Diminutives facilitate word segmentation in natural speech: Cross-linguistic evidence

Final-syllable invariance is characteristic of diminutives (e.g., doggie), which are a pervasive feature of the child-directed speech registers of many languages. Invariance in word endings has been shown to facilitate word segmentation (Kempe, Brooks, & Gillis, 2005) in an incidental-learning paradigm in which synthesized Dutch pseudonouns were used. To broaden the cross-linguistic evidence for this invariance effect and to increase its ecological validity, adult English speakers (n=276) were exposed to naturally spoken Dutch or Russian pseudonouns presented in sentence contexts. A forced choice test was given to assess target recognition, with foils comprising unfamiliar syllable combinations in Experiments 1 and 2 and syllable combinations straddling word boundaries in Experiment 3. A control group (n=210) received the recognition test with no prior exposure to targets. Recognition performance improved with increasing final-syllable rhyme invariance, with larger increases for the experimental group. This confirms that word ending invariance is a valid segmentation cue in artificial, as well as naturalistic, speech and that diminutives may aid segmentation in a number of languages.     

Newborns are sensitive to multiple cues for word segmentation in continuous speech

Before infants can learn words, they must identify those words in continuous speech. Yet, the speech signal lacks obvious boundary markers, which poses a potential problem for language acquisition (Swingley, Philos Trans R Soc Lond. Series B, Biol Sci 364 (1536), 3617–3632, 2009). By the middle of the first year, infants seem to have solved this problem (Bergelson & Swingley, Proc Natl Acad Sci 109 (9), 3253–3258, 2012; Jusczyk & Aslin, Cogn Psychol 29 , 1–23, 1995), but it is unknown if segmentation abilities are present from birth, or if they only emerge after sufficient language exposure and/or brain maturation. Here, in two independent experiments, we looked at two cues known to be crucial for the segmentation of human speech: the computation of statistical co‐occurrences between syllables and the use of the language's prosody. After a brief familiarization of about 3 min with continuous speech, using functional near‐infrared spectroscopy, neonates showed differential brain responses on a recognition test to words that violated either the statistical (Experiment 1) or prosodic (Experiment 2) boundaries of the familiarization, compared to words that conformed to those boundaries. Importantly, word recognition in Experiment 2 occurred even in the absence of prosodic information at test, meaning that newborns encoded the phonological content independently of its prosody. These data indicate that humans are born with operational language processing and memory capacities and can use at least two types of cues to segment otherwise continuous speech, a key first step in language acquisition.     

中文阅读预视加工中的词频和预测性效应及其对词切分的启示:基于眼动的证据

研究采用眼动随动显示技术考察中文阅读预视加工中的词汇加工问题。前三项实验发现,剥夺预视加工的掩蔽条件、正确提示词n+1右侧边界的掩蔽条件以及不能提示词n+1右侧边界的掩蔽条件都不影响词频效应,说明中文读者对词n+1处文字的预视加工达不到词汇水平。实验4考察剥夺预视加工的掩蔽条件、提示词n+1右侧边界的掩蔽条件对预测性效应的影响,结果发现,剥夺预视加工完全消除预测性效应,提示词n+1右侧边界则减少预测性效应,说明对词汇的预期加工是中文读者切分词n+1的参考线索。综合4项实验结果可知,中文读者较难通过自下而上的文字识别切分词n+1,自上而下的词汇预期则是切分词n+1的加工形式。     

Diminutives in child-directed speech supplement metric with distributional word segmentation cues

In two experiments, we explored whether diminutives (e.g.,birdie, Patty, bootie), which are characteristic of child-directed speech in many languages, aid word segmentation by regularizing stress patterns and word endings. In an implicit learning task, adult native speakers of English were exposed to a continuous stream of synthesized Dutch nonsense input comprising 300 randomized repetitions of six bisyllabic target nonwords. After exposure, the participants were given a forced choice recognition test to judge which strings had been present in the input. Experiment 1 demonstrated that English speakers used trochaic stress to isolate strings, despite being unfamiliar with Dutch phonotactics. Experiment 2 showed benefits from invariance introduced by affricates, which are typically found at onsets of final syllables in Dutch diminutives. Together, the results demonstrate that diminutives contain prosodic and distributional features that are beneficial for word segmentation.     

A computational model of word segmentation from continuous speech using transitional probabilities of atomic acoustic events

Word segmentation from continuous speech is a difficult task that is faced by human infants when they start to learn their native language. Several studies indicate that infants might use several different cues to solve this problem, including intonation, linguistic stress, and transitional probabilities between subsequent speech sounds. In this work, a computational model for word segmentation and learning of primitive lexical items from continuous speech is presented. The model does not utilize any a priori linguistic or phonemic knowledge such as phones, phonemes or articulatory gestures, but computes transitional probabilities between atomic acoustic events in order to detect recurring patterns in speech. Experiments with the model show that word segmentation is possible without any knowledge of linguistically relevant structures, and that the learned ungrounded word models show a relatively high selectivity towards specific words or frequently co-occurring combinations of short words.     

Stress changes the representational landscape: evidence from word segmentation

Over the past couple of decades, research has established that infants are sensitive to the predominant stress pattern of their native language. However, the degree to which the stress pattern shapes infants' language development has yet to be fully determined. Whether stress is merely a cue to help organize the patterns of speech or whether it is an important part of the representation of speech sound sequences has still to be explored. Building on research in the areas of infant speech perception and segmentation, we asked how several months of exposure to the target language shapes infants' speech processing biases with respect to lexical stress. We hypothesize that infants represent stressed and unstressed syllables differently, and employed analyses of child-directed speech to show how this change to the representational landscape results in better distribution-based word segmentation as well as an advantage for stress-initial syllable sequences. A series of experiments then tested 9- and 7-month-old infants on their ability to use lexical stress without any other cues present to parse sequences from an artificial language. We found that infants adopted a stress-initial syllable strategy and that they appear to encode stress information as part of their proto-lexical representations. Together, the results of these studies suggest that stress information in the ambient language not only shapes how statistics are calculated over the speech input, but that it is also encoded in the representations of parsed speech sequences.     

Infants' sensitivity to allophonic cues for word segmentation

A series of four experiments was conducted to determine whether English-learning infants can use allophonic cues to word boundaries to segment words from fluent speech. Infants were familiarized with a pair of two-syllable items, such as nitrates and night rates and then were tested on their ability to detect these same words in fluent speech passages. The presence of allophonic cues to word boundaries did not help 9-month-olds to distinguish one of the familiarized words from an acoustically similar foil. Infants familiarized with nitrates were just as likely to listen to a passage about night rates as they were to listen to one about nitrates. Nevertheless, when the passages contained distributional cues that favored the extraction of the familiarized targets, 9-month-olds were able to segment these items from fluent speech. By the age of 10.5 months, infants were able to rely solely on allophonic cues to locate the familiarized target words in passages. We consider what implications these findings have for understanding how word segmentation skills develop.     

The contribution of orthography to spoken word production: Evidence from Mandarin Chinese

A recent debate in the language production literature concerns the influence of a word’s orthographic information on spoken word production and the extent to which this influence is modulated by task context. In the present study, Mandarin Chinese participants produced sets of words that shared orthography (O+P−), phonology (O−P+), or orthography and phonology (O+P+), or were unrelated (O−P−), in the context of a reading, associative naming, or picture naming task. Shared phonology yielded facilitation effects in all three tasks, but only in the reading task was this phonological effect modulated by shared orthography. Shared orthography by itself (O+P−) revealed inhibitory effects in reading, but not in associative naming or in picture naming. These results suggest that a word’s orthography information influences spoken word production only in tasks that rely heavily on orthographic information.     

Infants’ statistical word segmentation in an artificial language is linked to both parental speech input and reported production abilities

Individual variability in infant's language processing is partly explained by environmental factors, like the quantity of parental speech input, as well as by infant‐specific factors, like speech production. Here, we explore how these factors affect infant word segmentation. We used an artificial language to ensure that only statistical regularities (like transitional probabilities between syllables) could cue word boundaries, and then asked how the quantity of parental speech input and infants’ babbling repertoire predict infants’ abilities to use these statistical cues. We replicated prior reports showing that 8‐month‐old infants use statistical cues to segment words, with a preference for part‐words over words (a novelty effect). Crucially, 8‐month‐olds with larger novelty effects had received more speech input at 4 months and had greater production abilities at 8 months. These findings establish for the first time that the ability to extract statistical information from speech correlates with individual factors in infancy, like early speech experience and language production. Implications of these findings for understanding individual variability in early language acquisition are discussed.     

Testing the associative-link hypothesis in immediate serial recall: Evidence from word frequency and word imageability effects

Two immediate serial recall experiments were conducted to test the associative-link hypothesis (Stuart & Hulme, 2000). We manipulated interitem association by varying the intralist latent semantic analysis (LSA) cosines in our 7-item study word lists, each of which consists of high- or low-frequency words in Experiment 1 and high- or low-imageability words in Experiment 2. Whether item recall performance was scored by a serial-recall or free-recall criterion, we found main effects of interitem association, word imageability, and word frequency. The effect of interitem association also interacted with the word frequency effect, but not with the word imageability effect. The LSA-cosinexword frequency interaction occurred in the recency, but not primacy, portion of the serial position curve. The present findings set explanatory boundaries for the associative-link hypothesis and we argue that both item- and associative-based mechanisms are necessary to account for the word frequency effect in immediate serial recall.     

Testing the associative-link hypothesis in immediate serial recall: Evidence from word frequency and word imageability effects

Two immediate serial recall experiments were conducted to test the associative-link hypothesis (Stuart & Hulme, 2000 Stuart, G. and Hulme, C. 2000. The effects of word co-occurrence on short-term memory: Associative-links in long-term memory affect short-term memory performance. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26: 796–802. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). We manipulated interitem association by varying the intralist latent semantic analysis (LSA) cosines in our 7-item study word lists, each of which consists of high- or low-frequency words in Experiment 1 and high- or low-imageability words in Experiment 2. Whether item recall performance was scored by a serial-recall or free-recall criterion, we found main effects of interitem association, word imageability, and word frequency. The effect of interitem association also interacted with the word frequency effect, but not with the word imageability effect. The LSA-cosine×word frequency interaction occurred in the recency, but not primacy, portion of the serial position curve. The present findings set explanatory boundaries for the associative-link hypothesis and we argue that both item- and associative-based mechanisms are necessary to account for the word frequency effect in immediate serial recall.     

The effects of word length on memory for pictures: Evidence for speech coding in young children

In a series of three experiments children aged from 4 to 10 years old were presented with a serial recall task with pictures of common objects which had short or long names. Children of all ages showed consistently better recall of pictures with short names. This effect occurred without the pictures being named at presentation and was abolished by articulatory suppression. It is concluded, in contrast to some earlier studies, that children as young as 4 years are able to use a speech code as a means of memorizing pictures.     

Semantic effects in word naming: Evidence from English and Japanese Kanji

Three experiments investigated whether reading aloud is affected by a semantic variable, imageability. The first two experiments used English, and the third experiment used Japanese Kanji as a way of testing the generality of the findings across orthographies. The results replicated the earlier findings that readers were slower and more error prone in reading low-frequency exception words when they were low in imageability than when they were high in imageability (Strain, Patterson, & Seidenberg, 1995). This result held for both English and Kanji even when age of acquisition was taken into account as a possible confounding variable, and the imageability effect was stronger in Kanji compared to English.     

Phonological coding in word reading: Evidence from hearing and deaf readers

The ability of prelingually, profoundly deaf readers to access phonological information during reading was investigated in three experiments. The experiments employed a task, developed by Meyer, Schvaneveldt, and Ruddy (1974), in which lexical decision response times (RTs) to orthographically similar rhyming (e.g., WAVE-SAVE) and nortrhyming (e.g., HAVE-CAVE) word pairs were compared with RTs to orthographically and phonologically dissimilar control word pairs. The subjects of the study were deaf college students and hearing college students. In Experiments 1 and 2, in which the nonwords were pronounceable, the deaf subjects, like the hearing subjects, were facilitated in their RTs to rhyming pairs, but not to nonrhyming pairs. In Experiment 3, in which the nonwords were unpronounceable, both deaf and hearing subjects were facilitated in their RTs to both rhyming and nonrhyming pairs, with the facilitation being significantly greater for the rhyming pairs. These results indicate that access to phonological information is possible despite prelingual and profound hearing impairment. As such, they run counter to claims that deaf individuals are limited to the use of visual strategies in reading. Given the impoverished auditory, experience of such readers, these results suggest that the use of phonological information need not be tied to the auditory modality.     

Speaking rate from proximal and distal contexts is used during word segmentation

A series of eye-tracking and categorization experiments investigated the use of speaking-rate information in the segmentation of Dutch ambiguous-word sequences. Juncture phonemes with ambiguous durations (e.g., [s] in 'eens (s)peer,' "once (s)pear," [t] in 'nooit (t)rap,' "never staircase/quick") were perceived as longer and hence more often as word-initial when following a fast than a slow context sentence. Listeners used speaking-rate information as soon as it became available. Rate information from a context proximal to the juncture phoneme and from a more distal context was used during on-line word recognition, as reflected in listeners' eye movements. Stronger effects of distal context, however, were observed in the categorization task, which measures the off-line results of the word-recognition process. In categorization, the amount of rate context had the greatest influence on the use of rate information, but in eye tracking, the rate information's proximal location was the most important. These findings constrain accounts of how speaking rate modulates the interpretation of durational cues during word recognition by suggesting that rate estimates are used to evaluate upcoming phonetic information continuously during prelexical speech processing.     

Delayed commitment in spoken word recognition: Evidence from cross-modal priming

Using the cross-modal priming paradigm, we attempted to determine whether semantic representations for word-final morphemes embedded in multisyllabic words (e.g., /lak/ in /hεmlak/) are independently activated in memory. That is, we attempted to determine whether the auditory prime, /hεmlak/, would facilitate lexical decision times to the visual target,key, even when the recognition point for/hεmlak / occurred prior to the end of the word, which should ensure deactivation of all lexical candidates. In the first experiment, a gating task was used in order to ensure that the multisyllabic words could be identified prior to their offsets. In the second experiment, lexical decision times for visually presented targets following spoken monosyllabic primes (e.g., /lak/-key) were compared with reaction times for the same visual targets following multisyllabic pairs (/hεmlak/-KEY). Significant priming was found for both the monosyllabic and the multisyllabic conditions. The results support a recognition strategy that initiates lexical access at strong syllables (Cutler & Norris, 1988) and operates according to a principle of delayed commitment (Marr, 1982).     

Syllabification strategies in spoken word processing: Evidence from phonological priming

Two experiments were conducted to examine which of two linguistic syllabification strategies, the maximal onset principle and the stress principle, is operative in auditory word recognition. Test stimuli consisted of bisyllabic words and nonwords containing two medial consonants, the second of which had a potential attachment to either the coda of the first syllable or the onset of the second syllable (e.g., MARKET). A phonological priming paradigm was used in which prime stimuli were artificially syllabified by inserting silence. In the critical conditions, the prime was consistent with the maximal onset principle (e.g., MAR-KET) or with the stress principle (e.g., MARK-ET). The results suggested that listeners prefer to attach a medial consonant to the onset of a syllable in a way that is characterized by the maximal onset principle. The results also indicate some use of the stress principle.     

Sentence context modifies compound word recognition: Evidence from eye movements

Two eye movement experiments are reported that examine the influence of sentence context on morphological processing. English compound words which vary in beginning lexeme frequency (Experiment 1) and ending lexeme frequency (Experiment 2) were embedded into sentence contexts that were either predictive of the compound word or were neutral with respect to the compound. A predictable sentence context reduced the effect of beginning lexeme frequency on first fixation and single fixation durations. However, sentence context did not modify effects of beginning and ending lexeme frequency in later fixation measures. These results further support the theoretical position that morphology plays a role at multiple levels within readers' mental lexicons. In addition, these results suggest that access to early morpho-orthographic processes can be influenced by sentence context, a finding that suggests an interactive relationship between sentence context and word recognition.