Cross-situational Statistical Learning Research Articles

The role of phonology in non-native word learning: Evidence from cross-situational statistical learning

Abstract Adults often encounter difficulty perceiving and processing sounds of a second language (L2). In order to acquire word-meaning mappings, learners need to determine what the language-relevant phonological contrasts are in the language. In this study, we examined the influence of phonology on non-native word learning, determining whether the language-relevant phonological contrasts could be acquired by abstracting over multiple experiences, and whether awareness of these contrasts could be related to learning. We trained English- and Mandarin-native speakers with pseudowords via a cross-situational statistical learning task (CSL). Learners were able to acquire the phonological contrasts across multiple situations, but similar-sounding words (i.e., minimal pairs) were harder to acquire, and words that contrast in a non-native suprasegmental feature (i.e., Mandarin lexical tone) were even harder for English-speakers, even with extended exposure. Furthermore, awareness of the non-native phonology was not found to relate to learning.

Parent implementation of a treatment for late talkers based on cross-situational statistical learning principles: Treatment fidelity and acceptability

Purpose Early intervention based on principles of cross-situational statistical learning (CSSL) for late-talking children has shown promise. This study explored whether parents could be trained to deliver this intervention protocol with fidelity and if they found the intervention to be acceptable. Method Mothers of four English-speaking children aged 18–30 months who scored <10th centile for expressive vocabulary were recruited to an 8-week group training program. Parents were taught principles of CSSL and asked to perform 16 home treatment sessions (30 minutes each) in total, providing auditory bombardment of target words in full sentences at high dose number and syntactic variability, using a range of physical exemplars. Home diaries and two videotaped sessions measured treatment fidelity. Pre- and post-treatment questionnaires measured acceptability. Result One parent discontinued the study after the second group training session. Three parents completed 15/16 group training sessions and reported completing 87% of home sessions. Two parents demonstrated implementing the intervention as per the target dose number by the first fidelity session (Weeks 2/3), and the third parent was very close to meeting target dose number by the second fidelity session (Weeks 7/8). Conclusion Parents can be trained to deliver an intervention based on cross-situational statistical learning principles.

The effect of lexicalization biases on cross-situational statistical learning of novel verbs

Abstract Languages vary in the mapping of relational terms onto events. For instance, English motion descriptions favor manner (how something moves) verbs over path (where something move) verbs, whereas those of other languages, like Spanish, show the opposite pattern. While these lexicalization biases are malleable, adopting a novel lexicalization pattern can be slow for second language learners. One potential mechanism for learning non-native verb mappings is cross-situational statistical learning (CSSL). However, the application of CSSL to verbs is limited and does not explicitly examine how lexicalization biases may complicate adults’ ability to resolve the referential uncertainty of multiple referents. We ask English-speaking monolingual adults to learn the mappings of ten verbs via CSSL. Verbs mapped onto either manner or path of motion, with the other event component held constant. Adults in both conditions demonstrated successful learning of novel verbs, with adults learning the manner verbs showing more consistent performance across accepting correct referents and rejecting incorrect ones. Our results are the first to demonstrate adults’ use of CSSL to acquire verb meanings that both align with and cut against native lexicalization biases and suggest a limited influence of lexicalization biases on adults’ learning in idealized CSSL conditions.

Constraints on novel word learning in heritage speakers.

Recent research on word learning has found that adults can rapidly learn novel words by tracking cross-situational statistics, but learning is greatly influenced by the phonological properties of the words and by the native language of the speakers. Mandarin-native speakers could easily pick up novel words with Mandarin tones after a short exposure, but English-native speakers had specific difficulty with the tonal components. It is, however, unclear how much experience with Mandarin is needed to successfully use the tonal cue in word learning. In this study, we explored this question by focusing on the heritage language population, who typically are exposed to the target language at an early age but then develop and switch to another majority language. Specifically, we investigated whether heritage Mandarin speakers residing in an English-speaking region and speaking English as a dominant language would be able to learn novel Mandarin tonal words from statistical tracking. It helps us understand whether early exposure to the target feature is sufficient to promote the use of that feature in word learning later in life. We trained 30 heritage Mandarin speakers with Mandarin pseudowords via a cross-situational statistical word learning task (CSWL). Heritage Mandarin speakers were able to learn the pseudowords across multiple situations, but similar-sounding words (i.e., minimal pairs) were more difficult to identify, and words that contrast only in lexical tones (i.e., Mandarin lexical tone) were distinguished at chance level throughout learning. We also collected information about the participants' heritage language (HL) experience and usage. We did not observe a relationship between HL experience/usage and performance in tonal word learning, suggesting that HL exposure does not necessarily lead to an advantage in learning the target language.

Reduced Implicit but not Explicit Knowledge of Cross-Situational Statistical Learning in Developmental Dyslexia.

Although statistical learning (SL) has been studied extensively in developmental dyslexia (DD), less attention has been paid to other fundamental challenges in language acquisition, such as cross-situational word learning. Such investigation is important for determining whether and how SL processes are affected in DD at the word level. In this study, typically developed (TD) adults and young adults with DD were exposed to a set of trials that contained multiple spoken words and multiple pictures of individual objects, with no information about word-referent correspondences provided within a trial. Nonetheless, cross-trial statistical relations could be exploited to learn word-referent mappings. The degree of within-trial reference uncertainty and the novelty of to-be-learned objects (novel or familiar) were varied under different learning conditions. The results show that across all conditions, young adults with DD were significantly impaired in their ability to exploit cross-trial regularities in co-occurring visual-auditory streams to discover word-referent mappings. Observed impairments were most pronounced when within-trial reference uncertainty was the highest. Subjective measures of knowledge awareness revealed greater development of implicit but not explicit knowledge in the TD group than in the DD group. Together, these findings suggest that the SL deficit in DD affects fundamental language learning challenges at the word level and points to greater reliance on explicit processes due to impaired implicit associative learning among individuals with DD. Such a deficit is likely to influence spoken language acquisition, and in turn affect literacy skills, in people with DD.

Replication of a single-case design cross-situational statistically based word learning treatment for late talking children

Purpose Late talking children are at risk of ongoing language impairment. This intervention study replicated and extended research based on cross-situational statistical learning principles. Method Three late talking children (age 24–32 months) were enrolled into the concurrent multiple baseline single-case experimental intervention study. The intervention consisted of 16 sessions over eight/nine weeks, including 10–11 pairs of target and control words (three per session). Children heard the target words a minimum of 64 times per session, in sentences with high linguistic variability in varied play activities. Result All children increased production of target words and expressive vocabulary, with statistically significant differences between word acquisition in baseline and intervention phases. One of the three children learnt statistically significantly more target words than control words. Conclusion The results replicated the findings of previous research for some but not all of the participants, providing individual evidence that this approach has promise as a therapy technique for late talking children.

Acquisition of novel word meaning via cross situational word learning: An event-related potential study

Cross-situational statistical word learning (CSWL) refers to the process whereby participants learn new words by tracking ambiguous word-object co-occurrences across time. This study used event-related potentials to explore the acquisition of novel word meanings via CSWL in healthy adults. After learning to associate novel auditory words (e.g., ‘ket’) with familiar objects (e.g., sword), participants performed a semantic judgement task where the learned novel words were paired with a familiar word belonging to either the same (e.g., dagger) or a different (e.g., harp) semantic category. As a comparison, the task also included word pairs comprising two familiar words. The analyses revealed that the unrelated novel word pairs elicited a similar N400 to that of the unrelated familiar word pairs, but with a different hemispheric distribution (left hemisphere for novel words, right hemisphere for familiar words). These findings demonstrate rapid meaning acquisition via CSWL, which is reflected at a neurophysiological level.

Subjective confidence influences word learning in a cross-situational statistical learning task

Learning is often accompanied by a subjective sense of confidence in one’s knowledge, a feeling of knowing what you know and how well you know it. Subjective confidence has been shown to guide learning in other domains, but has received little attention so far in the word learning literature. Across three word learning experiments, we investigated whether and how a sense of confidence in having acquired a word meaning influences the word learning process itself. First, we show evidence for a confirmation bias during word learning in a cross-situational statistical learning task: Learners who are highly confident they know the meaning of a word are more likely to persist in their belief than learners who are not, even after observing objective evidence disconfirming their belief. Second, we show that subjective confidence in a word meaning modulates inferential processes based on that word, affecting learning over the whole lexicon: Learners who hold high confidence in a word meaning are more likely to use that word to make mutual exclusivity inferences about the meaning of other words. We conclude that confidence influences word learning by modulating both information selection processes and inferential processes and discuss the implications of these results for word learning models.

Cross-situational statistical learning in children with developmental language disorder

ABSTRACT Children with Developmental Language Disorder (DLD) need more exposures to learn new words in an unambiguous context compared to children with typical development (TD). However, it remains unclear whether they would be able to learn new words by extracting frequencies over multiple word-object encounters in ambiguous situations. The present study examines this question through a cross-situational statistical-learning task (CSSL). Thirty-eight school-aged children with DLD and thirty-eight age/sex-matched TD children completed a CSSL eye-tracking experiment. Participants’ responses show that children with DLD had significantly poorer accuracy compared to TD children. However, both groups performed above chance. While the eye-tracking record evidenced no distinctive pattern between groups as children learnt new words, we observed a larger target visual preference in TD children when they were asked to find the referent for those new words. We discuss these findings in light of existing accounts for memory and language deficits in DLD.

A distributional perspective on the gavagai problem in early word learning

Word learning entails the mapping of an auditory word-form to its appropriate grammatical category (e.g., noun, verb, adjective), but before that mapping can occur, the naïve learner must infer which of the myriad of possible referents of that word was intended by the speaker. This creates a computational explosion of referential ambiguity referred to as the gavagai problem. In a set of corpus analyses of parent-directed speech to young infants, we describe the distributional information available to early word learners, with a focus on nouns and adjectives that refer to whole objects and object properties. And in two experiments on word-learning in adults spanning seven different distributional conditions, we document how variations in the ratio of novel labels for objects and properties affect the robustness of word learning. Our results suggest that the language input to 6- to 20-month-olds is robustly populated with high-frequency object words and high-frequency property words, but their co-occurrence is sparse. Although this distributional information slightly favors object words over property words, a more plausible account of the whole-object bias in early word learning is the inability to encode the details of an object/event during rapid naming. Our results from adults, presented with novel labels for multi-referent objects in a cross-situational statistical learning paradigm, also reveal this whole-object bias as well as the absence of property-label generalization to novel objects, even when the distribution of labels is shifted almost exclusively to property words. These results are discussed in terms of the relative ease of mapping auditory word-forms to whole objects vs. object properties, thereby limiting the combinatorics of the gavagai problem, especially in infants with immature encoding and memory representation abilities.

Learning vocabulary and grammar from cross-situational statistics

Across multiple situations, child and adult learners are sensitive to co-occurrences between individual words and their referents in the environment, which provide a means by which the ambiguity of word-world mappings may be resolved (Monaghan & Mattock, 2012; Scott & Fisher, 2012; Smith & Yu, 2008; Yu & Smith, 2007). In three studies, we tested whether cross-situational learning is sufficiently powerful to support simultaneous learning the referents for words from multiple grammatical categories, a more realistic reflection of more complex natural language learning situations. In Experiment 1, adult learners heard sentences comprising nouns, verbs, adjectives, and grammatical markers indicating subject and object roles, and viewed a dynamic scene to which the sentence referred. In Experiments 2 and 3, we further increased the uncertainty of the referents by presenting two scenes alongside each sentence. In all studies, we found that cross-situational statistical learning was sufficiently powerful to facilitate acquisition of both vocabulary and grammar from complex sentence-to-scene correspondences, simulating the situations that more closely resemble the challenge facing the language learner.

Successful Implicit Vocabulary Intervention for Three Cantonese-Speaking Toddlers: A Replicated Single-Case Design.

Purpose We report on a replicated single-case design study that measured the feasibility of an expressive vocabulary intervention for three Cantonese-speaking toddlers with small expressive lexicons relative to their age. The aim was to assess the cross-cultural and cross-linguistic feasibility of an intervention method developed for English-speaking children. Method A nonconcurrent multiple-baseline design was used with four baseline data points and 16 intervention sessions per participant. The intervention design incorporated implicit learning principles, high treatment dosage, and control of the phonological neighborhood density of the stimuli. The children (24-39 months) attended 7-9 weeks of twice weekly input-based treatment in which no explicit verbal production was required from the child. Each target word was provided as input a minimum of 64 times in at least two intervention sessions. Treatment feasibility was measured by comparison of how many of the target and control words the child produced across the intervention period, and parent-reported expressive vocabulary checklists were completed for comparison of pre- and postintervention child spoken vocabulary size. An omnibus effect size for the treatment effect of the number of target and control words produced across time was calculated using Kendall's Tau. Results There was a significant treatment effect for target words learned in intervention relative to baselines, and all children produced significantly more target than control words across the intervention period. The effect of phonological neighborhood density on expressive word production could not be evaluated because two of the three children learned all target words. Conclusion The results provide cross-cultural evidence of the feasibility of a model of intervention that incorporated a high-dosage, cross-situational statistical learning paradigm to teach spoken word production to children with small expressive lexicons.

Intentional Training With Speech Production Supports Children's Learning the Meanings of Foreign Words: A Comparison of Four Learning Tasks.

To determine the best techniques to teach children foreign words, we compared the effectiveness of four different learning tasks on their foreign-word learning (i.e., learning word forms and word meanings). The tasks included incidental learning, intentional learning with production, intentional learning without production, and cross-situational statistical learning. We also analyzed whether children’s age and cognitive skills correlate with the learning of word forms and word meanings. Forty-four 5–8-year-old children participated in the study. The results reveal that the children were able to learn the correct word forms from all four tasks and no differences emerged between the effectiveness of the tasks on the learning of word-forms. The children also learned the word meanings with all four tasks, yet the intentional task with production was more effective than the incidental task. This suggests that the ability of children to learn foreign words benefited from them knowing that they were supposed to learn new words and producing them aloud while training. The age of the children correlated with their learning results for word forms and meanings on the intentional task without production. The older children learned more effectively than the younger children in this task. Children’s phonological processing skills were correlated with learning the word meanings from the incidental task, suggesting that children with better phonological skills were able to benefit from incidental learning more than children with poorer phonological skills. Altogether, the results suggest that children’s foreign-language learning benefits from intentional training with speech production regardless of their age or cognitive skills.

Cross-situational statistical learning in younger and older adults

ABSTRACT Research investigating statistical learning, the process of tracking regularities in the environment, in older adults has been limited; with existing studies suggesting there are age-related declines. We aim to further understand older adults’ statistical learning abilities using a cross-situational statistical learning paradigm in which learners map novel words to novel objects. In Experiment 1, we manipulated task difficulty and found an overall age deficit but no interaction between age and difficulty. In Experiment 2, after extended practice with a first set of object-word mappings, learners could remap a subset of previously learned words to novel objects. Based on hyper-binding, older adults might be more willing to remap previously learned words to novel objects. However, despite overall poorer learning, older adults were actually less likely to remap. Even though older adults may have an associative memory deficit, learned associations are not more weakly bound for older relative to younger adults.

Cross-Situational Statistical Learning of New Words Despite Bilateral Hippocampal Damage and Severe Amnesia.

Word learning requires learners to bind together arbitrarily-related phonological, visual, and conceptual information. Prior work suggests that this binding can be robustly achieved via incidental cross-situational statistical exposure to words and referents. When cross-situational statistical learning (CSSL) is tested in the laboratory, there is no information on any given trial to identify the referent of a novel word. However, by tracking which objects co-occur with each word across trials, learners may acquire mappings through statistical association. While CSSL behavior is well-characterized, its brain correlates are not. The arbitrary nature of CSSL mappings suggests hippocampal involvement, but the incremental, statistical nature of the learning raises the possibility of neocortical or procedural learning systems. Prior studies have shown that neurological patients with hippocampal pathology have word-learning impairments, but this has not been tested in a statistical learning paradigm. Here, we used a neuropsychological approach to test whether patients with bilateral hippocampal pathology (N = 3) could learn new words in a CSSL paradigm. In the task, patients and healthy comparison participants completed a CSSL word-learning task in which they acquired eight word/object mappings. During each trial of the CSSL task, participants saw two objects on a computer display, heard one novel word, and selected the most likely referent. Across trials, words were 100% likely to co-occur with their referent, but only 14.3% likely with non-referents. Two of three amnesic patients learned the associations between objects and word forms, although performance was impaired relative to healthy comparison participants. Our findings show that the hippocampus is not strictly necessary for CSSL for words, although it may facilitate such learning. This is consistent with a hybrid account of CSSL supported by implicit and explicit memory systems, and may have translational applications for remediation of (word-) learning deficits in neurological populations with hippocampal pathology.

The influence of bilingualism on statistical word learning

Statistical learning is a fundamental component of language acquisition, yet to date, relatively few studies have examined whether these abilities differ in bilinguals. In the present study, we examine this issue by comparing English monolinguals with Chinese–English and English–Spanish bilinguals in a cross-situational statistical learning (CSSL) task. In Experiment 1, we assessed the ability of both monolinguals and bilinguals on a basic CSSL task that contained only one-to-one mappings. In Experiment 2, learners were asked to form both one-to-one and two-to-one mappings, and were tested at three points during familiarization. Overall, monolinguals and bilinguals did not differ in their learning of one-to-one mappings. However, bilinguals more quickly acquired two-to-one mappings, while also exhibiting greater proficiency than monolinguals. We conclude that the fundamental SL mechanism may not be affected by language experience, in accord with previous studies. However, when the input contains greater variability, bilinguals may be more prone to detecting the presence of multiple structures.

Cross-Situational Learning of Minimal Word Pairs.

Cross-situational statistical learning of words involves tracking co-occurrences of auditory words and objects across time to infer word-referent mappings. Previous research has demonstrated that learners can infer referents across sets of very phonologically distinct words (e.g., WUG, DAX), but it remains unknown whether learners can encode fine phonological differences during cross-situational statistical learning. This study examined learners' cross-situational statistical learning of minimal pairs that differed on one consonant segment (e.g., BON-TON), minimal pairs that differed on one vowel segment (e.g., DEET-DIT), and non-minimal pairs that differed on two or three segments (e.g., BON-DEET). Learners performed above chance for all pairs, but performed worse on vowel minimal pairs than on consonant minimal pairs or non-minimal pairs. These findings demonstrate that learners can encode fine phonetic detail while tracking word-referent co-occurrence probabilities, but they suggest that phonological encoding may be weaker for vowels than for consonants.

Cross-situational statistically based word learning intervention for late-talking toddlers

PurposeTo explore the efficacy of a word learning intervention for late-talking toddlers that is based on principles of cross-situational statistical learning. MethodsFour late-talking toddlers were individually provided with 7–10 weeks of bi-weekly word learning intervention that incorporated principles of cross-situational statistical learning. Treatment was input-based meaning that, aside from initial probes, children were not asked to produce any language during the sessions. Pre-intervention data included parent-reported measures of productive vocabulary and language samples. Data collected during intervention included production on probes, spontaneous production during treatment, and parent report of words used spontaneously at home. Data were analyzed for number of target words learned relative to control words, effect sizes, and pre–post treatment vocabulary measures. ResultsAll children learned more target words than control words and, on average, showed a large treatment effect size. Children made pre–post vocabulary gains, increasing their percentile scores on the MCDI, and demonstrated a rate of word learning that was faster than rates found in the literature. ConclusionsCross-situational statistically based word learning intervention has the potential to improve vocabulary learning in late-talking toddlers. Limitations on interpretation are also discussed.Learning outcomes: Readers will describe what cross-situational learning is and how it might apply to treatment. They will identify how including lexical and contextual variability in a word learning intervention for toddlers affected treatment outcomes. They will also recognize evidence of improved rate of vocabulary learning following treatment.

Context influences conscious appraisal of cross situational statistical learning.

Previous research in cross-situational statistical learning has established that people can track statistical information across streams in order to map nonce words to their referent objects (Yu and Smith, 2007). Under some circumstances, learners are able to acquire multiple mappings for a single object (e.g., Yurovsky and Yu, 2008). Here we explore whether having a contextual cue associated with a new mapping may facilitate this process, or the conscious awareness of learning. Using a cross-situational statistical learning paradigm, in which learners could form both 1:1 and 2:1 word–object mappings over two phases of learning, we collected confidence ratings during familiarization and provided a retrospective test to gage learning. In Condition 1, there were no contextual cues to indicate a change in mappings (baseline). Conditions 2 and 3 added contextual cues (a change in speaker voice or explicit instructions, respectively) to the second familiarization phase to determine their effects on the trajectory of learning. While contextual cues did not facilitate acquisition of 2:1 mappings as assessed by retrospective measures, confidence ratings for these mappings were significantly higher in contextual cue conditions compared to the baseline condition with no cues. These results suggest that contextual cues corresponding to changes in the input may influence the conscious awareness of learning.

Cross-situational statistical word learning in young children

Recent empirical work has highlighted the potential role of cross-situational statistical word learning in children’s early vocabulary development. In the current study, we tested 5- to 7-year-old children’s cross-situational learning by presenting children with a series of ambiguous naming events containing multiple words and multiple referents. Children rapidly learned word-to-object mappings by attending to the co-occurrence regularities across these ambiguous naming events. The current study begins to address the mechanisms underlying children’s learning by demonstrating that the diversity of learning contexts affects performance. The implications of the current findings for the role of cross-situational word learning at different points in development are discussed along with the methodological implications of employing school-aged children to test hypotheses regarding the mechanisms supporting early word learning.