination paradigm, we show that manner contrasts have the highest baseline perceptual salience, while there is no difference between place and voicing. Second, using a novel method to compute the functional load of phonological features, we show that the place feature is most often recruited to distinguish nouns in the French lexicon, while voicing and manner are exploited equally often.
- CLev-Ari, S. & Peperkamp, S. (2016). How the demographic make-up of our community influences speech perception. Journal of the Acoustical Society of America, 139, 3076-3087.Speech perception is known to be influenced by listeners' expectations of the speaker. This paper tests whether the demographic make-up of individuals' communities can influence their perception of foreign sounds by influencing their expectations of the language. Using online experiments with participants from all across the US and matched census data on the proportion of Spanish and other foreign language speakers in participants' communities, this paper shows that the demographic make-up of individuals' communities influences their expectations of foreign languages to have an alveolar trill versus a tap (Exp. 1), as well as their consequent perception of these sounds (Exp. 2). Thus, the paper shows that while individuals' expectations of foreign language to have a trill occasionally lead them to misperceive a tap in a foreign language as a trill, a higher proportion of non-trill language speakers in one's community decreases this likelihood. These results show that individuals' environment can influence their perception by shaping their linguistic expectations.
- ANgon, C. & Peperkamp, S. (2016). What infants know about the unsaid: Phonological categorization in the absence of auditory input. Cognition, 152, 53-60.Acquiring a lexicon constitutes an essential step in early language development. From an early age on, infants store words with well-specified phonological representations, and they can spontaneously activate these representations on the basis of visual information only (Mani & Plunkett, 2010a, 2011). To what extent can infants inspect and categorize phonological representations in the absence of auditory input? The present study focuses on words that infants comprehend but do not attempt to pronounce yet, and introduces a novel methodology based on anticipatory eye-movements. In two experiments, 21-month-old French-learning infants were silently presented with images of familiar objects whose labels they comprehended but did not pronounce yet. We tested whether they could activate the phonological representation of these labels and categorize them based on their length. Infants' performance exceeded chance when the target words were mono- and trisyllabic, but not when they were mono- and disyllabic. Thus, even in the absence of auditory input infants can activate the phonological representation of words they do not pronounce yet, and use this representation to perform a categorization based on word length, provided the length difference is substantial.
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- CSun, Y. & Peperkamp, S. (2016). The role of speech production in phonological decoding during visual word recognition: evidence from phonotactic repair. Language, Cognition & Neuroscience, 31, 391-403.During visual word recognition, readers rely not only on a word's orthography, but also on the phonological code that is generated from print. Previous research showed that the phonological decoding of non-native letter sequences is influenced by phonotactic constraints of the reader's native language (Hallé et al., 2008). In the current study, we investigate the mechanisms underlying such phonotactic repair during visual word recognition. We focus on a phonotactic constraint in French, according to which words cannot begin with /tl/. Native speakers of French are known to perceive word-initial /tl/ as /kl/. Using a visual priming paradigm, we show that the same phonotactic repair also occurs when the cluster 'tl' is presented visually, but, crucially, only when participants' speech production system is available; under articulatory suppression the repair fails to occur. Together, these results show that the speech production system is actively involved in phonological decoding during reading.
- CSun, Y., Giavazzi, M., Adda-Decker, M., Barbosa, L., Kouider, S., Bachoud-Lévi, A.-C., Jacquemot, C., & Peperkamp, S. (2015). Complex linguistic rules modulate early auditory brain responses. Brain and Language, 149, 55-65.During speech perception, listeners compensate for phonological rules of their language. For instance, English place assimilation causes "green boat" to be typically pronounced as "greem boat"; English listeners, however, perceptually compensate for this rule and retrieve the intended sound (n). Previous research using EEG has focused on rules with clear phonetic underpinnings, showing that perceptual compensation occurs at an early stage of speech perception. We tested whether this early mechanism also accounts for the compensation for more complex rules. We examined compensation for French voicing assimilation, a rule with abstract phonological restrictions on the contexts in which it applies. Our results reveal that perceptual compensation for this rule by French listeners modulates an early ERP component. This is evidence that early stages of speech sound categorization are sensitive to complex phonological rules of the native language.
- CMartin, A. (Alexander) & Peperkamp, S. (2015). Asymmetries in the exploitation of phonetic features for word recognition. Journal of the Acoustical Society of America, 137, EL307-EL313.French listeners' reliance on voicing, manner, and place was tested in a mispronunciation detection task. Mispronounced words were more likely to be recognized when the mispronunciation concerned voicing rather than manner or place. This indicates that listeners rely less on the former than on the latter for the purposes of word recognition. Further, the role of visual cues to phonetic features was explored by the task being conducted in both an audio-only and an audiovisual version, but no effect of modality was found. Discussion focuses on cross-linguistic comparisons and lexical factors that might influence the weight of individual features.
- CFort, M, Martin, A. (Alexander) & Peperkamp, S. (2015). Consonants are more important than vowels in the bouba-kiki effect. Language and Speech, 58, 247-266.Adult listeners systematically associate certain speech sounds with round or spiky shapes, a sound-symbolic phenomenon known as the "bouba-kiki effect". In this study, we investigate the respective influences of consonants and vowels in this phenomenon. French participants were asked to match auditorily presented pseudowords with one of two visually presented shapes, one round and one spiky. The pseudowords were created by crossing either two consonant pairs with a wide range of vowels (Experiment 1 and 2) or two vowel pairs with a wide range of consonants (Experiment 3). Analyses showed that consonants have a greater influence than vowels in the bouba-kiki effect. This asymmetry cannot be due to an onset bias, as a strong consonantal influence is found both with CVCV (Experiment 1) and VCV (Experiment 2) stimuli. We discuss these results in terms of the differential role of consonants and vowels in speech perception.
- ELev-Ari, S., San Giacomo, M., & Peperkamp, S. (2014). The effect of domain prestige and interlocutors' bilingualism on loanword adaptations. Journal of Sociolinguistics, 18, 658-684.There is great variability in whether foreign sounds in loanwords are adapted, such that segments show cross-word and cross-situational variation in adaptation. Previous research proposed that word frequency, speakers' level of bilingualism and neighborhoods' level of bilingualism can explain such variability. We test for the effect of these factors and propose two additional factors: interlocutors' level of bilingualism and the prestige of the donor language in the loanword's domain. Analyzing elicited productions of loanwords from Spanish into Mexicano in a village where Spanish and Mexicano enjoy prestige in complementary domains, we show that interlocutors' bilingualism and prestige influence the rate of sound adaptation. Additionally, we find that speakers accommodate to their interlocutors, regardless of the interlocutors' level of bilingualism. As retention of foreign sounds can lead to sound change, these results show that social factors can influence changes in a language's sound system.
- CLev-Ari, S. & Peperkamp, S. (2014). The influence of inhibitory skill on phonological representations in production and perception. Journal of Phonetics, 47, 36-46.Inhibition is known to play a role in speech perception and has been hypothesized to likewise influence speech production. In this paper we test whether individual differences in inhibitory skill can lead to individual differences in phonological representations in perception and production. We further examine whether the type of inhibition that influences phonological representation is domain-specific or domain-general. Native French speakers read aloud sentences with words containing a voiced stop that either have a voicing neighbor (target) or not (control). The duration of pre-voicing was measured. Participants similarly performed a lexical decision task on versions of these target and matched control words whose pre-voicing duration was manipulated. Lastly, participants performed linguistic and non-linguistic inhibition tasks. Results indicate that the lower speakers' linguistic or non-linguistic inhibition is, the easier it is for them to recognize words with a voiceless neighbor when these words have a shorter, intermediate, pre-voicing rather than a longer one. Inhibitory skill did not predict recognition time for control words, indicating that the effect was due to the greater activation of the voiceless neighbor. Inhibition did not predict pre-voicing duration in production. These results indicate that individual differences in cognitive skills can influence phonological representations in speech perception.
- ELev-Ari, S. & Peperkamp, S. (2014). An experimental study of the role of social factors in language change. Laboratory Phonology, 5, 379-401.There is great variation in whether foreign sounds in loanwords are adapted or retained. Importantly, the retention of foreign sounds can lead to a sound change in the language. We propose that social factors influence the likelihood of loanword sound adaptation, and use this case to introduce a novel experimental paradigm for studying language change that captures the role of social factors. Specifically, we show that the relative prestige of the donor language in the loanword's semantic domain influences the rate of sound adaptation. We further show that speakers adapt to the performance of their "community", and that this adaptation leads to the creation of a norm. The results of this study are thus the first to show an effect of social factors on loanword sound adaptation in an experimental setting. Moreover, they open up a new domain of experimentally studying language change in a manner that integrates social factors.
- BCCristia, A., Mielke, J., Daland, R. & Peperkamp, S. (2013). Similarity in the generalization of implicitly learned sound patterns. Laboratory Phonology, 4, 259-285.It is likely that generalization of implicitly learned sound patterns to novel words and sounds is structured by a similarity metric, but how may this metric best be captured? We report on an experiment where participants were exposed to an artificial phonology, and frequency ratings were used to probe implicit abstraction of onset statistics. Non-words bearing an onset that was presented during initial exposure were subsequently rated most frequent, indicating that participants generalized onset statistics to new non-words. Participants also rated non-words with untrained onsets as somewhat frequent, indicating generalization to onsets that had not been used during the exposure phase. While generalization could be accounted for in terms of featural distance, it was insensitive to natural class structure. Generalization to untrained sounds was predicted better by models requiring prior linguistic knowledge (either traditional distinctive features or articulatory phonetic information) than by a model based on a linguistically naïve measure of acoustic similarity.
- ASkoruppa, K., Mani, N., Plunkett, K., Cabrol, D. & Peperkamp, S. (2013). Early word recognition in sentence context: French and English 2-year-olds' sensitivity to sentence-medial mispronunciations and assimilations. Infancy, 18, 1007-1029.Recent work has shown that young children can use fine phonetic detail during the recognition of isolated and sentence-final words from early in lexical development. The present study investigates 24-month-olds' word recognition in sentence-medial position in two experiments using an Intermodal Preferential Looking paradigm. In Experiment 1, French toddlers detect word-final voicing mispronunciations (e.g. buz [byz] for bus [bys] 'bus') and they compensate for native voicing assimilations (e.g. buz devant toi 'bus in front of you') in the middle of sentences. Similarly, English toddlers detect word-final voicing mispronunciations (e.g. sheeb for sheep) in Experiment 2, but they do not compensate for illicit voicing assimilations (e.g. sheeb there). Thus, French and English 24-month-olds can take into account fine phonetic detail even if words are presented in the middle of sentences, and French toddlers show language-specific compensation abilities for pronunciation variation caused by native voicing assimilation.
- DLev-Ari, S. & Peperkamp, S. (2013). Low inhibitory skill leads to non-native perception and production in bilinguals' native language. Journal of Phonetics, 41, 320-331.Learning a second language influences speakers' first language, but there is great variability in the degree of influence that speakers exhibit. We show that some of this variability is due to individual differences in inhibitory skill. Particularly, we propose that poorer inhibitory skill leads to greater activation of competing items from the language not in use, and that this greater co-activation ultimately leads to greater influence of the co-activated items on one another. Specifically, we show that bilinguals with lower inhibitory skill exhibit greater influence of the second language on the first. Late English-French bilinguals residing in France produced and perceived Voice Onset Time of voiceless stops in English in a more French-like manner, the lower their inhibitory skill was. We discuss the implications of these results for the role of inhibitory skill in shaping representation in bilingual as well as monolingual language processing.
- AMartin, A. (Andrew), Peperkamp, S. & Dupoux, E. (2013). Learning phonemes with a proto-lexicon. Cognitive Science, 37, 103-124.Before the end of the first year of life, infants begin to lose the ability to perceive distinctions between sounds that are not phonemic in their native language. It is typically assumed that this developmental change reflects the construction of language-specific phoneme categories, but how these categories are learned largely remains a mystery. Peperkamp, Le Calvez, Nadal, & Dupoux (2006) present an algorithm that can discover phonemes using the distributions of allophones as well as the phonetic properties of the allophones and their contexts. We show that a third type of information source, the occurrence of pairs of minimally-differing word forms in speech heard by the infant, is also useful for learning phonemic categories, and is in fact more reliable than purely distributional information in data containing a large number of allophones. In our model, learners build an approximation of the lexicon consisting of the high-frequency n-grams present in their speech input, allowing them to take advantage of top-down lexical information without needing to learn words. This may explain how infants have already begun to exhibit sensitivity to phonemic categories before they have a large receptive lexicon.
- ASkoruppa, K., Pons, F., Bosch, L., Christophe, A., Cabrol, D. & Peperkamp, S. (2013). The development of word stress perception in French and Spanish infants. Language Learning and Development 9, 88-104.This study focuses on the development of lexical stress perception during the first year of life. Previous research shows that cross-linguistic differences in word stress organisation translate into differences in word stress processing from a very early age: At 9 months, Spanish-learning infants, learning a language with variable word stress, can distinguish segmentally varied stress-initial (e.g. níla, túli) and stress-final (e.g. lutá, pukí) nonsense words in a headturn preference procedure. However, French infants, who learn a language with fixed word stress, can only distinguish between initial and final stress when no segmental variability is involved (Skoruppa et al., 2009). The present study investigates the emergence of this cross-linguistic difference. We show that neither Spanish nor French 6-month-olds encode stress patterns in the presence of segmental variability (Exp. 1), while both groups succeed in the absence of segmental variability (Exp. 2). Hence, only Spanish infants, who learn a variable stress language, get better at tracking stress patterns in segmentally varied words between the ages of 6 and 9 months. In contrast, all infants seem to be able to discriminate basic stress patterns in the absence of segmental variability during the first nine months of life, regardless of the status of stress in their native language.
- ASkoruppa, K., Mani, N. & Peperkamp, S. (2013). Toddlers' processing of phonological alternations: Early compensation for assimilation in English and French. Child Development, 84, 313-330.Using a picture pointing task, this study examines toddlers' processing of phonological alternations that trigger sound changes in connected speech. Three experiments investigate whether 2;5- to 3-year-old children take into account assimilations - processes by which phonological features of one sound spread to adjacent sounds - for the purpose of word recognition (e.g., in English, ten pounds can be produced as tem pounds). English toddlers show sensitivity to native place assimilations during lexical access in Experiment 1. Likewise, French toddlers compensate for French voicing assimilations in Experiment 2. However, French toddlers do not take into account a hypothetical non-native place assimilation rule in Experiment 3, suggesting that compensation for assimilation is already language-specific.
- ANgon, C., Martin, A. (Andrew), Dupoux, E., Cabrol, D., Dutat, M. & Peperkamp, S. (2013). (Non)words, (non)words, (non)words: evidence for a proto-lexicon during the first year of life. Developmental Science, 16, 24-34.Previous research with artificial language learning paradigms has shown that infants are sensitive to statistical cues to word boundaries (Saffran, Aslin & Newport, 1996) and that they can use these cues to extract word-like units (Saffran, 2001). However, it is unknown whether infants use statistical information to construct a receptive lexicon when acquiring their native language. In order to investigate this issue, we rely on the fact that besides real words a statistical algorithm extracts sound sequences that are highly frequent in infant-directed speech but constitute nonwords. In three experiments, we use a preferential listening paradigm to test French-learning 11-month-old infants' recognition of highly frequent disyllabic sequences from their native language. In Experiments 1 and 2, we use nonword stimuli and find that infants listen longer to high-frequency than to low-frequency sequences. In Experiment 3, we compare high-frequency nonwords to real words in the same frequency range, and find that infants show no preference. Thus, at 11 months, French-learning infants recognize highly frequent sound sequences from their native language and fail to differentiate between words and nonwords among these sequences. These results are evidence that they have used statistical information to extract word candidates from their input and stored them in a "protolexicon", containing both words and nonwords.
- ASkoruppa, K., Cristia, A., Peperkamp, S. & Seidl, A. (2011). English-learning infants' perception of word stress patterns. Journal of the Acoustical Society of America, 130, EL50-EL55.Adult speakers of different free stress languages (e.g., English, Spanish) differ both in their sensitivity to lexical stress, and in their processing of suprasegmental and vowel quality cues to stress. In a headturn preference experiment with a familiarization phase, both 8-month-old and 12-month-old English-learning infants discriminated between initial stress and final stress among lists of Spanish-spoken disyllabic non-words that were segmentally varied (e.g. ['nila, 'tuli] vs. [lu'ta, pu'ki]). This is evidence that English-learning infants are sensitive to lexical stress patterns, instantiated primarily by suprasegmental cues, during the second half of the first year of life.
- CDupoux, E., Parlato, E., Frota, S., Hirose, Y., Peperkamp, S. (2011). Where do illusory vowels come from? Journal of Memory and Language, 64, 199-210.Listeners of various languages tend to perceive an illusory vowel inside consonant clusters that are illegal in their native language. Here, we test whether this phenomenon arises after phoneme categorization or rather interacts with it. We assess the perception of illegal consonant clusters in native speakers of Japanese, Brazilian Portuguese, and European Portuguese, three languages that have similar phonological properties, but that differ with respect to both segmental categories and segmental transition probabilities. We manipulate the coarticulatory information present in the consonant clusters, and use a forced choice vowel labeling task (Experiment 1) and an ABX discrimination task (Experiment 2). We find that only Japanese and Brazilian Portuguese listeners show a perceptual epenthesis effect, and, furthermore, that within these participant groups the nature of the perceived epenthetic vowel varies according to the coarticulation cues. These results are consistent with models that integrate phonotactic probabilities within perceptual categorization, and are problematic for two-step models in which the repair of illegal sequences follows that of categorization.
- BCSkoruppa, K. & Peperkamp, S. (2011). Adaptation to novel accents: Feature-based learning of context-sensitive phonological regularities. Cognitive Science, 35, 348-366.This paper examines whether adults can adapt to novel accents of their native language that contain unfamiliar context-dependent phonological alternations. In two experiments, French participants listen to short stories read in accented speech. Their knowledge of the accents is then tested in a forced-choice identification task. In Experiment 1, two groups of listeners are exposed to newly created French accents in which certain vowels harmonize or disharmonize, respectively, to the rounding of the preceding vowel. Despite the cross-linguistic predominance of vowel harmony over disharmony, the two groups adapt equally well to both accents, suggesting that this typological difference is not reflected in perceptual learning. Experiment 2 further explores the mechanism underlying this type of phonological learning. Participants are exposed to an accent in which some vowels harmonize and others disharmonize, yielding an increased featural complexity. They adapt less well to this regularity, showing that adaptation to novel accents involves feature-based inferences.
- CPeperkamp, S., Vendelin, I. & Dupoux, E. (2010). Perception of predictable stress: A cross-linguistic investigation. Journal of Phonetics, 38, 422-430.Previous studies have documented that speakers of French, a language with predictable stress, have difficulty distinguishing nonsense words that vary in stress position solely (stress "deafness"). In a sequence recall task with adult speakers of five languages with predictable stress (Standard French, Southeastern French, Finnish, Hungarian and Polish) and one language with non-predictable stress (Spanish), it was found that speakers of all languages with predictable stress except Polish exhibited a strong stress "deafness", while Spanish speakers exhibited no such "deafness". Polish speakers yielded an intermediate pattern of results: they exhibited a weak stress "deafness". These findings are discussed in light of current theoretical models of speech perception.
- BDDupoux, E., Peperkamp, S. & Sebastián-Gallés, N. (2010). Limits on bilingualism revisited: stress 'deafness' in simultaneous French-Spanish bilinguals. Cognition, 114, 266-275.We probed simultaneous French-Spanish bilinguals for the perception of Spanish lexical stress using three tasks, two short-term memory encoding tasks and a speeded lexical decision. In all three tasks, the performance of the group of simultaneous bilinguals was intermediate between that of native speakers of Spanish on the one hand and French late learners of Spanish on the other hand. Using a composite stress 'deafness' index measure computed over the results of the three tasks, we found that the performance of the simultaneous bilinguals is best fitted by a bimodal distribution that corresponds to a mixture of the performance distributions of the two control groups. Correlation analyses showed that the variables explaining language dominance are linked to early language exposure. These findings are discussed in light of theories of language processing in bilinguals.
- ASkoruppa, K., Pons, F., Christophe, A., Bosch, L., Dupoux, E., Sebastián-Gallés, N., Alves Limissuri, R. & Peperkamp, S. (2009). Language-specific stress perception by 9-month-old French and Spanish infants. Developmental Science, 12, 914-919.During the first year of life, infants begin to have difficulties perceiving non-native vowel and consonant contrasts, thus adapting their perception to the phonetic categories of the target language. In this paper, we examine the perception of a non-segmental feature, i.e. stress. Previous research with adults has shown that speakers of French (a language with fixed stress) have great difficulties in perceiving stress contrasts (Dupoux, Pallier, Sebastián & Mehler, 1997), whereas speakers of Spanish (a language with lexically contrastive stress) perceive these contrasts as accurately as segmental contrasts. We show that language-specific differences in the perception of stress likewise arise during the first year of life. Specifically, 9-month-old Spanish infants successfully distinguish between stress-initial and stress-final pseudo-words, while French infants of this age show no sign of discrimination. In a second experiment using multiple tokens of a single pseudo-word, French infants of the same age successfully discriminate between the two stress patterns, showing that they are able to perceive the acoustic correlates of stress. Their failure to discriminate stress patterns in the first experiment thus reflects an inability to process stress at an abstract, phonological level.
- CDEPeperkamp, S., Vendelin, I. & Nakamura, K. (2008). On the perceptual origin of loanword adaptations: experimental evidence from Japanese. Phonology, 25, 129-164.Japanese shows an asymmetry in the treatment of word-final [n] in loanwords from English and French: while it is adapted as a moraic nasal consonant in loanwords from English, it is adapted with a following epenthetic vowel in loanwords from French. We provide experimental evidence that this asymmetry originates in the way Japanese speakers perceive word-final [n] in English and French. In Experiment 1 we use a forced choice identification task and show that Japanese speakers identify French [n]-final stimuli as ending in a vowel significantly more often than English ones; the identification of this vowel is shown to correlate with the spectral energy contained in the release of the nasal consonant in the stimuli. In Experiment 2 we use an ABX discrimination task and show that Japanese speakers have difficulties distinguishing French forms ending in [n] from corresponding ones ending in [nu]. Given the primacy of perception over production, we conclude that the Japanese loanword adaptations originate in perception and consist of phonetically minimal transformations. We discuss consequences of our findings for models of loanword adaptation.
- AWhite, K., Peperkamp, S., Kirk, C. & Morgan, J. (2008). Rapid acquisition of phonological alternations by infants. Cognition, 107, 238-265.We explore whether infants can learn novel phonological alternations on the basis of distributional information. In Experiment 1, two groups of 12-month-old infants were familiarized with artificial languages whose distributional properties exhibited either stop or fricative voicing alternations. At test, infants in the two exposure groups had different preferences for novel sequences involving voiced and voiceless stops and fricatives, suggesting that each group had internalized a different familiarization alternation. In Experiment 2, 8.5-month-olds exhibited the same patterns of preference. In Experiments 3 and 4, we investigated whether infants' preferences were driven solely by preferences for sequences of high transitional probability. Although 8.5-month-olds in Experiment 3 were sensitive to the relative probabilities of sequences in the familiarization stimuli, only 12-month-olds in Experiment 4 showed evidence of having grouped alternating segments into a single functional category. Taken together, these results suggest a developmental trajectory for the acquisition of phonological alternations using distributional cues in the input.
- BDDupoux, E., Sebastián-Gallés, N., Navarrete, E. & Peperkamp, S. (2008). Persistent stress 'deafness': the case of French learners of Spanish. Cognition, 106, 682-706.Previous research by Dupoux et al. found that French speakers, as opposed to Spanish ones, are impaired in discrimination tasks with stimuli that vary only in the position of stress. However, what was called stress 'deafness' was only found in tasks that used high phonetic variability and memory load, not in cognitively less demanding tasks such as single token AX discrimination. This raised the possibility that instead of a perceptual problem, monolingual French speakers might simply lack a metalinguistic representation of contrastive stress, which would impair them in memory tasks. We examined a sample of 39 native speakers of French who underwent formal teaching of Spanish after age 10, and varied in degree of practice in this language. Using a sequence recall task, we observed in all our groups of late learners of Spanish the same impairment in short-term memory encoding of stress contrasts that was previously found in French monolinguals. Furthermore, using a speeded lexical decision task with word-nonword minimal pairs that differ only in the position of stress, we found that all late learners had much difficulty in the use of stress to access the lexicon. Our results show that stress 'deafness' is better interpreted as a lasting processing problem resulting from the impossibility for French speakers to encode contrastive stress in their phonological representations. This affects their memory encoding as well as their lexical access in on-line tasks. The generality of such a persistent suprasegmental 'deafness' is discussed in relation to current findings and models on the perception of non-native phonological contrasts.
- CPeperkamp, S. (2007). Do we have innate knowledge about phonological markedness? Comments on Berent, Steriade, Lennertz, and Vaknin. Cognition, 104, 631-637.In their article 'What we know about what we have never heard: Evidence from perceptual illusions', Berent, Steriade, Lennertz, and Vaknin (2007) argue that English listeners' perception of onset clusters is reflected by the markedness of these clusters. Specifically, they show that the more an onset cluster is marked, the more likely it is perceived with an illusory epenthetic vowel by English listeners. English words do not contain any of the onset cluster types used in the experiments; hence markedness effects cannot be the result of phonological learning. I argue that their conclusion is not justified for two reasons. First, all experiments test whether different types of clusters are perceived with an epenthetic schwa or not. Epenthesis, however, is not the only possible perceptual repair. Hence, we cannot rule out that those cluster types that tend not to undergo perceptual epenthesis are more often subject to some other perceptual repair, thus undermining the inference that they are perceived more faithfully. Second, although the authors do consider a phonetic explanation of the results, their arguments against such an explanation are inconclusive.
- APeperkamp, S., Le Calvez, R., Nadal, J.-P. & Dupoux, E. (2006). The acquisition of allophonic rules: statistical learning with linguistic constraints. Cognition, 101, B31-B41.Phonological rules relate surface phonetic word forms to abstract underlying forms that are stored in the lexicon. Infants must thus acquire these rules in order to infer the abstract representation of words. We implement a statistical learning algorithm for the acquisition of one type of rule, namely allophony, which introduces context-sensitive phonetic variants of phonemes. This algorithm is based on the observation that different realizations of a single phoneme typically do not appear in the same contexts (ideally, they have complementary distributions). In particular, it measures the discrepancies in context probabilities for each pair of phonetic segments. In Experiment 1, we test the algorithm's performances on a pseudo-language and show that it is robust to statistical noise due to sampling and coding errors, and to non-systematic rule application. In Experiment 2, we show that a natural corpus of semiphonetically transcribed child-directed speech in French presents a very large number of near-complementary distributions that do not correspond to existing allophonic rules. These spurious allophonic rules can be eliminated by a linguistically motivated filtering mechanism based on a phonetic representation of segments. We discuss the role of a priori linguistic knowledge in the statistical learning of phonology.
- DEVendelin, I. & Peperkamp, S. (2006). The influence of orthography on loanword adaptations. Lingua, 116, 996-1007.We investigate the influence of orthography on loanword adaptations by means of an experiment in which late French-English bilinguals produce on-line adaptations of English non-words. In half of the experiment, the stimuli are presented orally only, whereas in the other half, the oral stimuli are accompanied by their written representation. The adaptations of eight English vowels are shown to be different according to whether the input is oral or mixed (i.e. oral + written). In particular, the adaptations based on the mixed input more often reflect the way French speakers are used to read English graphemes. These results thus confirm the sensitivity of loanword adaptations to the presence versus absence of a written representation. We conclude that in order to control for orthography, loanword adaptations are best studied in an experimental framework.
- CChristophe, A., Peperkamp, S., Pallier, C., Block, E. & Mehler, J. (2004). Phonological phrase boundaries constrain lexical access: I. Adult data. Journal of Memory and Language, 51, 523-547.We tested the effect of local lexical ambiguities while manipulating the type of prosodic boundary at which the ambiguity occurred, using French sentences and participants. We observed delayed lexical access when a local lexical ambiguity occurred within a phonological phrase (consistent with previous research; e.g. '[un chat grincheux]', containing the potential competitor word 'chagrin', was processed more slowly than '[un chat drogué]' that contains no potential competitor). In contrast, when the lexical competitor straddled a phonological phrase boundary, there was no delay in lexical recognition (e.g., '[son grand chat] [grimpait. . .]', potential competitor 'chagrin' was not delayed relative to the non-ambiguous control). These results were observed with two different on-line tasks, word-monitoring and phoneme monitoring. They suggest that lexical access occurs within the domain of phonological phrases. We discuss the implications of these results for models of lexical access.
- ACFPeperkamp, S. (2004). Lexical exceptions in stress systems: Arguments from early language acquisition and adult speech perception. Language, 80, 98-126.Some, but not all, languages with fixed stress exhibit lexical exceptions to their stress rule. Under the assumption that lexical exceptions can occur in a language only if its native speakers can perceive stress contrasts, I argue that the presence of these exceptions depends on the age at which infants discover the stress rule of their language. If the stress regularity is easy to infer from the surface speech stream, then it will be acquired very early, and stress will not be encoded in the phonological representation of words in the mental lexicon; as a consequence, stress contrasts are not well perceived by adult speakers and lexical exceptions are excluded. If, by contrast, the regularity is difficult to infer, then it will be acquired relatively late, after the format of the phonological encoding of words has been fixed. That is, stress will be redundantly encoded in the mental lexicon, and lexical exceptions can thus be perceived and stored by adult speakers. A typological survey concerning the occurrence of exceptions in languages with fixed stress supports this proposal. A comparison with a metrical approach to exceptional stress is made, leading to a proposal about the division of labor between psycholinguistics and theoretical phonology.
- APeperkamp, S. (2003). Phonological acquisition: recent attainments and new challenges. Language and Speech, 46, 87-113.Infants' phonological acquisition during the first 18 months of life has been studied within experimental psychology for some 30 years. Current research themes include statistical learning mechanisms, early lexical development, and models of phonetic category perception. So far, linguistic theories have hardly been taken into account. These theories are based upon the assumption that there is a common core of innate phonological knowledge across speakers of all human languages, and they contain detailed proposals concerning phonological representations and the derivations by which abstract underlying forms are mapped onto concrete surface forms. It remains to be investigated experimentally if there is innate phonological knowledge and how the language-specific phonological grammar is acquired. In the present article, the contributions to this special issue are introduced, and an attempt is made to bridge the gap between phonological theory and experimental psychology. In particular, some recent experimental work is considered in the light of phonological theories and new research avenues are sketched. What might be innate, what needs to be acquired, and how this acquisition might take place are questions that are addressed with respect to several aspects of phonological knowledge, specifically segmental representations, phonotactics, phonological processes, and the architecture of the phonological grammar.
- AChristophe, A., Gout, A., Peperkamp, S. & Morgan, J. (2003). Discovering words in the continuous speech stream: the role of prosody. Journal of Phonetics, 31, 585-598.Finding words in sentences is made difficult by the absence of obvious acoustic markers at word boundaries, such as silent pauses. Recent experimental evidence suggests that both adults and infants are able to use prosodic boundary cues on-line to constrain lexical access. French adults performing a word detection task were slowed down by local lexical ambiguities within phonological phrases but not across a phonological phrase boundary (Christophe, Peperkamp, Pallier, Block & Mehler, J. Mem. Language (in revision)). Thirteen-month-old American infants who were trained to turn their heads upon hearing a bisyllabic word, such as 'paper', in a variant of the conditioned head-turning paradigm, responded more often to sentences that contained the target word than to sentences containing both its syllables separated by a phonological phrase boundary (Gout, Christophe, & Morgan, J. Mem. Language (in revision)). Taken together, these results suggest that both French adults and 13-month-old American infants perceive phonological phrase boundaries as natural word boundaries, and that they do not attempt lexical access on pairs of syllables which span such a boundary. We discuss the potential generalization of these results to other languages, the universality of prosodic boundary cues as well as their use in on-line syntactic analysis and syntax acquisition.
- CDupoux, E., Peperkamp, S. & Sebastián-Gallés, N. (2001). A robust method to study stress "deafness". Journal of the Acoustical Society of America, 110, 1606-1618.Previous research by Dupoux et al. [J. Memory Lang. 36, 406-421 (1997)] has shown that French participants, as opposed to Spanish participants, have difficulties in distinguishing nonwords that differ only in the location of stress. Contrary to Spanish, French does not have contrastive stress, and French participants are "deaf" to stress contrasts. The experimental paradigm used by Dupoux et al. (speeded ABX) yielded significant group differences, but did not allow for a sorting of individuals according to their stress "deafness." Individual assessment is crucial to study special populations, such as bilinguals or trained monolinguals. In this paper, a more robust paradigm based on a short-term memory sequence repetition task is proposed. In five French-Spanish cross-linguistic experiments, stress "deafness" is shown to crucially depend upon a combination of memory load and phonetic variability in F0. In experiments 3 and 4, nonoverlapping distribution of individual results for French and Spanish participants is observed. The paradigm is thus appropriate for assessing stress deafness in individual participants.
- ACDPeperkamp, S. & Mehler, J. (1999). Signed and spoken language: a unique underlying system? Language and Speech, 42, 333-346.Sign language has only recently become a topic of investigation in cognitive neuroscience and psycholinguistics. In this paper, we review research from these two fields; in particular, we compare spoken and signed language by looking at data concerning either cortical representations or early acquisition. As to cognitive neuroscience, we show that clinical neuropsychological data regarding sign language is partially inconsistent with imaging data. Indeed, whereas both clinical neuropsychology and imagery show the involvement of the left hemisphere in sign language processing, only the latter highlights the importance of the right hemisphere. We discuss several possible interpretations of these contrasting findings. As to psycholinguistics, we survey research on the earliest stages of the acquisition of spoken language, and consider these stages in the acquisition of sign language. We conjecture that under favorable circumstances, deaf children exploit sign input to gain entry into the language system with the same facility as hearing children do with spoken input. More data, however, are needed in order to gain a fuller understanding of the relation of different kinds of natural languages to both the underlying anatomical representations and their early acquisition.
- FPeperkamp, S. (1998). A representational analysis of secondary stress in Italian. Rivista di Linguistica, 9, 189-215.This paper surveys various analyses of secondary stress assignment in Italian and argues that they suffer from both descriptive and explanatory shortcomings. An alternative account will be developed, in which stress is not assigned by rule but is selected from a set of conceivable candidates by a system of constraints on representations. The stress patterns that are considered are those of words when pronounced in isolation. It will be shown that monomorphemic and derived words differ only in their stress patterns in that derived words are subject to the requirement that stress from the embedded word be preserved. This requirement, though, is overridden by constraints on metrical and prosodic wellformedness. Optional reranking of these requirements in the relevance hierarchy accounts for the variability of secondary stress which is found mainly in the southern varieties of Standard Italian. Finally, it will be argued that compounds generally consist of more than one stress domain, whereas adverbs ending in -mente show hybrid behavior; they cannot be classified either with derived words or with compounds.
- RCGuevara-Rukoz, A., E. Parlato-Oliveira, S. Yu, Y. Hirose, S. Peperkamp, & E. Dupoux (2017). Predicting epenthetic vowel quality from acoustics. Proceedings of Interspeech, 596-600.Past research has shown that sound sequences not permitted in our native language may be distorted by our perceptual system. A well-documented example is vowel epenthesis, a phenomenon by which listeners hallucinate non-existent vowels within illegal consonantal sequences. As reported in previous work, this occurs for instance in Japanese (JP) and Brazilian Portuguese (BP), languages for which the 'default' epenthetic vowels are /u/ and /i/, respectively. In a perceptual experiment, we corroborate the finding that the quality of this illusory vowel is language-dependent, but also that this default choice can be overridden by coarticulatory information present on the consonant cluster. In a second step, we analyse recordings of JP and BP speakers producing 'epenthesized' versions of stimuli from the perceptual task. Results reveal that the default vowel corresponds to the vowel with the most reduced acoustic characteristics and whose formants are acoustically closest to formant transitions present in consonantal clusters. Lastly, we model behavioural responses from the perceptual experiment with an exemplar model using dynamic time warping (DTW)-based similarity measures on MFCCs.RFTurnbull, R. & Peperkamp, S. (2016). What governs a language's lexicon? Determining the organizing principles of phonological neighbourhood networks. In: Cherifi, H., Gaito, S., Quattrociocchi, W., Sala, A. (eds.) Complex Networks & Their Applications V. Proceedings of the 5th International Workshop on Complex Networks and their Applications. Berlin: Springer International Publishing, 83-94.The lexicons of natural language can be characterized as a network of words, where each word is linked to phonologically similar words. These networks are called phonological neighbourhood networks (PNNs). In this paper, we investigate the extent to which observed properties of these networks are mathematical consequences of the definition of PNNs, consequences of linguistic restrictions on what possible words can sound like (phonotactics), or consequences of deeper cognitive constraints that govern lexical development. To test this question, we generate random lexicons, with a variety of methods, and derive PNNs from these lexicons. These PNNs are then compared to a real network. We conclude that most observed characteristics of PNNs are either intrinsic to the definition of PNNs, or are phonotactic effects. However, there are some properties—such as extreme assortativity by degree—which may reflect true cognitive organizing principles.CFZuraw, K. & Peperkamp, S. (2015). Aspiration and the gradient structure of English prefixed words. In: The Scottish Consortium for ICPhS 2015 (ed.) Proceedings of the 18th International Congress of Phonetic Sciences. Glasgow, UK: the University of Glasgow.Building on work examining the phonetic properties of prefixed and pseudoprefixed English words (mis-times vs. mistakes), we investigate aspiration in 110 English words beginning with mis- and dis-, produced by 16 native speakers of American English. We find that some items show considerable cross-speaker variation, but most are stable. Aspiration can occur even before an unstressed syllable (dis-[ph]ossessed), suggesting that not only word-initial but also some stem-initial voiceless stops are aspirated in English, either because of their prosodic position (prosodic-word-initial) or because of influence of the stem's freestanding pronunciation. Frequency factors correlate with an item's propensity to aspirate, supporting the view that whole-word and decomposed representations compete.CLev-Ari, S. & Peperkamp, S. (2014). Do people converge to the linguistic patterns of non-reliable speakers? Perceptual learning from non-native speakers. In: S. Fuchs, M. Grice, A. Hermes, L. Lancia, D. Mücke (eds.) Proceedings of the 10th International Seminar on Speech Production. 261-264.People's language is shaped by the input from the environment. The environment, however, offers a range of linguistic inputs that differ in their reliability. We test whether listeners accordingly weigh input from sources that differ in reliability differently. Using a perceptual learning paradigm, we show that listeners adjust their representations according to linguistic input provided by native but not by non-native speakers. This is despite the fact that listeners are able to learn the characteristics of the speech of both speakers. These results provide evidence for a disassociation between adaptation to the characteristic of specific speakers and adjustment of linguistic representations in general based on these learned characteristics. This study also has implications for theories of language change. In particular, it cast doubts on the hypothesis that a large proportion of non-native speakers in a community can bring about linguistic changes.AFort, M., Weiss, A., Martin, A. (Alexander) & Peperkamp, S. (2013). Looking for the bouba-kiki effect in prelexical infants. In: S. Ouni, F. Berthommier & A. Jesse (eds.) Proceedings of the 12th International Conference on Auditory-Visual Speech Processing. INRIA, 71-76.Adults and toddlers systematically associate certain pseudowords, such as ‘bouba’ and ‘kiki’, with round and spiky shapes, respectively. The ontological origin of this so-called bouba-kiki effect is unknown: it could be an unlearned aspect of perception, appear with language exposure, or only emerge with the ability to produce speech sounds (i.e., babbling). We report the results of three experiments with five- and six-month-olds that found no bouba-kiki effect at all. We discuss the consequences of these findings for the emergence of cross-modal associations in infant speech perception.ACristia, A. & Peperkamp, S. (2012). Generalizing without encoding specifics. Infants infer phonotactic patterns on sound classes. In: A. Biller, E. Chung & A. Kimball (eds.) Proceedings of the 36th Annual Boston University Conference on Language Development. Somerville, MA: Cascadilla Press, 126-138.Recent work suggests that infants can learn novel phonotactic regularities on the basis of brief exposure, and generalize them to novel sounds. An open question is how infants arrive at encoding class-wide patterns, without which no generalization could be observed. One possibility is that they track individual co-occurrence patterns and - based on these - posit a generalization. Alternatively, they might listen for general patterns without encoding sound-specific patterns. To adjudicate between these explanations, we tested French 6-month-olds infants. After familiarization to a phonotactic pattern on word-initial onsets, infants did not distinguish between novel items with the familiarized onsets and those with onsets that generalized the familiarization pattern, providing evidence in favor of the direct encoding of class-wide patterns. In a control experiment, infants did distinguish between novel items with onsets that generalized the familiarization pattern and those with onsets that violated it, showing that the null effect in the first experiment was not due to a lack of learning. Thus, infants are able to quickly form abstract generalizations without encoding sound-specific patterns.BDPeperkamp, S. & Bouchon, C. (2011). The relation between perception and production in L2 phonological processing. In: Proceedings of the 12th Annual Conference of the International Speech Communication Association (Interspeech 2011). Rundle Mall: Causal Productions, 161-164.Seventeen French-English bilinguals read aloud a set of English sentences and performed an ABX discrimination task that assessed their perception of the English /I/-/i/ contrast. Global nativelikeness in production correlated with pronunciation accuracy for the vowels /I/ and /i/, and both production measures correlated with self-estimated pronunciation skills. However, performance on the perception task did not correlate with either global nativelikeness or /I,i/ pronunciation accuracy. These results are discussed in light of theories about the relation between perception and production in L2 phonological processing.ABoruta, L., Peperkamp, S., Crabbé, B. & Dupoux, E. (2011). Testing the robustness of word segmentation with realistic input: effects of linguistic diversity and phonetic variation. In: Proceedings of the 2011 Workshop on Cognitive Modeling and Computational Linguistics, ACL 2011. Stroudsburg, PA: The Association for Computational Linguistics, 1-9.Models of the acquisition of word segmentation are typically evaluated using phonemically transcribed corpora. Accordingly, they implicitly assume that children know how to undo phonetic variation when they learn to extract words from speech. Moreover, whereas models of language acquisition should perform similarly across languages, evaluation is often limited to English samples. Using child-directed corpora of English, French and Japanese, we evaluate the performance of state-of-the-art statistical models given inputs where phonetic variation has not been reduced. To do so, we measure segmentation robustness across different levels of segmental variation, simulating systematic allophonic variation or errors in phoneme recognition. We show that these models do not resist an increase in such variations and do not generalize to typologically different languages. From the perspective of early language acquisition, the results strengthen the hypothesis according to which phonological knowledge is acquired in large part before the construction of a lexicon.BSkoruppa, K., Lambrechts, A. & Peperkamp, S. (2011). The role of phonetic distance in the acquisition of phonological alternations. In: Proceedings of the 39th North Eastern Linguistics Conference. Somerville, MA: Cascadilla Press, 717-729.Using an artificial language-learning paradigm with a production task, we examine whether the phonetic distance between alternating sounds has an effect on the learning of phonological alternations by adults, and if so, if the effect is discrete or gradient. To this end, we compare the learning of alternations that involve one, two, or three feature changes. We find that alternations that involve one feature change are learned faster and better than those involving two or three feature changes. No difference is observed between the latter two. These results are discussed in light of theories on the nature and origin of phonetic naturalness in phonology.ESan Giacomo, M. & Peperkamp, S. (2008). Presencia del español en náhuatl: estudio sociolingüístico de la adaptación de préstamos. In: M. Westmoreland & J. Thomas (eds.) Selected Proceedings of the Fourth Workshop on Spanish Sociolinguistics. Somerville, MA: Cascadilla Press, 149-156.This study analyzes the effects of sociolinguistic factors on the adaptations and non-adaptations of Spanish borrowings into Nahuatl. Fieldwork was carried out in Tagcotepec, a Nahuatl community of 500 inhabitants in Puebla, Mexico. Data were collected using a stratified sample of 71 speakers, representative of the sociolinguistic traits of the community, in terms of age, sex, level of bilingualism, and location within the village. The compiled database consisted of 671 loanwords for a total of 4631 tokens. The mean percentage of adaptation was 17%, and a multivariate analysis of the data reveals that adaptation is more likely if the speaker lives in the remote part of the village, is in the older age group, is a man, talks to friends and relatives, and if the loanword has a high frequency of use.ALe Calvez, R., Peperkamp, S. & Dupoux, E. (2007). Bottom-up learning of phonemes: A computational study. Proceedings of the Second European Cognitive Science Conference, 167-172. [existe en français : Le Calvez, R., S. Peperkamp & E. Dupoux (2007) Apprentissage bottom-up des phonèmes : une étude computationnelle. Mathématiques et Sciences Humaines, 180, 101-114.]We present a computational evaluation of a hypothesis according to which distributional information is sufficient to acquire allophonic rules (and hence phonemes) in a bottom-up fashion. The hypothesis was tested using a measure based on information theory that compares distributions. The test was conducted on several artificial language corpora and on two natural corpora containing transcriptions of speech directed to infants from two typologically distant languages (French and Japanese). The measure was complemented with three filters, one concerning the statistical reliability due to sample size and two concerning the following universal properties of allophonic rules: constituents of an allophonic rule should be phonetically similar, and allophonic rules should be assimilatory in nature.BPeperkamp, S., Skoruppa, K. & Dupoux, E. (2006). The role of phonetic naturalness in phonological rule acquisition. In: D. Bamman, T. Magnitskaia & C. Zaller (eds.) Proceedings of the 30th Annual Boston University Conference on Language Development. Somerville, MA: Cascadilla Press, 464-475.In previous work using an artificial language-learning paradigm with a phrase-picture matching task, we found that adults learn unnatural, arbitrary, phonological rules to the same extent as natural, assimilatory, ones. In the present article we use the same stimuli but a more natural task, i.e. picture naming, and obtain an unambiguous effect of naturalness: natural rules are learned better than unnatural ones. We speculate that the difference between the two experiments is due to differences in task difficulty. Overall, the present results add to the growing body of evidence concerning the role of phonetic naturalness in phonological learning.EPeperkamp, S. (2005). A psycholinguistic theory of loanword adaptations. In: M. Ettlinger, N. Fleischer & M. Park-Doob (eds.) Proceedings of the 30th Annual Meeting of the Berkeley Linguistics Society. Berkeley, CA: The Society, 341-352.Phonologists have long held an interest in loanword adaptations, that is in the transformations that apply to words when they are borrowed into a foreign language. Within constraint-based frameworks, it has been argued that loanword adaptations are in conformity with the native phonology, and even that they provide insight into it, revealing the relative ranking of faithfulness constraints that would otherwise remain 'hidden'. Against this view, I argue that loanword adaptations are not computed by the phonological grammar of the borrowing language. First, I show that not all loanword adaptations are in accordance with the native phonology. Second, I argue that separating these problematic cases from the remaining loanword adaptations and treating them differently, by making appeal to phonetic and/or perceptual arguments, yields an ad hoc distinction between phonological and non-phonological adaptations. Finally, I propose that a principled solution lies with the hypothesis that all loanword adaptations are phonetically minimal transformations that apply during speech perception. This hypothesis is motivated independently by psycholinguistic data concerning the perception of non-native sound structures.CEVendelin, I. & Peperkamp, S. (2004). Evidence for phonetic adaptation of loanwords: an experimental study. Actes des Journées d'Etudes Linguistiques, 127-131. [superseded by Peperkamp, Vendelin & Nakamura (2010)]EPeperkamp, S. & Dupoux, E. (2003). Reinterpreting loanword adaptations: The role of perception. In: M.J. Solé, D. Recasens & J. Romero (éds.) Proceedings of the 15th International Congress of Phonetic Sciences. Adelaide: Causal Productions, 367-370.Standard phonological accounts of loanword adaptations state that the inputs to the adaptations are constituted by the surface forms of the words in the source language and that the adaptations are computed by the phonological grammar of the borrowing language. In processing terms, this means that in perception, the phonetic form of the source words is faithfully copied onto an abstract underlying form, and that adaptations are produced by the standard phonological processes in production. We argue that this is at odds with speech perception models and propose that loanword adaptations take place in perception and are defined as phonetically minimal transformations.BPeperkamp, S., Pettinato, M. & Dupoux, E. (2003). Allophonic variation and the acquisition of phoneme categories. In: B. Beachley, A. Brown & F. Conlin (eds.) Proceedings of the 27th Annual Boston University Conference on Language Development. Volume 2. Sommerville, MA: Cascadilla Press, 650-661.We report two experiments concerning the perception and the acquisition of phonemic versus allophonic contrasts, respectively. In the first experiment, we examine whether French adults exhibit differences in the perception of these two types of contrast. We find that a native allophonic contrast is very well discriminated when presented in isolation, but very poorly discriminated compared to a control phonemic contrast when embedded in context. In the second experiment, we use a training procedure with stimuli in context to explore whether adult listeners can rely upon distributional information in order to construct abstract phoneme categories. We find only a numerically small amount of learning overall and limited evidence for sensitivity to complementary distributions of allophonic variants during learning. These results are discussed in light of theories on statistical learning mechanisms in phonological acquisition.DPeperkamp, S., Dupoux, E. & Sebastián-Gallés, N. (1999). Perception of stress by French, Spanish, and bilingual subjects. Proceedings of EuroSpeech '99, Vol. 6, 2683-2686. [superseded by Dupoux, Peperkamp & Sebastián-Gallés (2010)]FPeperkamp, S. (1995). Enclitic stress in Romance. In: A. Dainora, R. Hemphill, B. Luka, B. Need & S. Pargman (eds.) Papers from the 31st Regional Meeting of the Chicago Linguistic Society, Volume 2: The Parasession on Clitics. Chicago: Chicago Linguistic Society, 234-249.As in many other Romance languages, main word stress in Neapolitan falls on one of the word's last three syllables. Although clitics are inherently stressless, a string consisting of a verb and two enclitics surfaces with two main word stresses, one on the verb and one on the first clitic. If only one clitic is attached, however, no stress falls on the clitic. In this article, it is argued that encliticization in Neapolitan gives rise to recursive prosodic word structure. In this structure, a disyllabic foot can be built if two clitics are present but not is only one clitic is present, thus accounting for the facts of enclitic stress. Furthermore, it is shown that permutation of the constraint ranking yields representations that make different predictions concerning stress assignment in encliticized forms. These predictions are shown to be borne out by two other languages spoken in Italy, i.e. Lucanian and Standard Italian.
- CEPeperkamp, S. (2015). Phonology versus phonetics in loanword adaptations: A reassessment of English vowels in French. In: J. Romero & M. Riera (eds.) The Phonetics-Phonology Interface. Representations and Methodologies. Amsterdam: John Benjamins, 71-90.The question of whether loanword adaptation is based on phonologic or phonetic proximity has been widely debated. This article focuses on the adaptation of English vowels in French, and argues that on-line adaptations are based on perceived phonetic proximity. An experiment with a forced-choice identification task assessed French listeners' perception of English vowels presented both within and spliced out of CVC syllables; the results were compared to the on-line adaptations of the same vowels in the same consonantal contexts produced previously by French speakers (Vendelin & Peperkamp 2006). It was found that vowel identification in the two conditions differ, and that the on-line adaptations in Vendelin & Peperkamp (2006) are reflected more closely by the results in the condition with vowels presented in context. These results support the hypothesis that the on-line adaptation of English vowels into French is based on phonetic, not phonological, proximity. They also show that phonetic variability due to coarticulation influences perception and hence that consonantal context should be controlled for in cross-linguistic vowel comparisons.
- CDEFMartin, A. (Andrew) & Peperkamp, S. (2011). Speech perception and phonology. In: M. van Oostendorp, C. Ewen, E. Hume & K. Rice (eds.) Companion to Phonology. Volume IV. Hoboken, N.J.: Wiley-Blackwell, 2234-2256.The task of speech perception involves converting a continuous, information-rich waveform into a more abstract representation. This mapping process is heavily language-dependent - every language divides up acoustic space differently, and the mapping is distorted by context-dependent phonological rules. This is not an easy job, but it is made easier in two complementary respects. During the first year of life the human perceptual apparatus is gradually optimized to better perceive the distinctions that are crucial in the ambient language's phonological system while ignoring irrelevant variation, and phonological systems themselves are optimized from the perspective of human perception. This two-way interaction, in which perception adapts to phonology and phonology to perception, has long been of interest to phonologists, but only in recent decades have the tools necessary to explore the connection between the two become available. In this chapter we provide an overview of the debates that have arisen around each issue, as well as the research that bears on each debate We first discuss how phonology influences speech perception, both in the native language and in non-native ones, and how second language perception relates to loanword adaptations. We then address the question of how perception influences phonology, beginning with an overview of the relevant typological data, and concluding with a comparison of theoretical approaches to the data.
- ABCRamus, F., Peperkamp, S., Christophe, A., Jacquemot, C., Kouider, S. & Dupoux, E. (2010). A psycholinguistic perspective on the acquisition of phonology. In: C. Fougeron, B. Kühnert, M. D'Imperio & N. Vallé (eds.) Laboratory Phonology 10. Berlin: Mouton de Gruyter, 311-340.This paper discusses the target articles by Fikkert, Vihman, and Goldrick & Larson, which address diverse aspects of the acquisition of phonology. These topics are examined using a wide range of tasks and experimental paradigms across different ages. Various levels of processing and representation are thus involved. The main point of the present paper is that such data can be coherently interpreted only within a particular information-processing model that specifies in sufficient detail the different levels of processing and representation. We first present the basic architecture of a model of speech perception and production, justifying it with psycholinguistic and neuropsychological data. We then use this model to interpret data from the target articles relative to the acquisition of phonology.
- BCPeperkamp, S. & Dupoux, E. (2007). Learning the mapping from surface to underlying representations in an artificial language. In: J. Cole & J. Hualde (eds.) Laboratory Phonology 9. Berlin: Mouton de Gruyter, 315-338.When infants acquire their native language they not only extract language-specific segmental categories and the words of their language, they also learn the underlying form of these words. This is difficult because words can have multiple phonetic realizations, according to the phonological context. In a series of artificial language-learning experiments with a phrase-picture matching task, we consider the respective contributions of word meaning and distributional information for the acquisition of underlying representations in the presence of an allophonic rule. We show that on the basis of semantic information, French adults can learn to map voiced and voiceless stops or fricatives onto the same underlying phonemes, whereas in their native language voicing is phonemic in all obstruents. They do not extend this knowledge to novel stops or fricatives, though. In the presence of distributional cues only, learning is much reduced and limited to the words subjects are trained on. We also test if phonological naturalness plays a role in this type of learning, and find that if semantic information is present, French adults can learn to map different segments onto a single underlying phoneme even if the mappings are highly unnatural. We discuss our findings in light of current statistical learning approaches to language acquisition.
- BDDarcy, I., Peperkamp, S. & Dupoux, E. (2007). Bilinguals play by the rules: perceptual compensation for assimilation in late L2-learners. In: J. Cole & J. Hualde (eds.) Laboratory Phonology 9. Berlin: Mouton de Gruyter, 411-442.Phonological rules introduce variation in word forms that listeners have to compensate for. We previously showed that compensation for phonological variation in perception is driven by language-specific mechanisms. In particular, English speakers compensate more for place assimilation than for voicing assimilation, whereas the reverse holds for French speakers. English indeed has a rule of place assimilation, whereas French has a rule of voicing assimilation. In the present study, we explore the patterns of compensation for assimilation in English learners of French and in French learners of English. We use the same design and stimuli as Darcy et al. (2009); in this design, listeners are engaged in a word detection task on sentences containing occurrences of both place assimilation and voicing assimilation. We test British English and American English learners of French as well as French learners of American English on both their native language (L1) and their second language (L2). The results show that beginners interpret their L2 in exactly the same way as their L1: they apply the native compensation pattern to both languages. Advanced learners, by contrast, succeed in compensating for the non-native assimilation rule in their L2, while keeping the native compensation pattern for L1; as little or no interference from L2 on L1 is observed for these learners, we conclude that two separate systems of compensation for phonological processes can co-exist.
- ACPeperkamp, S. & Dupoux, E. (2002). A typological study of stress 'deafness'. In: C. Gussenhoven & N. Warner (eds.) Laboratory Phonology 7. Berlin: Mouton de Gruyter, 203-240.Previous research has shown that native speakers of French, as opposed to those of Spanish, exhibit stress "deafness", i.e. have difficulties distinguishing stress contrasts. In French, stress is non-contrastive, while in Spanish, stress is used to make lexical distinctions. We examine three other languages with non-contrastive stress, Finnish, Hungarian and Polish. In two experiments with a short-term memory sequence repetition task, we find that speakers of Finnish and Hungarian are like French speakers (i.e. exhibit stress "deafness"), but not those of Polish. We interpret these findings in the light of an acquisition framework, that states that infants decide whether or not to keep stress in their phonological representation during the first two years of life, based on information extractable from utterance edges. In particular, we argue that Polish infants, unlike French, Finnish and Hungarian ones, cannot extract the stress regularity of their language on the basis of what they have already learned. As a consequence, they keep stress in their phonological representation, and as adults, they do not have difficulties in distinguishing stress contrasts.
- ACDupoux, E. & Peperkamp, S. (2002). Fossil markers of language development: phonological 'deafnesses' in adult speech processing. In: J. Durand & B. Laks (eds.) Phonetics, Phonology, and Cognition. Oxford: Oxford University Press, 168-190.The sound pattern of the language(s) we have heard as infants affects the way in which we perceive linguistic sounds as adults. Typically, some foreign sounds are very difficult to perceive accurately, even after extensive training. For instance, native speakers of French have troubles distinguishing foreign words that differ only in the position of main stress, French being a language in which stress is not contrastive. In this paper, we propose to explore the perception of foreign sounds cross-linguistically in order to understand the processes that govern early language acquisition. Specifically, we propose to test the hypothesis that early language acquisition begins by using only regularities that infants can observe in the surface speech stream (Bottom-Up Bootstrapping), and compare it with the hypothesis that they use all possible sources of information, including, for instance, word boundaries (Interactive Bootstrapping). We set up a research paradigm using the stress system, since it allows to test the various options at hand within a single test procedure. We distinguish four types of regular stress systems the acquisition of which requires different sources of information. We show that the two hypotheses make contrastive predictions as to the pattern of stress perception of adults in these four types of languages. We conclude that cross-linguistic research of adults speech perception, when coupled with detailed linguistic analysis, can be brought to bear on important issues of language acquisition.
- APeperkamp, S. & Dupoux, E. (2002). Coping with phonological variation in early lexical acquisition. In: I. Lasser (ed.) The Process of Language Acquisition. Frankfurt: Peter Lang, 359-385.Mapping word forms onto their corresponding meanings is one of the most complex tasks that young infants acquiring their native language have to perform. One of the challenges they meet in this respect is that words can surface with different phonetic forms due to the application of postlexical phonological processes; that is, surface word forms exhibit what we call phonological variation. In this article, we examine if and how infants that do not have a lexicon might undo phonological variation, i.e. deduce which phonological processes apply and infer unique underlying word forms that will constitute lexical entries. Two types of phonological rules are considered, which introduce variation in word forms and morphemes, respectively. As to the former, we propose a learning mechanism that deduces which rule applies and infers underlying phonemes and word forms, based on an examination of the distribution of either surface segments or surface word forms. As to the latter, we show that although the rules that introduce morpheme variation can be deduced in the absence of semantic knowledge, no underlying forms can be inferred. These forms, in fact, can be found only if morphological alternations are taken into account.
- FPeperkamp, S. (1997). Output-to-output identity in word level phonology. In: J. Coerts & H. de Hoop (eds.) Linguistics in the Netherlands 1997. Amsterdam: John Benjamins, 159-170.Recent developments in optimality theory have led to a revision of the role of faithfulness. In particular, it is argued that output candidates can be compared not only with their underlying inputs by means of input-to-output constraints, but also with the surface form of paradigmatically related words by means of output-to-output constraints. Many phonological effects of under- or overapplication formerly attributed to the cycle or to level ordering receive a straightforward one-level analysis in this type of paradigmatic phonology. In this paper, I consider several cases of under- and overapplication in the phonology of Italian, Spanish, Catalan and Dutch. I argue that analyses based on output-to-output faithfulness constraints lead to a variety of problems, which do not arise in accounts based on rule ordering and the definition of rule domains.
- FPeperkamp, S. (1997). The prosodic structure of compounds. In: G. Matos, M. Miguel, I. Duarte & I. Faria (eds.) Interfaces in Linguistic Theory. Lisbon: APL / Colibri, 259-279.Prototypically, compounds consist of two independent words. Many languages, however, also have compounds that are composed of a stem followed by a word, or by two stems. This article addresses the question as to how these different morphological types of compounds are mapped onto prosodic words in Italian, a language that allows for all three morphological compound types.. Two phonological rules that have the prosodic word as domain of application, vowel raising and intervocalic s-voicing, serve as diagnostics for prosodic word status. It is shown that certain compound types exhibit hybrid behavior with regard to these rules, and that previous approaches concerning the prosodic structure of compounds that assume the Strict Layer Hypothesis are unable to account for these data. Alternatively, it is argued that the data can be accommodated if recursive prosodic words are permitted.
- FPeperkamp, S. (1996). On the prosodic representation of clitics. In: U. Kleinhenz (ed.) Interfaces in Phonology. Berlin: Akademie Verlag, 104-128.This article brings supporting evidence for the hypothesis advanced in previous work that clitics can and should be represented in the prosodic hierarchy without the postulation of the category clitic group. First, cases that have been argued to show the need for the clitic group are reanalyzed without reference to a category clitic group. Second, a novel argument against the clitic group is developed. That is, based on data regarding stress assignment in verb plus enclitic sequences in three languages spoken in Italy, it is argued that Romance clitics are not incorporated into prosodic constituent structure in a uniform manner. Specifically, each of the languages under consideration adopts one of the following strategies for the prosodization of clitics: adjunction to the prosodic word, incorporation into the phonological phrase, or incorporation into the prosodic word by restructuring. This interlinguistic variation is derived within Optimality Theory by the permutation of constraints on prosodic constituency and the mapping from morphosyntactic onto prosodic structure.
- FPeperkamp, S. (1995). Prosodic constraints in the derivational morphology of Italian. In: G. Booij & J. van Marle (eds.) Yearbook of Morphology 1994. Dordrecht: Kluwer Academic Publishers, 207-244.Italian has both a series of derivational prefixes and a series of derivational suffixes. Word-final vowels typically do not surface before vowel-initial suffixes. By contrast, if a vowel-final prefix attaches to a vowel-initial word, generally both vowels surface. This article analyzes the asymmetry between Italian prefixation and suffixation within Optimality Theory. In particular, it is argued that suffixation is stem-based, and that a single ranking of prosodic constraints governs both prefixation and suffixation.
- ABabineau, M. & Peperkamp, S. (2017). L'acquisition du langage chez le bébé. In: L'éducation à la lumière des neurosciences. Actes du 12ème colloque Petite Enfance. Genève : Service de la petite enfance, 55-62.
- XPeperkamp, S. (2010). Le langage. Introduction. In: H. Zwirn & G. Weisbuch (eds.) Qu'appelle-t-on aujourd'hui les sciences de la complexité ? Langages, réseaux, marchés, territoires. Paris : Vuibert, 11-14.
- ACPeperkamp, S. (2007). La perception de la parole et l'acquisition de la phonologie. Rééducation Orthophonique 229, 3-16.
- APeperkamp, S., ed. (2003). Phonological Acquisition, special double issue of Language and Speech.
- FPeperkamp, S. (1999). Prosodic words. GLOT International 4, 15-16. [A summary of my dissertation]
- FPeperkamp, S. (1997). Prosodic Words. HIL dissertations 34. The Hague: Holland Academic Graphics.Prosodic Words examines phonological aspects of derivation, compounding and cliticization, with particular regard to the definition of the prosodic word. Based on data from various languages, including Italian and Spanish, the prosodization of derivational affixes, compound elements, and clitics is analyzed. Attention is paid, furthermore, to the consequences of phrasal resyllabification for the structure of the prosodic word, as well as to several morphological issues regarding derivation and compounding. The proposals are set within the constraint-based framework of optimality theory. In particular, this approach is argued to allow for a constrained account of the occurrence of marked representations in prosodic phonology.