Individual Differences in Language Acquisition and Processing

Introducing the Intra-Individual Variability Hypothesis in Explaining Individual Differences in Language Development

PURPOSE

Response times (RTs) are commonly used in studying language acquisition. However, previous research utilizing RT in the context of language has largely overlooked the intra-individual variability (IIV) of RTs, which could hold significant information about the processes underlying language acquisition.

METHOD

We explored the association between language abilities and RT variability in visuomotor tasks using two data sets from previously published studies. The participants were 7- to 10-year-old children (n = 77).

RESULTS

Our results suggest that increased variability in RTs is associated with weaker language abilities. Specifically, this within-participant variability in visuomotor RTs, especially the proportion of unusually slow responses, predicted language abilities better than mean RTs, a factor often linked to language skills in past research.

CONCLUSIONS

Based on our findings, we introduce the IIV hypothesis in explaining individual differences in language development. According to our hypothesis, inconsistency in the timing of cognitive processes, reflected by increased IIV in RTs, degrades learning different aspects of language, and results in individual differences in language abilities. Future studies should further examine the relationship between IIV and language abilities, and test the extent to which the possible relationship is causal.

The Emergence and Development of Palestinian Arabic Lexicon and Morphosyntax From 18 to 36 Months: A Communicative Development Inventory Study

PURPOSE

This study presents a comprehensive exploration of lexical and grammatical development in Palestinian Arabic (PA). The study aims to test the validity of the Palestinian Arabic Communicative Development Inventory (PA-CDI) as well as generate growth curves for lexical and morphosyntactic development, examine the order of emergence of both lexical and morphosyntactic categories, and explore the contribution of demographic and developmental factors to language development.

METHOD

Data were collected from 1,399 parents of PA children aged 18-36 months using an online PA-CDI.

RESULTS

The results show that as age increased, so did lexical and morphosyntactic production, along with considerable variability across individuals. While lexical development in PA resembles the order observed in other languages with nouns preceding verbs and adjectives, morphosyntactic development indicates early emergence of verbal inflectional morphology prior to noun pluralization or negation. Age of word combination and health problems are predictive of lexical and morphosyntactic development, and so are parental concerns.

CONCLUSIONS

Our findings indicate the potential of the PA-CDI as an assessment tool for lexical and morphosyntactic development among PA-speaking children in Israel. Our developmental growth curves may also be used to identify children at risk for developmental language disorder, particularly those falling below the 10th percentile, thus allowing for early identification and early intervention. The use of background variables, specifically parental concerns, health issues, and word combinations, along with the PA-CDI, could potentially enhance the precision of language delay assessment.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.26026777.

Pupillometry reveals resting state alpha power correlates with individual differences in adult auditory language comprehension

Although individual differences in adult language processing are well-documented, the neural basis of this variability remains largely unexplored. The current study addressed this gap in the literature by examining the relationship between resting state alpha activity and individual differences in auditory language comprehension. Alpha oscillations modulate cortical excitability, facilitating efficient information processing in the brain. While resting state alpha oscillations have been tied to individual differences in cognitive performance, their association with auditory language comprehension is less clear. Participants in the study were 80 healthy adults with a mean age of 25.8 years (SD = 7.2 years). Resting state alpha activity was acquired using electroencephalography while participants looked at a benign stimulus for 3 min. Participants then completed a language comprehension task that involved listening to 'syntactically simple' subject-relative clause sentences and 'syntactically complex' object-relative clause sentences. Pupillometry measured real-time processing demand changes, with larger pupil dilation indicating increased processing loads. Replicating past research, comprehending object relative clauses, compared to subject relative clauses, was associated with lower accuracy, slower reaction times, and larger pupil dilation. Resting state alpha power was found to be positively correlated with the pupillometry data. That is, participants with higher resting state alpha activity evidenced larger dilation during sentence comprehension. This effect was more pronounced for the 'complex' object sentences compared to the 'simple' subject sentences. These findings suggest the brain's capacity to generate a robust resting alpha rhythm contributes to variability in processing demands associated with auditory language comprehension, especially when faced with challenging syntactic structures. More generally, the study demonstrates that the intrinsic functional architecture of the brain likely influences individual differences in language comprehension.

The language network as a natural kind within the broader landscape of the human brain

Language behaviour is complex, but neuroscientific evidence disentangles it into distinct components supported by dedicated brain areas or networks. In this Review, we describe the 'core' language network, which includes left-hemisphere frontal and temporal areas, and show that it is strongly interconnected, independent of input and output modalities, causally important for language and language-selective. We discuss evidence that this language network plausibly stores language knowledge and supports core linguistic computations related to accessing words and constructions from memory and combining them to interpret (decode) or generate (encode) linguistic messages. We emphasize that the language network works closely with, but is distinct from, both lower-level - perceptual and motor - mechanisms and higher-level systems of knowledge and reasoning. The perceptual and motor mechanisms process linguistic signals, but, in contrast to the language network, are sensitive only to these signals' surface properties, not their meanings; the systems of knowledge and reasoning (such as the system that supports social reasoning) are sometimes engaged during language use but are not language-selective. This Review lays a foundation both for in-depth investigations of these different components of the language processing pipeline and for probing inter-component interactions.

SpEx: a German-language dataset of speech and executive function performance

This work presents data from 148 German native speakers (20-55 years of age), who completed several speaking tasks, ranging from formal tests such as word production tests to more ecologically valid spontaneous tasks that were designed to mimic natural speech. This speech data is supplemented by performance measures on several standardised, computer-based executive functioning (EF) tests covering domains of working-memory, cognitive flexibility, inhibition, and attention. The speech and EF data are further complemented by a rich collection of demographic data that documents education level, family status, and physical and psychological well-being. Additionally, the dataset includes information of the participants' hormone levels (cortisol, progesterone, oestradiol, and testosterone) at the time of testing. This dataset is thus a carefully curated, expansive collection of data that spans over different EF domains and includes both formal speaking tests as well as spontaneous speaking tasks, supplemented by valuable phenotypical information. This will thus provide the unique opportunity to perform a variety of analyses in the context of speech, EF, and inter-individual differences, and to our knowledge is the first of its kind in the German language. We refer to this dataset as SpEx since it combines speech and executive functioning data. Researchers interested in conducting exploratory or hypothesis-driven analyses in the field of individual differences in language and executive functioning, are encouraged to request access to this resource. Applicants will then be provided with an encrypted version of the data which can be downloaded.

A general exposome factor explains individual differences in functional brain network topography and cognition in youth

Childhood environments are critical in shaping cognitive neurodevelopment. With the increasing availability of large-scale neuroimaging datasets with deep phenotyping of childhood environments, we can now build upon prior studies that have considered relationships between one or a handful of environmental and neuroimaging features at a time. Here, we characterize the combined effects of hundreds of inter-connected and co-occurring features of a child's environment ("exposome") and investigate associations with each child's unique, multidimensional pattern of functional brain network organization ("functional topography") and cognition. We apply data-driven computational models to measure the exposome and define personalized functional brain networks in pre-registered analyses. Across matched discovery (n=5139, 48.5% female) and replication (n=5137, 47.1% female) samples from the Adolescent Brain Cognitive Development study, the exposome was associated with current (ages 9-10) and future (ages 11-12) cognition. Changes in the exposome were also associated with changes in cognition after accounting for baseline scores. Cross-validated ridge regressions revealed that the exposome is reflected in functional topography and can predict performance across cognitive domains. Importantly, a single measure capturing a child's exposome could more accurately and parsimoniously predict cognition than a wealth of personalized neuroimaging data, highlighting the importance of children's complex, multidimensional environments in cognitive neurodevelopment.

LexCHI: A quick lexical test for estimating language proficiency in Chinese

A prominent methodological issue in cognitive research on bilingualism is the lack of consistency in measuring second language (L2) proficiency. To reduce the inconsistency in L2 proficiency measurements, brief and valid vocabulary tests have been developed as an objective measure of proficiency in a variety of languages (e.g., English, French, Spanish). Here, we present LexCHI, a valid lexical test to measure Chinese proficiency. This freely available short test consists of 60 two-character items presented in simplified Chinese. Although it only takes a few minutes to complete LexCHI, the LexCHI scores in two studies correlated significantly with L2 participants' performance in a translation task and a cloze test. We believe that LexCHI is a useful tool for researchers who need to objectively measure Chinese proficiency as part of their investigations.

IDLaS-NL - A platform for running customized studies on individual differences in Dutch language skills via the Internet

We introduce the Individual Differences in Language Skills (IDLaS-NL) web platform, which enables users to run studies on individual differences in Dutch language skills via the Internet. IDLaS-NL consists of 35 behavioral tests, previously validated in participants aged between 18 and 30 years. The platform provides an intuitive graphical interface for users to select the tests they wish to include in their research, to divide these tests into different sessions and to determine their order. Moreover, for standardized administration the platform provides an application (an emulated browser) wherein the tests are run. Results can be retrieved by mouse click in the graphical interface and are provided as CSV file output via e-mail. Similarly, the graphical interface enables researchers to modify and delete their study configurations. IDLaS-NL is intended for researchers, clinicians, educators and in general anyone conducting fundamental research into language and general cognitive skills; it is not intended for diagnostic purposes. All platform services are free of charge. Here, we provide a description of its workings as well as instructions for using the platform. The IDLaS-NL platform can be accessed at www.mpi.nl/idlas-nl .

TANGO: A reliable, open-source, browser-based task to assess individual differences in gaze understanding in 3 to 5-year-old children and adults

Traditional measures of social cognition used in developmental research often lack satisfactory psychometric properties and are not designed to capture variation between individuals. Here, we present the TANGO (Task for Assessing iNdividual differences in Gaze understanding-Open); a brief (approx. 5-10min), reliable, open-source task to quantify individual differences in the understanding of gaze cues. Localizing the attentional focus of an agent is crucial in inferring their mental states, building common ground, and thus, supporting cooperation. Our interactive browser-based task works across devices and enables in-person and remote testing. The implemented spatial layout allows for discrete and continuous measures of participants' click imprecision and is easily adaptable to different study requirements. Our task measures inter-individual differences in a child (N = 387) and an adult (N = 236) sample. Our two study versions and data collection modes yield comparable results that show substantial developmental gains: the older children are, the more accurately they locate the target. High internal consistency and test-retest reliability estimates underline that the captured variation is systematic. Associations with social-environmental factors and language skills speak to the validity of the task. This work shows a promising way forward in studying individual differences in social cognition and will help us explore the structure and development of our core social-cognitive processes in greater detail.

Capturing individual differences in sentence processing: How reliable is the self-paced reading task?

Advances in research on language processing have originally come from group-level comparisons, but there is now a growing interest in individual differences. To investigate individual differences, tasks that have shown robust group-level differences are often used with the implicit assumption that they will also be reliable when used as an individual differences measure. Here, we examined whether one of the primary tasks used in psycholinguistic research on language processing, the self-paced reading task, can reliably measure individual differences in relative clause processing. We replicated the well-established effects of relative clauses at the group level, with object relative clauses being more difficult to process than subject relative clauses. However, when using difference scores, the reliability of the size of the relative clause effect was close to zero because the self-paced reading times for the different relative clause types were highly correlated within individuals. Nonetheless, we found that the self-paced reading task can be used to reliably capture individual differences in overall reading speed as well as key sentence regions when the two types of relative clause sentences are considered separately. Our results indicate that both the reliability and validity of different sentence regions need to be assessed to determine whether and when self-paced reading can be used to examine individual differences in language processing.

As easy as cake or a piece of pie? Processing idiom variation and the contribution of individual cognitive differences

Language users routinely use canonical, familiar idioms in everyday communication without difficulty. However, creativity in idiom use is more widespread than sometimes assumed, and little is known about how we process creative uses of idioms, and how individual differences in cognitive skills contribute to this. We used eye-tracking while reading and cross-modal priming to investigate the processing of idioms (e.g., play with fire) compared with creative variants (play with acid) and literal controls (play with toys), amongst a group of 47 university-level native speakers of English. We also conducted a series of tests to measure cognitive abilities (working memory capacity, inhibitory control, and processing speed). Eye-tracking results showed that in early reading behaviour, variants were read no differently to literal phrases or idioms but showed significantly longer overall reading times, with more rereading required compared with other conditions. Idiom variables (familiarity, decomposability, literal plausibility) and individual cognitive variables had limited effects throughout, although more decomposable phrases of all kinds required less overall reading time. Cross-modal priming-which has often shown a robust idiom advantage in past studies-demonstrated no difference between conditions, but decomposability again led to faster processing. Overall, results suggest that variants were treated more like literal phrases than novel metaphors, with subsequent effort required to make sense of these in the way that was consistent with the context provided.

Brain-phenotype predictions can survive across diverse real-world data

Recent work suggests that machine learning models predicting psychiatric treatment outcomes based on clinical data may fail when applied to unharmonized samples. Neuroimaging predictive models offer the opportunity to incorporate neurobiological information, which may be more robust to dataset shifts. Yet, among the minority of neuroimaging studies that undertake any form of external validation, there is a notable lack of attention to generalization across dataset-specific idiosyncrasies. Research settings, by design, remove the between-site variations that real-world and, eventually, clinical applications demand. Here, we rigorously test the ability of a range of predictive models to generalize across three diverse, unharmonized samples: the Philadelphia Neurodevelopmental Cohort (n=1291), the Healthy Brain Network (n=1110), and the Human Connectome Project in Development (n=428). These datasets have high inter-dataset heterogeneity, encompassing substantial variations in age distribution, sex, racial and ethnic minority representation, recruitment geography, clinical symptom burdens, fMRI tasks, sequences, and behavioral measures. We demonstrate that reproducible and generalizable brain-behavior associations can be realized across diverse dataset features with sample sizes in the hundreds. Results indicate the potential of functional connectivity-based predictive models to be robust despite substantial inter-dataset variability. Notably, for the HCPD and HBN datasets, the best predictions were not from training and testing in the same dataset (i.e., cross-validation) but across datasets. This result suggests that training on diverse data may improve prediction in specific cases. Overall, this work provides a critical foundation for future work evaluating the generalizability of neuroimaging predictive models in real-world scenarios and clinical settings.

Using Psychometric Network Analysis to Examine the Components of Spoken Word Recognition

Using language requires access to domain-specific linguistic representations, but also draws on domain-general cognitive skills. A key issue in current psycholinguistics is to situate linguistic processing in the network of human cognitive abilities. Here, we focused on spoken word recognition and used an individual differences approach to examine the links of scores in word recognition tasks with scores on tasks capturing effects of linguistic experience, general processing speed, working memory, and non-verbal reasoning. 281 young native speakers of Dutch completed an extensive test battery assessing these cognitive skills. We used psychometric network analysis to map out the direct links between the scores, that is, the unique variance between pairs of scores, controlling for variance shared with the other scores. The analysis revealed direct links between word recognition skills and processing speed. We discuss the implications of these results and the potential of psychometric network analysis for studying language processing and its embedding in the broader cognitive system.

Language Analytic Ability, Print Exposure, Memory and Comprehension of Complex Syntax by Adult Native Speakers

Nativist theories of language development assume that all native speakers of a particular language ultimately converge on (more or less) the same grammar, and argue that this is only possible because they are born with a genetic blueprint for language. However, a number of recent studies have found that there are, in fact, considerable individual differences in adult native speakers' grammatical attainment. In this study, we examine some possible reasons for these differences. We examine both learner internal cognitive factors (implicit and explicit memory for sequences, non-verbal working memory, and language analytic ability) as well as an experiential factor (print exposure). In contrast to many earlier studies which focused on the temporal aspects of language processing, we are interested in the extent to which individuals are able to use grammatical cues to extract meaning from complex sentences. To minimize the effect of performance factors, sentences remained on screen while participants responded to comprehension questions (thus easing working memory load) and participants were given as much time as they needed to respond. Our findings revealed large effects of language analytic ability and print exposure, and a much smaller effect of implicit learning. While the effect of implicit learning fits in well with current theories of language acquisition and processing, the first two findings do not. The strong relationship between print exposure and comprehension suggests that the ability to process complex syntax may depend on a particular type of language experience which is not available to all speakers. Finally, the effect of language analytic ability challenges the wide-held conviction that the ability to identify and explicitly reason about linguistic patterns is only relevant in adult second language learning.

The neural mechanisms underlying the processing of consonant, vowel and tone during Chinese typing: an fNIRS study

Many studies have explored the role of consonant, vowel, and tone in Chinese word identification or sentence comprehension. However, few studies have explored their roles and neural basis during Chinese word production, especially when involving neural basis. The present fNIRS study investigated the neural mechanisms of consonant, vowel, and tone processing during Chinese typing. Participants were asked to name the Chinese characters displayed on a computer screen by typing on a keyboard while hearing a simultaneously presented auditory stimulus. The auditory stimulus was either consistent with the characters' pronunciation (consistent condition) or mismatched in the consonant, vowel, or tone of the character pronunciation. The fNIRS results showed that compared with the consistent condition (as baseline), the consonant mismatch condition evoked lower levels of oxygenated hemoglobin (HbO) activation in the left inferior frontal gyrus Broca's triangle and left superior temporal gyrus. Vowel mismatch condition evoked a higher level of HbO activation in the top of the left inferior frontal gyrus and left middle frontal gyrus. The regions and patterns of brain activation evoked by tone mismatch were the same as those of vowel mismatch. The study indicated that consonant, vowel and tone all play a role in Chinese character production. The sensitive brain areas were all in the left hemisphere. However, the neural mechanism of consonant processing differed from vowel processing in both brain regions and patterns, while tone and vowel processing shared the same regions.

An individual differences perspective on pragmatic abilities in the preschool years

Pragmatic abilities are fundamental to successful language use and learning. Individual differences studies contribute to understanding the psychological processes involved in pragmatic reasoning. Small sample sizes, insufficient measurement tools, and a lack of theoretical precision have hindered progress, however. Three studies addressed these challenges in three- to 5-year-old German-speaking children (N = 228, 121 female). Studies 1 and 2 assessed the psychometric properties of six pragmatics tasks. Study 3 investigated relations among pragmatics tasks and between pragmatics and other cognitive abilities. The tasks were found to measure stable variation between individuals. Via a computational cognitive model, individual differences were traced back to a latent pragmatics construct. This presents the basis for understanding the relations between pragmatics and other cognitive abilities. RESEARCH HIGHLIGHTS: Individual differences in pragmatic abilities are important to understanding variation in language development. Research in this domain lacks a precise theoretical framework and psychometrically high-quality measures. We present six tasks capturing a wide range of pragmatic abilities with excellent re-test reliability. We use a computational cognitive model to provide a substantive theory of individual differences in pragmatic abilities.

The State of Cognitive Control in Language Processing

Understanding language requires readers and listeners to cull meaning from fast-unfolding messages that often contain conflicting cues pointing to incompatible ways of interpreting the input (e.g., "The cat was chased by the mouse"). This article reviews mounting evidence from multiple methods demonstrating that cognitive control plays an essential role in resolving conflict during language comprehension. How does cognitive control accomplish this task? Psycholinguistic proposals have conspicuously failed to address this question. We introduce an account in which cognitive control aids language processing when cues conflict by sending top-down biasing signals that strengthen the interpretation supported by the most reliable evidence available. We also provide a computationally plausible model that solves the critical problem of how cognitive control "knows" which way to direct its biasing signal by allowing linguistic knowledge itself to issue crucial guidance. Such a mental architecture can explain a range of experimental findings, including how moment-to-moment shifts in cognitive-control state-its level of activity within a person-directly impact how quickly and successfully language comprehension is achieved.

Effects of individual differences in text exposure on sentence comprehension

Linguistic experience plays a clear role in accounting for variability in sentence comprehension behavior across individuals and across sentence types. We aimed to understand how individual differences in reading experience predict reading behavior. Corpus analyses revealed the frequencies with which our experimental items appeared in written and spoken language. We hypothesized that reading experience should affect sentence comprehension most substantially for sentence types that individuals primarily encounter through written language. Readers with more text exposure were faster and more accurate readers overall, but they read sentence types biased to written language particularly faster than did readers with less text exposure. We see clear effects of text exposure on sentence comprehension in ways that allow explicit links between written and spoken corpus statistics and behavior. We discuss theoretical implications of effects of text exposure for experience-based approaches to sentence processing.

Neural underpinnings of processing combinatorial unstated meaning and the influence of individual cognitive style

We investigated the neurocognitive mechanisms underlying the processing of combinatorial unstated meaning. Sentences like "Charles jumped for 5 minutes." engender an iterative meaning that is not explicitly stated but enriched by comprehenders beyond simple composition. Comprehending unstated meaning involves meaning contextualization-integrative meaning search in sentential-discourse context. Meanwhile, people differ in how they process information with varying context sensitivity. We hypothesized that unstated meaning processing would vary with individual socio-cognitive propensity indexed by the Autism-Spectrum Quotient (AQ), accompanied by differential cortical engagements. Using functional magnetic resonance imaging, we examined the processing of sentences with unstated iterative meaning in typically-developed individuals and found an engagement of the fronto-parietal network, including the left pars triangularis (L.PT), right intraparietal (R.IPS), and parieto-occipital sulcus (R.POS). We suggest that the L.PT subserves a contextual meaning search, while the R.IPS/POS supports enriching unstated iteration in consideration of event durations and interval lengths. Moreover, the activation level of these regions negatively correlated with AQ. Higher AQ ties to lower L.PT activation, likely reflecting weaker context sensitivity, along with lower IPS activation, likely reflecting weaker computation of events' numerical-temporal specifications. These suggest that the L.PT and R.IPS/POS support the processing of combinatorial unstated meaning, with the activation level modulated by individual cognitive styles.

Studying Individual Differences in Language Comprehension: The Challenges of Item-Level Variability and Well-Matched Control Conditions

Translating experimental tasks that were designed to investigate differences between conditions at the group-level into valid and reliable instruments to measure individual differences in cognitive skills is challenging (Hedge et al., 2018; Rouder et al., 2019; Rouder & Haaf, 2019). For psycholinguists, the additional complexities associated with selecting or constructing language stimuli, and the need for appropriate well-matched baseline conditions make this endeavour particularly complex. In a typical experiment, a process-of-interest (e.g. ambiguity resolution) is targeted by contrasting performance in an experimental condition with performance in a well-matched control condition. In many cases, careful between-condition matching precludes the same participant from encountering all stimulus items. Unfortunately, solutions that work for group-level research (e.g. constructing counterbalanced experiment versions) are inappropriate for individual-differences designs. As a case study, we report an ambiguity resolution experiment that illustrates the steps that researchers can take to address this issue and assess whether their measurement instrument is both valid and reliable. On the basis of our findings, we caution against the widespread approach of using datasets from group-level studies to also answer important questions about individual differences.

Developmental changes in the categorization of speech and song

Music and language are two fundamental forms of human communication. Many studies examine the development of music- and language-specific knowledge, but few studies compare how listeners know they are listening to music or language. Although we readily differentiate these domains, how we distinguish music and language-and especially speech and song- is not obvious. In two studies, we asked how listeners categorize speech and song. Study 1 used online survey data to illustrate that 4- to 17-year-olds and adults have verbalizable distinctions for speech and song. At all ages, listeners described speech and song differences based on acoustic features, but compared with older children, 4- to 7-year-olds more often used volume to describe differences, suggesting that they are still learning to identify the features most useful for differentiating speech from song. Study 2 used a perceptual categorization task to demonstrate that 4-8-year-olds and adults readily categorize speech and song, but this ability improves with age especially for identifying song. Despite generally rating song as more speech-like, 4- and 6-year-olds rated ambiguous speech-song stimuli as more song-like than 8-year-olds and adults. Four acoustic features predicted song ratings: F0 instability, utterance duration, harmonicity, and spectral flux. However, 4- and 6-year-olds' song ratings were better predicted by F0 instability than by harmonicity and utterance duration. These studies characterize how children develop conceptual and perceptual understandings of speech and song and suggest that children under age 8 are still learning what features are important for categorizing utterances as speech or song. RESEARCH HIGHLIGHTS: Children and adults conceptually and perceptually categorize speech and song from age 4. Listeners use F0 instability, harmonicity, spectral flux, and utterance duration to determine whether vocal stimuli sound like song. Acoustic cue weighting changes with age, becoming adult-like at age 8 for perceptual categorization and at age 12 for conceptual differentiation. Young children are still learning to categorize speech and song, which leaves open the possibility that music- and language-specific skills are not so domain-specific.

Multivariate fMRI responses in superior temporal cortex predict visual contributions to, and individual differences in, the intelligibility of noisy speech

Humans have the unique ability to decode the rapid stream of language elements that constitute speech, even when it is contaminated by noise. Two reliable observations about noisy speech perception are that seeing the face of the talker improves intelligibility and the existence of individual differences in the ability to perceive noisy speech. We introduce a multivariate BOLD fMRI measure that explains both observations. In two independent fMRI studies, clear and noisy speech was presented in visual, auditory and audiovisual formats to thirty-seven participants who rated intelligibility. An event-related design was used to sort noisy speech trials by their intelligibility. Individual-differences multidimensional scaling was applied to fMRI response patterns in superior temporal cortex and the dissimilarity between responses to clear speech and noisy (but intelligible) speech was measured. Neural dissimilarity was less for audiovisual speech than auditory-only speech, corresponding to the greater intelligibility of noisy audiovisual speech. Dissimilarity was less in participants with better noisy speech perception, corresponding to individual differences. These relationships held for both single word and entire sentence stimuli, suggesting that they were driven by intelligibility rather than the specific stimuli tested. A neural measure of perceptual intelligibility may aid in the development of strategies for helping those with impaired speech perception.

The association between statistical learning and language development during childhood: A scoping review

The statistical account of language acquisition asserts that language is learned through computations on the statistical regularities present in natural languages. This type of account can predict variability in language development measures as arising from individual differences in extracting this statistical information. Given that statistical learning has been attested across different domains and modalities, a central question is which modality is more tightly yoked with language skills. The results of a scoping review, which aimed for the first time at identifying the evidence of the association between statistical learning skills and language outcomes in typically developing infants and children, provide preliminary support for the statistical learning account of language acquisition, mostly in the domain of lexical outcomes, indicating that typically developing infants and children with stronger auditory and audio-visual statistical learning skills perform better on lexical competence tasks. The results also suggest that the relevance of statistical learning skills for language development is dependent on sensory modality.

Individual Differences in Bilingual Child Language Acquisition: A plunge into a Complex and Dynamic Network

Large individual differences in language skills are well documented in monolingual children (e.g., Kidd, Donnelly & Christiansen, 2018). In bilinguals, the broad variation is even more pronounced. Interestingly, some bilingual children might be weak in their Heritage Language (HL, also labeled as Minority Language, Home Language, Community Language), to which they have naturalistic exposure from birth. Others might be weak in their Societal Language (SL), the language of the surrounding and educational environment. Large individual differences are observed in neurotypical bilingually exposed children as well as in their bilingually raised peers with developmental language disorder, autism spectrum disorder, and hearing impairment (see also Armon-Lotem & Meir, 2016; Meir & Novogrodsky, 2020). Figure 1 visualizes individual differences in morphosyntactic skills of monolingual and bilingual children with typical language development aged 5;5-6;8 as indexed by the LITMUS Sentence Repetition tasks (the data are drawn from Armon-Lotem & Meir, 2016; Meir, 2018). While monolingual preschool children (MonoRU and MonoHE) show little variation, bilinguals with different levels of dominance (balanced bilinguals: BB; HL dominant: HL-D; SL dominant: SL-D) as determined by standardized tests exhibit large individual differences within each language and across their two languages.

Individual Differences in Holistic and Compositional Language Processing

Individual differences in cognitive abilities are ubiquitous across the spectrum of proficient language users. Although speakers differ with regard to their memory capacity, ability for inhibiting distraction, and ability to shift between different processing levels, comprehension is generally successful. However, this does not mean it is identical across individuals; listeners and readers may rely on different processing strategies to exploit distributional information in the service of efficient understanding. In the following psycholinguistic reading experiment, we investigate potential sources of individual differences in the processing of co-occurring words. Participants read modifier-noun bigrams like absolute silence in a self-paced reading task. Backward transition probability (BTP) between the two lexemes was used to quantify the prominence of the bigram as a whole in comparison to the frequency of its parts. Of five individual difference measures (processing speed, verbal working memory, cognitive inhibition, global-local scope shifting, and personality), two proved to be significantly associated with the effect of BTP on reading times. Participants who could inhibit a distracting global environment in order to more efficiently retrieve a single part and those that preferred the local level in the shifting task showed greater effects of the co-occurrence probability of the parts. We conclude that some participants are more likely to retrieve bigrams via their parts and their co-occurrence statistics whereas others more readily retrieve the two words together as a single chunked unit.

The role of prosody in interpreting causality in English discourse

Previous studies have well established that certain causal connectives encode information about the semantic-pragmatic distinction between different types of causal relations such as CAUSE-CONSEQUENCE versus CLAIM-ARGUMENT relations. These "specialized" causal connectives assist listeners in discerning different types of causality. Additionally, research has demonstrated that utterances expressing CLAIM-ARGUMENT relations exhibit distinct prosodic characteristics compared to utterances expressing CAUSE-CONSEQUENCE relations. However, it remains unknown whether the prosodic characteristics of utterances expressing causality can aid listeners in determining the specific type of causality being conveyed. To address this knowledge gap, this study investigates the impact of the prosody, specifically the prosody of the causal connective so in English, on listeners' interpretation of the type of causality expressed. We conducted a perception experiment employing a forced-choice discourse completion task, where the participants were required to select a continuation for each sound clip they heard. The sound clip consisted of factual events followed by the causal connective so. We found that the odds of listeners choosing subjective continuations over objective continuations increased when the connective so at the end of the sound clip was pronounced with subjective causality prosodic features, such as prolonged duration and a concave f0 contour. This finding suggests that the prosody of the connective so plays a role in conveying subjectivity in causality, guiding listeners in interpreting causal relations. In addition, it is important to note that our data revealed individual variation among listeners in their interpretations of prosodic information related to subjective-objective causality contrast.

The (Co)Evolution of Language and Music Under Human Self-Domestication

Together with language, music is perhaps the most distinctive behavioral trait of the human species. Different hypotheses have been proposed to explain why only humans perform music and how this ability might have evolved in our species. In this paper, we advance a new model of music evolution that builds on the self-domestication view of human evolution, according to which the human phenotype is, at least in part, the outcome of a process similar to domestication in other mammals, triggered by the reduction in reactive aggression responses to environmental changes. We specifically argue that self-domestication can account for some of the cognitive changes, and particularly for the behaviors conducive to the complexification of music through a cultural mechanism. We hypothesize four stages in the evolution of music under self-domestication forces: (1) collective protomusic; (2) private, timbre-oriented music; (3) small-group, pitch-oriented music; and (4) collective, tonally organized music. This line of development encompasses the worldwide diversity of music types and genres and parallels what has been hypothesized for languages. Overall, music diversity might have emerged in a gradual fashion under the effects of the enhanced cultural niche construction as shaped by the progressive decrease in reactive (i.e., impulsive, triggered by fear or anger) aggression and the increase in proactive (i.e., premeditated, goal-directed) aggression.

How essentialist reasoning about language acquisition relates to educational myths and policy endorsements

How people conceptualize learning is related to real-world educational consequences across many domains of education. Despite its centrality to the educational system, we know little about how the public reasons about language acquisition, and the potential consequences for their thinking about real-world issues (e.g., policy endorsements). The current studies examined people's essentialist beliefs about language acquisition (e.g., that language is innate and biologically based), then investigated how individual differences in these beliefs related to the endorsement of educational myths and policies. We probed several dimensions of essentialist beliefs, including that language acquisition is innate, genetically based, and wired in the brain. In two studies, we tested specific hypotheses regarding the extent to which people use essentialist thinking when reasoning about: learning a specific language (e.g., Korean), learning a first language more generally, and learning two or more languages. Across studies, participants were more likely to essentialize the ability to learn multiple languages than one's first language, and more likely to essentialize the learning of multiple languages and one's first language than the learning of a particular language. We also found substantial individual differences in the degree to which participants essentialized language acquisition. In both studies, these individual differences correlated with an endorsement of language-related educational neuromyths (Study 1 and pre-registered Study 2), and rejection of educational policies that promote multilingual education (Study 2). Together, these studies reveal the complexity of how people reason about language acquisition and its corresponding educational consequences.

From One Bilingual to the Next: An Iterated Learning Study on Language Evolution in Bilingual Societies

Studies of language evolution in the lab have used the iterated learning paradigm to show how linguistic structure emerges through cultural transmission-repeated cycles of learning and use across generations of speakers . However, agent-based simulations suggest that prior biases crucially impact the outcome of cultural transmission. Here, we explored this notion through an iterated learning study of English-French bilingual adults (mostly sequential bilinguals dominant in English). Each participant learned two unstructured artificial languages in a counterbalanced fashion, one resembling English, another resembling French at the phono-orthographic level. The output of each participant was passed down to the next participant, forming diffusion chains of 10 generations per language. We hypothesized that artificial languages would become easier to learn and exhibit greater structure when they were aligned with participants' bilingual experience (i.e., English languages being easier to learn overall), or as a function of practice (i.e., languages learned second being easier to learn overall). Instead, we found that English-like languages became more structured over generations, but only when they were learned first. In contrast, French-like languages became more structured regardless of the order of learning, suggesting the presence of an asymmetric switch cost during artificial language learning. Moreover, individual differences in language usage modulated the amount of structure produced by the participants. Overall, these data suggest that bilingual experience impacts how novel languages are learned at an individual level, which can then scale up to cultural transmission of novel language at a group level.

Implicit Perception of Differences between NLP-Produced and Human-Produced Language in the Mentalizing Network

Natural language processing (NLP) is central to the communication with machines and among ourselves, and NLP research field has long sought to produce human-quality language. Identification of informative criteria for measuring NLP-produced language quality will support development of ever-better NLP tools. The authors hypothesize that mentalizing network neural activity may be used to distinguish NLP-produced language from human-produced language, even for cases where human judges cannot subjectively distinguish the language source. Using the social chatbots Google Meena in English and Microsoft XiaoIce in Chinese to generate NLP-produced language, behavioral tests which reveal that variance of personality perceived from chatbot chats is larger than for human chats are conducted, suggesting that chatbot language usage patterns are not stable. Using an identity rating task with functional magnetic resonance imaging, neuroimaging analyses which reveal distinct patterns of brain activity in the mentalizing network including the DMPFC and rTPJ in response to chatbot versus human chats that cannot be distinguished subjectively are conducted. This study illustrates a promising empirical basis for measuring the quality of NLP-produced language: adding a judge's implicit perception as an additional criterion.

Does age moderate the influence of early life language experiences? A Naturalistic home observation study

We explored if children's age moderated associations between their early life language experiences and their linguistic and cognitive skills. For 107 British children, aged 24 to 48 months, and their families, we collected 3 day-long audio-recordings of their naturalistic home environments (M = 15.06 h per day, SD = 1.87). Children's cognitive ability was assessed by parent-ratings and with a cognitive testing booklet that children completed at home. We found that the quantity, lexical diversity and vocabulary sophistication of adult speech were associated with children's linguistic and cognitive skills. However, these associations were not moderated by children's age. Our findings suggest that the influence of early life language experience is not differentiated at age 24 to 48 months, at least in the current sample.

The influences of working memory updating on word association effects and thematic role assignment during sentence processing

The current study investigated how individual variability in working memory (WM) updating affects real-time processing of thematic role assignment and word association during sentence reading comprehension when ERPs were recorded. By adopting a factorial design, four types of sentences were formed by crossing word association and role assignment as independent variables. The results indicated that associated words evoked a smaller N400 effect but a larger P600 effect than unassociated words in the high WM group, whereas no word association effect was found in the low WM group. In contrast, role reversal elicited larger N400 effects for both groups. These results suggest that individual differences in WM updating influenced whether and how readers retrieved and integrated the associated word in whole sentences but did not influence the online assignment of thematic roles during sentence reading. Individuals with high WM updating, in contrast to those with low WM updating, were good at making use of word-associated information provided by the preceding context in current processing.

Cross-Cultural Sex/Gender Differences in Produced Word Content Before the Age of 3 Years

Does sex/gender matter for language acquisition? Small advantages in vocabulary size for females are well documented. In this study, however, we found that children's early vocabulary composition was a significantly better predictor of sex/gender than their vocabulary size. We conducted classification analysis on word-production data from children (12-36 months old, n = 39,553) acquiring 26 different languages. Children's sex/gender was classified at above-chance levels in 22 of 26 languages. Classification accuracy was significantly higher than for models based on vocabulary size and increased as a function of sample size. Boys produced more words for vehicles and outdoor scenes, whereas girls produced more words for clothing and body parts. Classification accuracy also increased as a function of age and peaked at 30 months, reaching accuracy levels observed in studies of adult word use. These differences in vocabulary are indicative of differences in the lifeworld of children and may themselves cause further differences in development.

From Puzzle to Progress: How Engaging With Neurodiversity Can Improve Cognitive Science

In cognitive science, there is a tacit norm that phenomena such as cultural variation or synaesthesia are worthy examples of cognitive diversity that contribute to a better understanding of cognition, but that other forms of cognitive diversity (e.g., autism, attention deficit hyperactivity disorder/ADHD, and dyslexia) are primarily interesting only as examples of deficit, dysfunction, or impairment. This status quo is dehumanizing and holds back much-needed research. In contrast, the neurodiversity paradigm argues that such experiences are not necessarily deficits but rather are natural reflections of biodiversity. Here, we propose that neurodiversity is an important topic for future research in cognitive science. We discuss why cognitive science has thus far failed to engage with neurodiversity, why this gap presents both ethical and scientific challenges for the field, and, crucially, why cognitive science will produce better theories of human cognition if the field engages with neurodiversity in the same way that it values other forms of cognitive diversity. Doing so will not only empower marginalized researchers but will also present an opportunity for cognitive science to benefit from the unique contributions of neurodivergent researchers and communities.

The influence of oral vocabulary knowledge on individual differences in a computational model of reading

Studies have demonstrated systematic individual differences in the degree of semantic reliance (SR) when reading aloud exception words in adult skilled readers. However, the origins of individual differences in reading remain unclear. Using a connectionist model of reading, this study investigated whether oral vocabulary knowledge may affect the degree of SR as a potential source of individual differences in reading. Variety in oral vocabulary knowledge was simulated by training the model to learn the mappings between spoken and meaning word forms with different vocabulary sizes and quantities of exposure to these vocabularies. The model's SR in the reading aloud task was computed. The result demonstrated that the model with varying amounts of oral exposure and vocabulary sizes had different levels of SR. Critically, SR was able to predict the performance of the model on reading aloud and nonword reading, which assimilated behavioural reading patterns. Further analysis revealed that SR was largely associated with the interaction between oral vocabulary exposure and oral vocabulary size. When the amount of exposure was limited, SR significantly increased with vocabulary sizes but decreased then with vocabulary sizes. Overall, the simulation results provide the first computational evidence of the direct link between oral vocabulary knowledge and the degree of SR as a source of individual differences in reading.

Uncovering the Structure of Semantic Representations Using a Computational Model of Decision-Making

According to logical theories of meaning, a meaning of an expression can be formalized and encoded in truth conditions. Vagueness of the language and individual differences between people are a challenge to incorporate into the meaning representations. In this paper, we propose a new approach to study truth-conditional representations of vague concepts. For a case study, we selected two natural language quantifiers most and more than half. We conducted two online experiments, each with 90 native English speakers. In the first experiment, we tested between-subjects variability in meaning representations. In the second experiment, we tested the stability of meaning representations over time by testing the same group of participants in two experimental sessions. In both experiments, participants performed the verification task. They verified a sentence with a quantifier (e.g., "Most of the gleerbs are feezda.") based on the numerical information provided in the second sentence, (e.g., "60% of the gleerbs are feezda"). To investigate between-subject and within-subject differences in meaning representations, we proposed an extended version of the Diffusion Decision Model with two parameters capturing truth conditions and vagueness. We fit the model to responses and reaction times data. In the first experiment, we found substantial between-subject differences in representations of most as reflected by the variability in the truth conditions. Moreover, we found that the verification of most is proportion-dependent as reflected in the reaction time effect and model parameter. In the second experiment, we showed that quantifier representations are stable over time as reflected in stable model parameters across two experimental sessions. These findings challenge semantic theories that assume the truth-conditional equivalence of most and more than half and contribute to the representational theory of vague concepts. The current study presents a promising approach to study semantic representations, which can have a wide application in experimental linguistics.

Literacy-related differences in morphological knowledge: A nonce-word study

Using a nonce-word inflection task, we examine the morphosyntactic productivity of adult native speakers of Spanish who are either beginning to learn to read and write (semi-literates) or have acquired literacy in late adulthood (late-literates), as well as age-matched controls (high-literates). High-literates consistently provided the appropriate form more often than late-literates, who in turn were better than semi-literate participants. Crucially, group interacted with person, number, and conjugation, such that the between-group differences were larger for the less frequent cells in the paradigm, indicating that literacy-related differences are not merely a consequence of the high-literacy group being more engaged or test-wise. This suggests that the availability of written representations may facilitate the acquisition of certain aspects of grammar. We also observed vast individual differences in productivity with inflectional endings. These results add to the growing body of research which challenges the assumption that all native speakers converge on the same grammar early in development.

Measuring Spatial Perspective Taking: Analysis of Four Measures Using Item Response Theory

Research on spatial thinking requires reliable and valid measures of individual differences in various component skills. Spatial perspective taking (PT)-the ability to represent viewpoints different from one's own-is one kind of spatial skill that is especially relevant to navigation. This study had two goals. First, the psychometric properties of four PT tests were examined: Four Mountains Task (FMT), Spatial Orientation Task (SOT), Perspective-Taking Task for Adults (PTT-A), and Photographic Perspective-Taking Task (PPTT). Using item response theory (IRT), item difficulty, discriminability, and efficiency of item information functions were evaluated. Second, the relation of PT scores to general intelligence, working memory, and mental rotation (MR) was assessed. All tasks showed good construct validity except for FMT. PPTT tapped a wide range of PT ability, with maximum measurement precision at average ability. PTT-A captured a lower range of ability. Although SOT contributed less measurement information than other tasks, it did well across a wide range of PT ability. After controlling for general intelligence and working memory, original and IRT-refined versions of PT tasks were each related to MR. PTT-A and PPTT showed relatively more divergent validity from MR than SOT. Tests of dimensionality indicated that PT tasks share one common PT dimension, with secondary task-specific factors also impacting the measurement of individual differences in performance. Advantages and disadvantages of a hybrid PT test that includes a combination of items across tasks are discussed.

Building a Cognitive Science of Human Variation: Individual Differences in Spatial Navigation

The aim of this issue is to take stock of cognitive science of human variation in the field of spatial navigation, an important domain in which debates have often assumed an invariant human mind. Addressing the challenge of individual differences requires cognitive scientists to change their practices in several ways. First, we need to consider how to design measures and paradigms that have adequate psychometric characteristics. Second, using reliable, efficient, and valid measures, we need to examine how people vary from time to time, both in the short run due to emotions, such as stress or time pressure, and in the longer run, due to training or living in physical environments that require wayfinding skills. Third, we need to study people different from the traditional college participants, including variations in age, gender, education, culture, physical environment, and possible interactions among these variables.

Long-term memory predictors of adult language learning at the interface between syntactic form and meaning

Recent neurocognitive models of second language learning have posited specific roles for declarative and procedural memory in the processing of novel linguistic stimuli. Pursuing this line of investigation, the present exploratory study examined the role of declarative and procedural memory abilities in the early stages of adult comprehension of sentences in a miniature language with natural language characteristics (BrocantoJ). Thirty-six native Italian young adults were aurally exposed to BrocantoJ in the context of a computer game over three sessions on consecutive days. Following vocabulary training and passive exposure, participants were asked to perform game moves described by aural sentences in the language. Game trials differed with respect to the information the visual context offered. In part of the trials processing of relationships between grammatical properties of the language (word order and morphological case marking) and noun semantics (thematic role) was necessary in order reach an accurate outcome, whereas in others nongrammatical contextual cues were sufficient. Declarative and procedural learning abilities were respectively indexed by visual and verbal declarative memory measures and by a measure of visual implicit sequence learning. Overall, the results indicated a substantial role of declarative learning ability in the early stages of sentence comprehension, thus confirming theoretical predictions and the findings of previous similar studies in miniature artificial language paradigms. However, for trials that specifically probed the learning of relationships between morphosyntax and semantics, a positive interaction between declarative and procedural learning ability also emerged, indicating the cooperative engagement of both types of learning abilities in the processing of relationships between ruled-based grammar and interpretation in the early stages of exposure to a new language in adults.

No statistical learning advantage in children over adults: Evidence from behaviour and neural entrainment

Explicit recognition measures of statistical learning (SL) suggest that children and adults have similar linguistic SL abilities. However, explicit tasks recruit additional cognitive processes that are not directly relevant for SL and may thus underestimate children's true SL capacities. In contrast, implicit tasks and neural measures of SL should be less influenced by explicit, higher-level cognitive abilities and thus may be better suited to capturing developmental differences in SL. Here, we assessed SL to six minutes of an artificial language in English-speaking children (n = 56, 24 females, M = 9.98 years) and adults (n = 44; 31 females, M = 22.97 years), using explicit and implicit behavioural measures and an EEG measure of neural entrainment. With few exceptions, children and adults showed largely similar performance on the behavioural explicit and implicit tasks, replicating prior work. Children and adults also demonstrated robust neural entrainment to both words and syllables, with a similar time course of word-level entrainment, reflecting learning of the hidden word structure. These results demonstrate that children and adults have similar linguistic SL abilities, even when learning is assessed through implicit performance-based and neural measures.

Constraints on infants' ability to extract non-adjacent dependencies from vowels and consonants

Language acquisition requires infants' ability to track dependencies between distant speech elements. Infants as young as 3 months have been shown to successfully identify such non-adjacent dependencies between syllables, and this ability has been related to the maturity of infants' pitch processing. The present study tested whether 8- to 10-month-old infants (N = 68) can also learn dependencies at smaller segmental levels and whether the relation between dependency and pitch processing extends to other auditory features. Infants heard either syllable sequences encoding an item-specific dependency between non-adjacent vowels or between consonants. These frequent standard sequences were interspersed with infrequent intensity deviants and dependency deviants, which violated the non-adjacent relationship. Both vowel and consonant groups showed electrophysiological evidence for detection of the intensity manipulation. However, evidence for dependency learning was only found for infants hearing the dependencies across vowels, not consonants, and only in a subgroup of infants who had an above-average language score in a behavioral test. In a correlation analysis, we found no relation between intensity and dependency processing. We conclude that item-specific, segment-based non-adjacent dependencies are not easily learned by infants and if so, vowels are more accessible to the task, but only to infants who display advanced language skills.

Intermediate English as a Foreign Language learners’ formulaic language speaking proficiency: Where does the teaching of lexical chunks figure?

This research aims to investigate the impact of learning lexical chunks on the English as a Foreign Language (EFL) Saudi learners’ (aged 13 to 17) speaking fluency. The study uses an intervention with intermediate Saudi learners comprising lexical chunks based upon the books Collocation in Use and Common Idioms in English. Findings obtained from the post-test show that the experimental groups scored significantly better when compared to their performance in the pre-test of speaking fluency. On the contrary, the difference in the performance of the control group between the pre and post-tests is not significant as far as speaking fluency is concerned. The findings also show that the experimental group participants had favorable sentiments regarding explicit lexical chunk training. The research has theoretical and practical consequences in teaching and learning a foreign/second language.

Investigating variability in morphological processing with Bayesian distributional models

We investigated the processing of morphologically complex words adopting an approach that goes beyond estimating average effects and allows testing predictions about variability in performance. We tested masked morphological priming effects with English derived ('printer') and inflected ('printed') forms priming their stems ('print') in non-native speakers, a population that is characterized by large variability. We modeled reaction times with a shifted-lognormal distribution using Bayesian distributional models, which allow assessing effects of experimental manipulations on both the mean of the response distribution ('mu') and its standard deviation ('sigma'). Our results show similar effects on mean response times for inflected and derived primes, but a difference between the two on the sigma of the distribution, with inflectional priming increasing response time variability to a significantly larger extent than derivational priming. This is in line with previous research on non-native processing, which shows more variable results across studies for the processing of inflected forms than for derived forms. More generally, our study shows that treating variability in performance as a direct object of investigation can crucially inform models of language processing, by disentangling effects which would otherwise be indistinguishable. We therefore emphasize the importance of looking beyond average performance and testing predictions on other parameters of the distribution rather than just its central tendency.

Validated tests for language research with university students whose native language is English: Tests of vocabulary, general knowledge, author recognition, and reading comprehension

We present five studies aimed at developing an L1 vocabulary test for English-speaking university students. Such a test is useful as an indicator of crystallized intelligence and because vocabulary size correlates well with reading comprehension. In the first study, we tested 100 written words with four answer alternatives, based on Nation's Vocabulary Size Test. Analysis suggested two factors, which we interpreted as the possible existence of two types of difficult words: unknown words for general knowledge and unknown words for specialized knowledge. In Study 2, we attempted to develop a vocabulary test for each type of word, and these tests were then validated in Study 3. Since the test for general words proved too easy for the target population, we improved it in a fourth study by creating and testing more difficult items. Finally, a fifth study was conducted to validate the new test. Unexpectedly, Study 5 found a high correlation (r = .82) between the general knowledge vocabulary test and the specialized knowledge vocabulary test, suggesting that they measure the same latent factor, contrary to our initial assumption. Both tests have high reliability (r > .85) and correlate well (r > .4) with general knowledge, author recognition, and reading comprehension. In addition, a collection of other language tests was used and improved to verify the validity of the vocabulary tests. An exploratory factor analysis of all tests identified three factors (text comprehension, crystallized intelligence, and reading speed), with the vocabulary tests loading on the factor crystallized intelligence, which in turn correlates with reading comprehension. Structural equation modeling confirmed the interpretation.

Individual differences in artificial and natural language statistical learning

Statistical learning (SL) is considered a cornerstone of cognition. While decades of research have unveiled the remarkable breadth of structures that participants can learn from statistical patterns in experimental contexts, how this ability interfaces with real-world cognitive phenomena remains inconclusive. These mixed results may arise from the fact that SL is often treated as a general ability that operates uniformly across all domains, typically assuming that sensitivity to one kind of regularity implies equal sensitivity to others. In a preregistered study, we sought to clarify the link between SL and language by aligning the type of structure being processed in each task. We focused on the learning of trigram patterns using artificial and natural language statistics, to evaluate whether SL predicts sensitivity to comparable structures in natural speech. Adults were trained and tested on an artificial language incorporating statistically-defined syllable trigrams. We then evaluated their sensitivity to similar statistical structures in natural language using a multiword chunking task, which examines serial recall of high-frequency word trigrams-one of the building blocks of language. Participants' aptitude in learning artificial syllable trigrams positively correlated with their sensitivity to high-frequency word trigrams in natural language, suggesting that similar computations span learning across both tasks. Short-term SL taps into key aspects of long-term language acquisition when the statistical structures-and the computations used to process them-are comparable. Better aligning the specific statistical patterning across tasks may therefore provide an important steppingstone toward elucidating the relationship between SL and cognition at large.

Presupposition processing declines with age

The present study investigates the processing of presuppositions across the life span and extends the findings of the only available study on presupposition processing and typical aging by Domaneschi and Di Paola (J Pragmat 140:70-87, 2019). In an online and offline task, we investigate the impact of cognitive load during the processing and recovery of two presupposition triggers-definite descriptions and change-of-state verbs-comparing a group of younger adults with a group of older adults. The collected experimental data show that (1) presupposition recovery declines during normal aging, (2) presupposition recovery of change-of-state verbs is more cognitively demanding for older adults than the recovery of definite descriptions, and lastly (3) presupposition recovery for the change-of-state verb begin is more demanding than the change-of-state verb stop. As of today, few works have directly investigated presupposition processing across the life span. To the best of our knowledge, this is the first work revealing that cognitive load directly impacts the recovery of presuppositions across the life span, which in turn suggests an involvement of verbal working memory.

Literacy improves the comprehension of object relatives

While there is a considerable body of research indicating that the acquisition of literacy has profound effects on many aspects of language and cognition, to our knowledge, very little is known about its effects on morphosyntax. In this paper, we explore the effects of literacy on the comprehension of Spanish object relative clauses, a structure which is typically acquired by literate children about the age of 10, i.e., after a considerable amount of exposure to written language. We tested three groups of native Spanish speakers (semi-literates, late-literates and high-literates) using a picture selection task. Subject relatives were used as a control condition. All three groups performed at ceiling on subject relatives (group means of 95% or above). In contrast, we observed very large differences in performance on object relatives, with the semi-literate group performing at chance (51% correct) and the late-literate group slightly above chance (65% correct). Performance in the high-literate group was much better, although not quite at ceiling (82% correct). The results appear to support the hypothesis that literacy helps in the acquisition of some aspects of grammar. This could be partly due to differences in IQ, metalinguistic awareness, working memory and/or executive functioning. The results are also consistent with the 'training wheels' hypothesis (Dąbrowska, 2020), according to which the availability of written representations facilitates the acquisition of difficult structures by easing memory load and enabling speakers to process sentences at their own pace.

Toward a Comparative Approach to Language Acquisition

The world’s languages vary in almost every conceivable way, yet children readily learn their native language. Understanding how children can acquire such a diversity of different languages has been a long-standing goal for psychological science, yet current acquisition research is dominated by studies of children learning one particular language: English. In this article, we argue that progress toward this goal will require systematic comparisons between different languages. We propose three levels of comparison: coarse-grained comparisons contrasting unrelated languages to confirm or refute broad theoretical claims, fine-grained comparisons between closely related languages to investigate the impact of specific factors on acquisition outcomes, and within-language comparisons targeting the impact of socio-communicative differences on learning. This three-pronged comparative approach to language acquisition promises to provide new insights into the mechanisms and processes by which children acquire their native tongue under such varied linguistic and socio-communicative conditions.