Natalia Kartushina

• Visser, Ingmar; Geambasu, Andreea; Kachergis, George; Oliveira, Cátia M.; Rocha‐Hidalgo, Joscelin & Zettersten, Martin [Show all 84 contributors for this article] (2026). ManyBabies 3: A Multi‐Lab Study of Infant Algebraic Rule Learning. Developmental Science. ISSN 1363-755X. 29(6). doi: 10.1111/desc.70259. Full text in Research Archive Show summary

  ABSTRACT The ability to learn and apply rules lies at the heart of cognition. In a seminal study, Marcus et al. (1999) reported that 7‐month‐old infants learned abstract rules over syllable sequences and were able to generalize those rules to novel syllable sequences. Dozens of studies have since replicated that finding and extended it using different rules, modalities, stimuli, participants (human adults and non‐human animals) and experimental procedures. Yet questions remain about the generalizability of the core findings in Marcus et al., and sources of variation across these findings. In the current study, we address this issue by testing 839 infants (650 after exclusions) of a wide age range (5;0–12;0 months) in a multi‐laboratory (30 laboratories, [31 samples]) conceptual replication of the Marcus et al. study. This study and the analysis plan were submitted as a registered report. A mixed‐model analysis of the looking times at consistent versus inconsistent test trials indicated no significant effect. The current study therefore finds no evidence for rule‐learning; to the contrary, a Bayesian analysis of the data indicated strong evidence for a null effect. This was similarly the case for the moderating factors that were part of the design: mono‐ versus multilingualism, age, and experimental paradigm; none of these factors showed significant effects. Robustness analyses indicated that the results were not different in the case of different choices in the (pre‐)processing of the data. A follow‐up analysis for single labs indicated that there was no evidence of rule‐learning in 30 of the 31 contributed samples. The current finding raises fundamental issues about rule‐learning that are presented in the Discussion section.

• Li, Peng; Martin, Clara D. & Kartushina, Natalia (2026). Same vowels, distinct sounds. Linguistic Approaches to Bilingualism. ISSN 1879-9264. 16(5), p. 633–647. doi: 10.1075/lab.25054.li. Full text in Research Archive Show summary

  Previous research on bilingual speech production has mainly examined individuals whose first languages (L1s) differ in vowel inventories, often focusing on individual vowels and revealing distinct phonetic realizations for cross-language similar sounds. However, little is known about whether bilinguals with identical vowel inventories phonetically distinguish between their two L1s. This study examined the acoustic characteristics of 38 Basque–Spanish early bilinguals’ production of the vowels /a, e, i, o, u/ and tested whether code-switching frequency and amount of language use influence individual vowels and vowel space in each language. The results showed that /i/ was lower and /i, o, u/ were more fronted in Basque than in Spanish. In addition, bilinguals exhibited a larger vowel space in Spanish compared to Basque, with frequent code-switching diminishing this difference regardless of language use. These findings provide updated acoustic norms for Gipuzkoan Basque and Northern Castilian Spanish vowels and demonstrate that code-switching experience shapes phonetic realizations in early bilinguals whose L1s share identical vowel inventories.

• Turker, Sabrina; Kartushina, Natalia & Golestani, Narly (2026). Speech Sound Production in Adults with Dyslexia. Brain Sciences. 16(5). doi: 10.3390/brainsci16050448. Full text in Research Archive Show summary

  Background: Dyslexia is a reading disorder that is associated with phonological processing and awareness difficulties. However, little is known about phonetic production in dyslexia. Whereas individual differences in speech sound perception were linked to native and foreign speech sound production in typical readers, this remains to be explored in dyslexia. Given the phonetic processing deficits frequently encountered in dyslexia, we aimed to pinpoint potential differences in the acoustic realization of native phonemic production in adults with dyslexia. Methods: Ten adults with dyslexia and ten age-matched typical readers produced 24 native-language minimal voiced–voiceless word pairs across three places of articulation (labial, dental, velar) in a reading task. Acoustic analyses addressed phonemic category size, between-category distance, and voice onset time (VOT). Pseudoword reading performance served as an index of phonological decoding ability. Results: For category size, we observed a trend-level group-by-type interaction (p = 0.059, η2 = 0.04): both groups showed larger category sizes for voiced than voiceless consonants, but this difference was numerically larger in typical readers. Between-category distance showed a marginal group effect (p = 0.089, η2 = 0.14), with larger differences between categories in dyslexia. VOT showed the expected effect of voicing, but no group differences. Conclusions: Our results indicate broadly preserved speech production in dyslexia, alongside subtle differences in category separation and size in dyslexia, marked by considerable inter-individual variability.

• Piazza, Giorgio; Kartushina, Natalia; Souganidis, Christoforos; Flege, James E. & Martin, Clara D. (2026). Speech onset time at home or in the lab: The role of testing environment and experimenter presence. Behavior Research Methods. ISSN 1554-351X. 58(1). doi: 10.3758/s13428-025-02918-6. Full text in Research Archive Show summary

  Psycholinguistic research has become increasingly reliant on online experimentation, making it an attractive approach for studying speech production. However, concerns remain about data quality and participant engagement in online settings. In this preregistered study, we used two tasks—picture naming and reading aloud—to test whether the lexical frequency effect (low-frequency words having shorter speech onset times than high-frequency words) could be reliably detected in the online environment (run at home), both with and without experimenter supervision. Participants completed the same two tasks at home and in the lab. Half of the participants performed both tasks with supervision and the other half unsupervised. In the naming task, all conditions yielded consistent frequency effects (~27–41 ms), comparable to previous online and lab findings. In the reading aloud task, lexical frequency effect emerged in all conditions except for the home-supervised, where the effect was in the expected direction but nonsignificant (~12 ms). Notably, participants were overall faster at home than in the lab (~10 ms), and unsupervised settings yielded the largest effect sizes. This suggests that experimenter presence may inadvertently dampen subtle effects, possibly due to increased self-monitoring or reduced comfort. Such findings indicate the reliability of online platforms for speech production research in psycholinguistics and highlight the nuanced influence of supervision on speech outcomes.

• Cameron, Sarah; Kartushina, Natalia; Lundquist, Björn & Caffarra, Sendy (2026). Linear distance modulates P600 amplitude for gender agreement: An ERP study in Norwegian. Brain Research. ISSN 0006-8993. 1887. doi: 10.1016/j.brainres.2026.150390. Full text in Research Archive Show summary

  ormer ERP studies have shown that linear distance (number of intervening words between two agreeing elements in a sentence) modulates P600 amplitude for gender agreement violations. However, these studies have primarily focused on across-phrase dependencies, making it difficult to tease apart the effects of linear distance from those of structural distance (number of intervening phrases between two agreeing elements in a sentence). Norwegian, an understudied language in gender processing literature, permits manipulation of linear distance while holding structural distance constant. We tested 36 native Norwegian speakers with EEG, comparing three violation types: noun-suffix (within-word), determiner-noun (within-phrase), and noun-predicative adjective (across-phrase). Our aims were to: 1) assess processing of within-word gender violations, which, to our knowledge has not previously been done; 2) examine the effect of linear distance on within-phrase gender agreement by comparing processing of noun-suffix and determiner-noun dependencies; and 3) establish an ERP baseline for Norwegian gender processing. All three violation types elicited P600 responses, indicating repair/reanalysis processes. Noun–predicative adjective violations additionally produced a left anterior negativity, and determiner–noun violations showed a late frontal negativity. The noun-suffix P600 demonstrates that within-word gender violations recruit similar repair mechanisms as between-word violations. Moreover, the noun-suffix P600 was larger than the determiner–noun P600, likely due to either weaker constituent links resulting from longer distance, or longer distances reducing repairs due to a cost–benefit tradeoff. The findings from this study show that 1) within-word violations engage the same reanalysis processes as between-word violations, 2) within-phrase gender agreement processing is sensitive to linear distance, and 3) Norwegian exhibits similar ERP correlates of gender processing as those found for other languages.

• Oshchepkova, Ekaterina; Kartushina, Natalia & Kovyazina, Maria (2025). Understanding of ironic and literal utterances in 4–9-year-old typically developing children: role of age, narrative skills, emotion comprehension and executive functions. Frontiers in Psychology. 16. doi: 10.3389/fpsyg.2025.1718227. Full text in Research Archive Show summary

  Language comprehension is essential to communication, yet understanding varies between literal meaning and verbal irony. While children grasp words' surface meanings, interpreting verbal irony requires them to consider context and infer the speaker's true intent, revealing a deeper layer of meaning. What factors contribute to this complex skill? The current study examined the impact of sex, narrative skills, executive functions (working memory and inhibitory control), theory of mind and emotion comprehension, while controlling for age, on understanding of literal statements and verbal irony in 267 typically developing 4–9-year old children (130 boys). To assess children's irony comprehension, we presented them with cartoon scenarios and asked to choose an emoji to indicate whether a parent's reaction was literal or ironic. A full-null model approach was used to examine the impact of children's cognitive, executive, emotional, and narrative skills on their irony understanding, where the full contained our factors of interest and the null contained only age and sex. The results indicated that age was the only factor related to literal meaning comprehension. In contrast, both age and working memory were significantly related to irony understanding. These findings can be used as a foundation for developing training to enhance non-literal language and pragmatic skills in children.

• Rosslund, Audun; Mayor, Julien & Kartushina, Natalia (2025). Norwegian parents do not modulate infant-directed speech based on their infants’ attributed word knowledge. Developmental Psychology. ISSN 0012-1649. doi: 10.1037/dev0002077. Full text in Research Archive Show summary

  Infant-directed speech (IDS), the register caregivers often use when interacting with infants, has been suggested to facilitate language learning. To assess its didactic role, we examined the acoustic modifications parents make in IDS for words they attribute to their infant as unknown, versus known, by analyzing data from three studies of Norwegian IDS with 8- to 18-month-old infants (N = 132 infants, N = 182 parents). Parents’ speech was recorded during a shared-reading interaction with their infant and with an experimenter (as a control register), ensuring that speech content was matched across participants and registers. Contrary to our hypotheses, we found no evidence that parents emphasized IDS for words attributed as unknown. Furthermore, Bayesian analyses suggested that Norwegian parents do not modulate IDS based on infants’ attributed word knowledge. Thus, our findings do not support the notion that parents use IDS as a didactic strategy to teach individual words, underscoring alternative motivations for engaging in such speech.

• Rosslund, Audun; Kartushina, Natalia; Serres, Nora Rose & Mayor, Julien (2025). Early Vocabulary Acquisition: From Birth Order Effect to Child-to-Caregiver Ratio. Child Development. ISSN 0009-3920. 96(4), p. 1343–1353. doi: 10.1111/cdev.14251. Full text in Research Archive Show summary

  Growing up with multiple siblings might negatively affect language development. This study examined the associations between birth order, sibling characteristics and parent-reported vocabulary size in 6163 Norwegian 8- to 36-month-old children (51.4% female). Results confirmed that birth order was negatively associated with vocabulary, yet exhibited a U-shaped pattern. A data-driven measure of “child-to-caregiver ratio” in the household was developed, in which old-enough siblings—females 1–3 years earlier than males—were considered caregivers for their younger siblings. This measure explained variance in vocabulary better than birth order, and indicates sex-differences in the age at which older siblings contribute to, rather than deplete, available resources. A child-to-caregiver ratio might better capture the interplay between language-learning resources and demands within households.

• Allegretta, Silvia; Gavrilova, Margarita; Kartushina, Natalia; Mayor, Julien; Roch, Maja & Kunst, Jonas R. (2025). Parental Attitudes and Children’s Language Development: A Cross-Cultural Evaluation of the Early Parenting Attitudes Questionnaire. Collabra: Psychology. ISSN 2474-7394. 11(1). doi: 10.1525/collabra.130882. Full text in Research Archive Show summary

  The Early Parenting Attitudes Questionnaire (EPAQ; Hembacher & Frank, 2020) was developed in the U.S. to assess parents’ beliefs, knowledge, ideas, and attitudes about parenting. Given the diversity of parenting practices among cultures, it is essential to establish the cross-cultural validity of the instruments used to measure them. For this reason, this study aims at (1) assessing the psychometric properties of the EPAQ in Norway, Russia, and the U.K. and (2) investigating whether the underlying structure aligns with the original one observed in the U.S. Moreover, we aimed at (3) exploring the potential relationship between parental attitudes and children’s language development using MacArthur-Bates Communicative Development Inventories (CDI; Fenson et al. 2007). Our sample consisted of 3333 parents of children between 0 and 156 months from Norway (n = 1060), the U.K. (n = 656) , and Russia (n = 1617). Analyses revealed a different factor solution in the countries of our sample, as compared to the original three-factor solution found in the original American sample. Especially in Russia, the structure of parental attitudes as measured by the EPAQ differs both from the original factor solution and from the factor solution identified in Norway and the U.K. Therefore, at least in the Russian context, different culture-sensitive scales need to be developed and, generally, new items for the EPAQ should be developed for further refinement. Moreover, our analyses highlighted a significant negative association between the factor Communicative and Emotional Detachment and vocabulary scores as a function of the child’s age in Russia.

• Kartushina, Natalia & D., Martin Clara (2025). Talker-variability in visual feedback articulatory training: Transfer to words, long-term maintenance, and generalization. Journal of the Acoustical Society of America. ISSN 0001-4966. 157(3), p. 2117–2126. doi: 10.1121/10.0036217. Full text in Research Archive Show summary

  An important challenge in second language acquisition is learning how to produce novel sounds. Visual-acoustic feedback training has been shown to improve second language production, but it is still unclear whether training on isolated sounds transfers to words and is maintained over time. Forty-six Spanish speakers were trained to produce unfamiliar French vowels /e/–/ɛ/ through exposure to either single- or multiple-talker stimuli. On each trial, they heard a vowel, produced it, and received feedback showing the position of their vowel and the target in the acoustic space. Both groups showed improvements in vowel production, which transferred to words and were maintained 12 days later. However, better generalization—more accurate production when repeating vowels after an unfamiliar speaker—was maintained only in the multiple-talker group. This study shows that visual-acoustic feedback training is an effective method for improving second language production as the gains of such training demonstrate three key features for pedagogical practice: transfer, generalization, and maintenance.

• Rosslund, Audun; Varjola, Nina; Mayor, Julien & Kartushina, Natalia (2025). Longitudinal changes in consonant production in infant-directed speech and infants’ early speech production from 6 to 12 months. Infant Behavior and Development. ISSN 0163-6383. 78. doi: 10.1016/j.infbeh.2024.102018. Full text in Research Archive Show summary

  Previous research suggests that acoustic features of infant-directed speech (IDS) might be beneficial for infants’ language development. However, consonants have gained less attention than vowels and prosody. In the current study, we examined voice onset time (VOT) – a distinguishing cue for stop consonant contrasts – in IDS and adult-directed speech (ADS), and its relation to infants’ speech production. We used a longitudinal sample of 48 Norwegian parent-infant dyads. Parents’ IDS and ADS were recorded in-lab at three timepoints (infants’ age: 6, 9, 12 months), and the VOTs of the stop consonants /b-p/, /d-t/, and /g-k/ were measured. In addition, at each timepoint, parents reported their infants’ production of the same consonants, as well as their babbling. Hypotheses were preregistered, and we used full-null model comparisons to minimise type I-errors in the analyses. Our results demonstrate that, while controlling for speaking rate, in IDS, parents’ VOTs were longer in voiceless stops, but shorter in voiced stops, resulting in overall less distinct consonant contrasts compared to ADS. Further, VOTs in IDS approached ADS values with infants’ age. However, we found no relationship between parents’ VOTs and infants’ consonant production or babbling. Consonants, like vowels, appear to be less distinct in IDS than ADS, thus reinforcing the interpretation that IDS may serve an attentional and/or affective aim, rather than a didactic purpose.

• Muñoz, Luis Eduardo; Kartushina, Natalia & Mayor, Julien (2024). Sustained pacifier use is associated with smaller vocabulary sizes at 1 and 2 years of age: A cross-sectional study. Developmental Science. ISSN 1363-755X. doi: 10.1111/desc.13477. Full text in Research Archive Show summary

  Pacifier use during childhood has been hypothesized to interfere with language processing, but, to date, there is limited evidence revealing detrimental effects of prolonged pacifier use on infant vocabulary learning. In the present study, parents of 12- and 24-month-old infants were recruited in Oslo (Norway). The sample included 1187 monolingual full-term born (without visual, auditory, or cognitive impairments) infants: 452 (230 girls; 222 boys) 12-month-olds and 735 (345 girls; 390 boys) 24-month-olds. Parents filled out an online Norwegian Communicative Development Inventory (CDI), which assesses the vocabulary in comprehension and production for 12-month-old infants and in production only for 24-month-old infants. CDI scores were transformed into age- and sex-adjusted percentiles using Norwegian norms. Additionally, parents retrospectively reported their child's daytime pacifier use, in hours, at 2-month intervals, from birth to the assessment date. Maternal education was used to control, in the analyses, for the socio-economic status. We found that greater pacifier use in an infant's lifespan was associated with lower vocabulary size. Pacifier use later in life was more negatively associated with vocabulary size than precocious use, and increased the odds of being a low language scorer. In sum, our study moves beyond the findings of momentary effects of experimentally induced “impairment” in articulators’ movement on speech perception and suggests that, from 12 months of age, constraints on the infant's speech articulators (pacifier use) may be negatively associated with word comprehension and production.

• Sinkeviciute, Akvile; Mayor, Julien; Vulchanova, Mila Dimitrova & Kartushina, Natalia (2024). Active Language Modulates Color Perception in Bilinguals. Language Learning. ISSN 0023-8333. 74(1), p. 40–71. doi: 10.1111/lang.12645. Full text in Research Archive Show summary

  Color terms divide the color spectrum differently across languages. Previous studies have reported that speakers of languages that have different words for light and dark blue (e.g., Russian siniy and goluboy) discriminate color chips sampled from these two linguistic categories faster than speakers of languages that use one basic color term for blue (e.g., English blue). This effect has been reported to be disrupted when participants engaged in a verbal interference task, suggesting that active language use can modulate the linguistic category effect. The current study provided a stringent test of this hypothesis by examining color discrimination under verbal interference in bilinguals speaking Lithuanian (two blue categories) and Norwegian (one blue category). The results revealed that the language activated during verbal interference had a significant impact on bilinguals’ color discrimination. Specifically, Lithuanian–Norwegian bilinguals exhibited a color category effect only when performing the task under verbal interference in Lithuanian but not in Norwegian. This demonstrated, within the same individuals, the momentary effect of active language processing on color perception.

• Rosslund, Audun; Mayor, Julien; Cristia, Alejandrina & Kartushina, Natalia (2024). Native and non-native vowel discrimination in 6-month-old Norwegian infants. Infant Behavior and Development. ISSN 0163-6383. 77. doi: 10.1016/j.infbeh.2024.101992. Full text in Research Archive Show summary

  In the current preregistered study, we tested n = 67 6-month-old Norwegian infants’ discrimination of a native vowel contrast /y-i/ and a non-native (British) vowel contrast /ʌ-æ/ in an eye-tracking habituation paradigm. Our results showed that, on a group level, infants did not discriminate either contrast. Yet, exploratory analyses revealed a negative association between infants’ performance in each experiment, that is, better discrimination of the native contrast was associated with worse discrimination of the non-native contrast. Potentially, infants in this study might have been on the cusp of perceptual reorganisation towards their native language.

• Rosslund, Audun; Kartushina, Natalia & Mayor, Julien (2024). Associations between shared book reading, daily screen time and infants' vocabulary size. Journal of Child Language. ISSN 0305-0009. p. 1–13. doi: 10.1017/S0305000924000291. Full text in Research Archive Show summary

  In the current pre-registered study, we examined the associations between shared book reading, daily screen time, and vocabulary size in 1,442 12- and 24-month-old Norwegian infants. Our results demonstrate a positive association between shared reading and vocabulary in both age groups, and a negative association between screen time and vocabulary in 24-month-olds. Exploratory analyses revealed that the positive relationship between shared reading and expressive vocabulary in 12-month-olds was stronger in lower SES groups, suggesting that shared reading may act as a compensatory mechanism attenuating potentially impoverished learning environment and parent-infant interactions in low-SES families.

• Zettersen, Martin; Cox, Christopher J.; Bergmann, Christina; Tsui, Angeline Sin Mei; Soderstrom, Melanie & Mayor, Julien [Show all 15 contributors for this article] (2024). Evidence for Infant-directed Speech Preference Is Consistent Across Large-scale, Multi-site Replication and Meta-analysis. Open Mind. 8, p. 439–461. doi: 10.1162/opmi_a_00134. Full text in Research Archive Show summary

  There is substantial evidence that infants prefer infant-directed speech (IDS) to adult-directed speech (ADS). The strongest evidence for this claim has come from two large-scale investigations: i) a community-augmented meta-analysis of published behavioral studies and ii) a large-scale multi-lab replication study. In this paper, we aim to improve our understanding of the IDS preference and its boundary conditions by combining and comparing these two data sources across key population and design characteristics of the underlying studies. Our analyses reveal that both the meta-analysis and multi-lab replication show moderate effect sizes (d ≈ 0.35 for each estimate) and that both of these effects persist when relevant study-level moderators are added to the models (i.e., experimental methods, infant ages, and native languages). However, while the overall effect size estimates were similar, the two sources diverged in the effects of key moderators: both infant age and experimental method predicted IDS preference in the multi-lab replication study, but showed no effect in the meta-analysis. These results demonstrate that the IDS preference generalizes across a variety of experimental conditions and sampling characteristics, while simultaneously identifying key differences in the empirical picture offered by each source individually and pinpointing areas where substantial uncertainty remains about the influence of theoretically central moderators on IDS preference. Overall, our results show how meta-analyses and multi-lab replications can be used in tandem to understand the robustness and generalizability of developmental phenomena.

• Schreiner, Melanie S.; Zettersten, Martin; Bergmann, Christina; Frank, Michael C.; Fritzsche, Tom & Gonzalez-Gomez, Nayeli [Show all 16 contributors for this article] (2024). Limited evidence of test-retest reliability in infant-directed speech preference in a large preregistered infant experiment. Developmental Science. ISSN 1363-755X. doi: 10.1111/desc.13551. Full text in Research Archive Show summary

  Test-retest reliability—establishing that measurements remain consistent across multiple testing sessions—is critical to measuring, understanding, and predicting individual differences in infant language development. However, previous attempts to establish measurement reliability in infant speech perception tasks are limited, and reliability of frequently used infant measures is largely unknown. The current study investigated the test-retest reliability of infants’ preference for infant-directed speech over adult-directed speech in a large sample (N = 158) in the context of the ManyBabies1 collaborative research project. Labs were asked to bring in participating infants for a second appointment retesting infants on their preference for infant-directed speech. This approach allowed us to estimate test-retest reliability across three different methods used to investigate preferential listening in infancy: the head-turn preference procedure, central fixation, and eye-tracking. Overall, we found no consistent evidence of test-retest reliability in measures of infants’ speech preference (overall r = 0.09, 95% CI [−0.06,0.25]). While increasing the number of trials that infants needed to contribute for inclusion in the analysis revealed a numeric growth in test-retest reliability, it also considerably reduced the study's effective sample size. Therefore, future research on infant development should take into account that not all experimental measures may be appropriate for assessing individual differences between infants.

• Oshchepkova, Ekaterina S.; Kartushina, Natalia & Tarasova, Kristina S. (2024). A Questionnaire for the Assessment of Pragmatic Competence in Children aged 5-8. Clinical Psychology and Special Education. ISSN 2304-0394. 13(1), p. 128–154. doi: 10.17759/cpse.2024130109. Full text in Research Archive
• Soderstrom, Melanie; Rocha-Hidalgo, Joscelin; Munoz, Luis Eduardo; Bochynska, Agata; Werker, Janet F. & Skarabela, Barbora [Show all 42 contributors for this article] (2024). Testing the relationship between preferences for infant-directed speech and vocabulary development: A multi-lab study. Journal of Child Language. ISSN 0305-0009. doi: 10.1017/S0305000924000254. Full text in Research Archive Show summary

  From early on, infants show a preference for infant-directed speech (IDS) over adult-directed speech (ADS), and exposure to IDS has been correlated with language outcome measures such as vocabulary. The present multi-laboratory study explores this issue by investigating whether there is a link between early preference for IDS and later vocabulary size. Infants’ preference for IDS was tested as part of the ManyBabies 1 project, and follow-up CDI data were collected from a subsample of this dataset at 18 and 24 months. A total of 341 (18 months) and 327 (24 months) infants were tested across 21 laboratories. In neither preregistered analyses with North American and UK English, nor exploratory analyses with a larger sample did we find evidence for a relation between IDS preference and later vocabulary. We discuss implications of this finding in light of recent work suggesting that IDS preference measured in the laboratory has low test-retest reliability.

• Rosslund, Audun; Mayor, Julien; Mundry, Roger; Singh, Arun Prakash; Cristia, Alejandrina & Kartushina, Natalia (2024). A longitudinal investigation of the acoustic properties of infant-directed speech from 6 to 18 months. Royal Society Open Science. 11(11), p. 1–33. doi: 10.1098/rsos.240572. Full text in Research Archive Show summary

  Caregivers often modulate their speech when interacting with infants, adapting a register that has been suggested to have attentional, affective and didactic purposes. The present preregistered study examined the longitudinal trajectories of a diverse range of acoustic features of infant-directed speech (IDS) and compared these with adult-directed speech (ADS), in Norwegian parents of 6- to 18-month-old infants. Sixty-nine families participated. Throughout five laboratory visits across one year, parents were recorded reading a picture-book to their infant (IDS) and an experimenter (ADS). The book was designed to tightly control for the linguistic content and context of speech between participants, timepoints and registers. Analyses of a total of 54 594 vowels and 22 958 phrases revealed, first, an overall effect of register: parents used higher pitch, wider pitch range, slower articulation rate, longer vowel duration and more variable and less distinct vowels in IDS than in ADS. Second, significant register-by-age interactions indicated that parents’ IDS, compared with their ADS, featured wider pitch range, larger vowel space and shorter vowel duration in older as compared with younger infants, while pitch, articulation rate and vowel variability and distinctiveness remained relatively stable with age. Results are discussed in the context of the proposed functions of IDS.

• Roepstorff, Ida Torp; Mayor, Julien; Havighurst, Sophie Seychelle & Kartushina, Natalia (2024). Same name, different representational levels? Misalignment of indirect parent-reported and direct alternative forced choice measures of emotion word comprehension in preschool children. Journal of Child Language. ISSN 0305-0009. p. 1–16. doi: 10.1017/S0305000923000727. Full text in Research Archive Show summary

  This study assessed the relationship between preschoolers’ directly and indirectly assessed emotion word comprehension. Forty-nine two-to-five-year-old Norwegian children were assessed in a tablet-based 4-alternative forced choice (AFC) task on their comprehension of six basic and six complex emotions using facial expression photographs. Parents reported emotion word comprehension and production of the same words. Parent-reported emotion word production interacted with age to predict preschoolers’ performance, with a parent-child alignment only observed for older children. Parent-reported word comprehension did not significantly predict accuracy. The results suggest that, in preschoolers, direct and indirect assessments might address distinct representational levels of emotion word comprehension.

• Li, Peng; Flege, James Emil; Martin, Clara D. & Kartushina, Natalia (2023). Speech stability across time: Evidence from Norwegian vowels in spontaneous speech production. In Skarnitzl, Radek & Volin, Jan (Ed.), Proceedings of the 20th International Congress of Phonetic Sciences. International Phonetic Association. ISSN 9788090811423. p. 1201–1205. Full text in Research Archive
• Rosslund, Audun; Hagelund, Silje; Mayor, Julien & Kartushina, Natalia (2023). Mothers' and fathers' infant-directed speech have similar acoustic properties, but these are not associated with direct or indirect measures of word comprehension in 8-month-old infants. Journal of Child Language. ISSN 0305-0009. doi: 10.1017/S0305000923000557. Full text in Research Archive Show summary

  Previous research on infant-directed speech (IDS) and its role in infants’ language development has largely focused on mothers, with fathers being investigated scarcely. Here we examine the acoustics of IDS as compared to adult-directed speech (ADS) in Norwegian mothers and fathers to 8-month-old infants, and whether these relate to direct (eye-tracking) and indirect (parental report) measures of infants’ word comprehension. Forty-five parent-infant dyads participated in the study. Parents (24 mothers, 21 fathers) were recorded reading a picture book to their infant (IDS), and to an experimenter (ADS), ensuring identical linguistic context across speakers and registers. Results showed that both mothers’ and fathers’ IDS had exaggerated prosody, expanded vowel spaces, as well as more variable and less distinct vowels. We found no evidence that acoustic features of parents’ speech were associated with infants’ word comprehension. Potential reasons for the lack of such a relationship are discussed.

• Lo, Chang Huan; Hermes, Jonas; Kartushina, Natalia; Mayor, Julien & Mani, Nivedita (2023). e-Babylab: An open-source browser-based tool for unmoderated online developmental studies. Behavior Research Methods. ISSN 1554-351X. doi: 10.3758/s13428-023-02200-7. Full text in Research Archive
• Oshchepkova, Ekaterina S.; Kartushina, Natalia & Razmakhnina, Ksenia O. (2023). Bilingualism and Development of Literacy in Children: A Systematic Review. Psychology in Russia: State of the Art. ISSN 2074-6857. 16(1), p. 3–25. doi: 10.11621/pir.2023.0101. Full text in Research Archive Show summary

  Background. The importance of biliteracy in bilingual children’s development has been widely investigated and discussed for the last several decades, suggesting beneficial effects of writing and reading in two languages for bilingual children as well as for adult second language learners. Objective. To analyze research on the link between bilingualism and literacy development in two or more languages and the factors that may influence a successful or problematic biliteracy acquisition. RQ (1): What is the relationship between bilingualism and literacy of bilingual children? RQ (2): What strategies are used to develop biliteracy? Design. The review analyzes 50 studies of literacy development in bilingual children. The selected articles have been separated based on their methodology: 25 articles gave a critical analysis of more than 1,100 studies on the topic, strengthening the theoretical basis of existing research, and 25 other articles were empirical research articles demonstrating practical evidence for the former. Results. Our analysis revealed that literacy in bilinguals, or biliteracy, can be seen as a necessary condition for fluent development of bilingualism, though it is not a necessary condition (which is explained by the difference between structures of specific languages and writing systems, instruction in literacy, and cognitive baggage invoked by the task used to measure the skill) (Bialystok, 2002). Research suggests that bilingualism impacts children's ultimate acquisition of literacy via the beneficial effects of bilingualism overall: advanced biliteracy boosts the development of phonological and phonemic awareness and metacognitive abilities. Thus, biliteracy can be considered as an advantage in terms of maintaining bilingual acquisition in general and developing writing skills in particular. Conclusion. There is a lack of studies on the development of writing skills in different educational contexts, across countries and cultures, which must be addressed and complemented by new empirical research. Research will enable policymakers to improve educational programs in accordance with the needs of bilingual children, who are the majority in the current global population.

• Kartushina, Natalia; Soto, David & Martin, Clara (2022). Metacognition in Second Language Speech Perception and Production. Language Learning. ISSN 0023-8333. doi: 10.1111/lang.12549. Full text in Research Archive Show summary

  In this study, we assessed metacognition in nonnative language speech perception and production. Spanish novice learners of French identified and produced the French vowel contrast /ø/–/œ/ and, on each trial, rated their confidence in their responses. Participants’ confidence in perception predicted their identification accuracy, suggesting that novice learners’ metacognitive skills in nonnative speech perception are efficient at the onset of language learning. However, participants’ confidence in production did not align with a fine-grained precision measure of their own production (indexed by Mahalanobis distance to the native French target-vowel space) nor with a categorical measure of production (in terms of being within/outside the native speakers’ zone), indicating that metacognition in nonnative sound production is not yet efficient in novice learners. Overall, confidence ratings were similar and highly correlated between the perception and production tasks, but there was no association between the two domains in task performance or metacognitive ability. We discuss the ramifications of these findings for language learning theories and language teaching strategies as well as for the ongoing debate about the perception–production relationship.

• Kartushina, Natalia & Mayor, Julien (2022). Coping with dialects from birth: Role of variability on infants’ early language development. Insights from Norwegian dialects. Developmental Science. ISSN 1363-755X. 26(1), p. 1–19. doi: 10.1111/desc.13264. Full text in Research Archive Show summary

  Previous research suggests that exposure to accent variability can affect toddlers’ familiar word recognition and word comprehension. The current preregistered study addressed the gap in knowledge on early language development in infants exposed to two dialects from birth and assessed the role of dialect similarity in infants’ word recognition and comprehension. A 12-month-old Norwegian-learning infants, exposed to native Norwegian parents speaking the same or two Norwegian dialects, took part in two eye-tracking tasks, assessing familiar word form recognition and word comprehension. Their parents’ speech was assessed for similarity by native Norwegian speakers. First, in contrast to previous research, our results revealed no listening preference for words over nonwords in both monodialectal and bidialectal infants, suggesting potential language-specific differences in the onset of word recognition. Second, the results showed evidence for word comprehension in monodialectal infants, but not in bidialectal infants, suggesting that exposure to dialectal variability impacts early word acquisition. Third, perceptual similarity between parental dialects tendentially facilitated bidialectal infants’ word recognition and comprehension. Forth, the results revealed a strong correlation between the raters and parents’ assessment of similarity between dialects, indicating that parental estimations can be reliably used to assess infants’ speech variability at home. Finally, our results revealed a strong relationship between word recognition and comprehension in monodialectal infants and the absence of such a relationship in bidialectal infants, suggesting that either these two skills do not necessarily align in infants exposed to more variable input, or that the alignment might occur at a later stage.

• Kartushina, Natalia; Kovyazina, M.S.; Oshchepkova, E.S. & Shatskaya, A.N. (2022). Factors influencing the macro- and microstructure of narratives in preschoolers of bilingual regions of Russia. Voprosy psihologii. ISSN 0042-8841. 68(3), p. 35–47. Full text in Research Archive
• Bergmann, Christina; Dimitrova, Nevena; Alaslani, Khadeejah; Almohammadi, Alaa; Alroqi, Haifa & Aussems, Suzanne [Show all 19 contributors for this article] (2022). Young children’s screen time during the first COVID-19 lockdown in 12 countries. Scientific Reports. 12(2015). doi: 10.1038/s41598-022-05840-5. Full text in Research Archive Show summary

  Abstract Older children with online schooling requirements, unsurprisingly, were reported to have increased screen time during the first COVID-19 lockdown in many countries. Here, we ask whether younger children with no similar online schooling requirements also had increased screen time during lockdown. We examined children’s screen time during the first COVID-19 lockdown in a large cohort (n = 2209) of 8-to-36-month-olds sampled from 15 labs across 12 countries. Caregivers reported that toddlers with no online schooling requirements were exposed to more screen time during lockdown than before lockdown. While this was exacerbated for countries with longer lockdowns, there was no evidence that the increase in screen time during lockdown was associated with socio-demographic variables, such as child age and socio-economic status (SES). However, screen time during lockdown was negatively associated with SES and positively associated with child age, caregiver screen time, and attitudes towards children’s screen time. The results highlight the impact of the COVID-19 lockdown on young children’s screen time.

• Rosslund, Audun; Mayor, Julien; Óturai, Gabriella & Kartushina, Natalia (2022). Parents’ hyper-pitch and low vowel category variability in infant-directed speech are associated with 18-month-old toddlers’ expressive vocabulary. Language Development Research. 2(1), p. 223–267. doi: 10.34842/2022.0547. Full text in Research Archive Show summary

  The present study examines the acoustic properties of infant-directed speech (IDS) as compared to adult-directed speech (ADS) in Norwegian parents of 18-month-old toddlers, and whether these properties relate to toddlers’ expressive vocabulary size. Twenty-one parent-toddler dyads from Tromsø, Northern Norway participated in the study. Parents (16 mothers, 5 fathers), speaking a Northern Norwegian dialect, were recorded in the lab reading a storybook to their toddler (IDS register), and to an experimenter (ADS register). The storybook was designed for the purpose of the study, ensuring identical linguistic contexts across speakers and registers, and multiple representations of each of the nine Norwegian long vowels. We examined both traditionally reported measures of IDS: pitch, pitch range, vowel duration and vowel space expansion, but also novel measures: vowel category variability and vowel category distinctiveness. Our results showed that Norwegian IDS, as compared to ADS, had similar characteristics as in previously reported languages: higher pitch, wider pitch range, longer vowel duration, and expanded vowel space area; in addition, it had more variable vowel categories. Further, parents’ hyper-pitch, that is, the within-parent increase in pitch in IDS as compared to ADS, and lower vowel category variability in IDS itself, were related to toddlers' vocabulary. Our results point towards potentially facilitating roles of increase in parents’ pitch when talking to their toddlers and of consistency in vowel production in early word learning.

• Kartushina, Natalia; Mani, Nivedita; Aslı, Aktan-Erciyes; Alaslani, Khadeejah; Aldrich, Naomi J. & Almohammadi, Alaa [Show all 52 contributors for this article] (2022). COVID-19 first lockdown as a window into language acquisition: associations between caregiver-child activities and vocabulary gains. Language Development Research. 2, p. 1–36. doi: 10.34842/abym-xv34. Full text in Research Archive Show summary

  The COVID-19 pandemic, and the resulting closure of daycare centers worldwide, led to unprecedented changes in children’s learning environments. This period of increased time at home with caregivers, with limited access to external sources (e.g., daycares) provides a unique opportunity to examine the associations between the caregiver-child activities and children’s language development. The vocabularies of 1742 children aged8-36 months across 13 countries and 12 languages were evaluated at the beginning and end of the first lockdown period in their respective countries(from March to September 2020). Children who had less passive screen exposure and whose caregivers read more to them showed larger gains in vocabulary development during lockdown, after controlling for SES and other caregiver-child activities. Children also gained more words than expected (based on normative data) during lockdown; either caregivers were more aware of their child’s development or vocabulary development benefited from intense caregiver-child interaction during lockdown.

• Oshepkova, Ekaterina; Kartushina, Natalia & Shatskaya, Arina (2022). Features of narratives in children growing up in a bilingual environment. Полилингвиальность и транскультурные практики. ISSN 2618-897X. 19(1), p. 6–18. Full text in Research Archive
• Bukhalenkova, Daria; Veraksa, Aleksander; Gavrilova, Margarita & Kartushina, Natalia (2022). Emotion Understanding in Bilingual Preschoolers. Behavioral Sciences. 12(4). doi: 10.3390/bs12040115. Full text in Research Archive Show summary

  The effects of bilingualism on child development have been extensively examined in last decades. Research reveals that simultaneous use of two or more languages affects child’s language development, cognitive and social skills. The current study focuses on the so-far understudied theory of emotion understanding in bilingual children. A cohort of 593 bilingual and monolingual 5–6-year-olds took the Russian version of the Test of Emotion Comprehension (TEC) that assesses three components of emotion understanding: emotion understanding of external causes of emotions, reflective causes of emotions; and mental causes of emotions. Our results revealed no group differences between overall emotion understanding and understanding of external and reflective causes of emotions. However, monolingual children had a slightly better understanding of mental causes of emotions compared to bilingual children, when controlling for age, gender, and non-verbal intelligence. These results suggest that children growing up in bilingual environments might require more time and/or language/culture exposure to master the ability to understand mental causes of emotions, taking into account cultural differences, as well as the semantic and lexical differences in emotion labelling and emotion expression in each language.

• Bukhalenkova, Daria; Veraksa, Aleksander N.; Gavrilova, Margarita & Kartushina, Natalia (2021). The Role of Russian Parents’ Education in the Development of Intuitive Theories of Parenting. Obrazovanie i samorazvitie. ISSN 1991-7740. 16(1), p. 82–92. doi: 10.26907/esd16.1.07. Full text in Research Archive Show summary

  Previous research in English-speaking countries has shown that parental education predicts significantly parental attitudes and theories about parenting which, in turn, guide parental interaction with their child and might impact the child’s mental development. However, to the best of our knowledge, there has been no research aimed at studying the role of parental education in shaping the views of Russian parents on their children’s education and development. The current study aimed to analyze the role of Russian parents’ education in their intuitive theories of parenting, by controlling for the region where the families live, and taking into account the age and sex of their child. Intuitive theories of parenting were studied using the Early Parental Attitudes Questionnaire (EPAQ). The sample consisted of 995 parents who have children aged 1 to 7 and live in Moscow, the Republic of Sakha (Yakutia) and Republic North Ossetia in Russian Federation. Two profiles of intuitive theories of parenting were identified. Differences and similarities in intuitive theories of parenting between regions, when controlling for parents' level of education were also identified. The results characterize modern parenthood in three geographically distant Russian regions and can be useful in understanding the profile of a modern parent, as well as for developing educational programmes aimed at self-development and increasing parental competence in Russian parents.

• Lo, Chang Huan; Rosslund, Audun; Chai, Jun Ho; Mayor, Julien & Kartushina, Natalia (2021). Tablet assessment of word comprehension reveals coarse word representations in 18–⁠20‐month‐old toddlers. Infancy. ISSN 1525-0008. 26(4), p. 596–616. doi: 10.1111/infa.12401. Full text in Research Archive Show summary

  The present study explores the viability of using tablets in assessing early word comprehension by means of a two‐alternative forced‐choice task. Forty‐nine 18–20‐month‐old Norwegian toddlers performed a touch‐based word recognition task, in which they were prompted to identify the labeled target out of two displayed items on a touchscreen tablet. In each trial, the distractor item was either semantically related (e.g., dog–cat) or unrelated (e.g., dog–airplane) to the target. Our results show that toddlers as young as 18 months can engage meaningfully with a tablet‐based assessment, with minimal verbal instruction and child–administrator interaction. Toddlers performed better in the semantically unrelated condition than in the related condition, suggesting that their word representations are still semantically coarse at this age. Furthermore, parental reports of comprehension, using the Norwegian version of the MacArthur–Bates Communicative Development Inventories, predicted toddlers’ performance, with parent–child agreement stronger in the semantically unrelated condition, indicating that parents declare a word to be known by their child if it is understood at a coarse representational level. This study provides among the earliest evidence that remote data collection in 18‐20 month‐old toddlers is viable, as comparable results were observed from both in‐laboratory and online administration of the touchscreen recognition task.

• Kartushina, Natalia; Rosslund, Audun & Mayor, Julien (2021). Toddlers raised in multi-dialectal families learn words better in accented speech than those raised in monodialectal families. Journal of Child Language. ISSN 0305-0009. doi: 10.1017/S0305000921000520. Full text in Research Archive Show summary

  Abstract Multi-accent environments offer rich but inconsistent language input, as words are produced differently across accents. The current study examined, in two experiments, whether multi-accent variability affects infants’ ability to learn words and whether toddlers’ prior experience with accents modulates learning. In Experiment 1, two-and-a-half-year-old Norwegian toddlers were exposed, in their kindergarten, twice per day for one week, to a child-friendly audiovisual tablet-based e-book containing four novel pseudowords. Half of the toddlers heard the story in three Norwegian accents, whereas the other half heard it in one Norwegian accent. The results revealed no differences between conditions, suggesting that multi-accent variability did not hinder toddlers’ word learning. In experiment 2, two-and-a-half-year-old Norwegian toddlers were exposed, in their homes, for one week, to the e-book featuring three Norwegian accents. The results revealed overall better learning in toddlers raised in bi-dialectal households, as compared to mono-dialectal peers – suggesting that accent exposure benefits learning in multi-accent environments.

• Bukhalenkova, Daria; Gavrilova, Margarita & Kartushina, Natalia (2021). Intuitive Theories of Parenting and the Development of Emotion Understanding in Preschoolers. Education Sciences. 11(1). doi: 10.3390/educsci11010015. Full text in Research Archive
• Bukhalenkova, Daria; Veraksa, Aleksandr; Gavrilova, Margarita & Kartushina, Natalia (2021). Psychometric Properties of the Russian-Language Version of the Early Parental Attitudes Questionnaire (EPAQ) Designed to Assess Intuitive Theories of Parenting. Educational Studies Moscow. ISSN 1814-9545. p. 227–242. doi: 10.17323/1814-9545-2021-2-227-242. Full text in Research Archive
• Veraksa, Aleksander; Bukhalenkova, Daria; Kartushina, Natalia & Oshchepkova, Ekaterina (2020). The Relationship between Executive Functions and Language Production in 5–6-Year-Old Children: Insights from Working Memory and Storytelling. Behavioral Sciences. 10(2). doi: 10.3390/bs10020052. Full text in Research Archive Show summary

  This study examined the relationship between working memory capacity and narrative abilities in 5–6-year-old children. 269 children were assessed on their visual and verbal working memory and performed in a story retelling and a story creation (based on a single picture and on a series of pictures) tasks. The stories were evaluated on their macrostructure and microstructure. The results revealed a significant relationship between both components (verbal and visual) of working memory and the global indicators of a story’s macrostructure—such as semantic completeness, semantic adequacy, programming and narrative structure—and with the indicators of a story’s microstructure, such as grammatical accuracy and number of syntagmas. Yet, this relationship was systematically stronger for verbal working memory, as compared to visual working memory, suggesting that a well-developed verbal working memory leads to lexically and grammatically more accurate language production in preschool children.

• Frank, Michael; Alcock, Katherine; Arias-Trejo, Natalia; Ascherslegen, Gisa; Baldwin, Dare & Barbu, Stephanie [Show all 56 contributors for this article] (2020). Quantifying sources of variability in infancy research using the infant-directed speech preference. Advances in Methods and Practices in Psychological Science (AMPPS). ISSN 2515-2459. 3(1), p. 24–52. doi: 10.1177/2515245919900809. Full text in Research Archive Show summary

  The field of psychology has become increasingly concerned with issues related to methodology and replicability. Infancy researchers face specific challenges related to replicability: high-powered studies are difficult to conduct, testing conditions vary across labs, and different labs have access to different infant populations, amongst other factors. Addressing these concerns, we report on a large-scale, multi-site study aimed at 1) assessing the overall replicability of a single theoretically-important phenomenon and 2) examining methodological, situational, cultural, and developmental moderators. We focus on infants’ preference for infant-directed speech (IDS) over adult-directed speech (ADS). Stimuli of mothers speaking to their infants and to an adult were created using semi-naturalistic laboratory-based audio recordings in North American English. Infants’ relative preference for IDS and ADS was assessed across 67 laboratories in North America, Europe, and Asia using the three commonly-used infant discrimination methods (head-turn preference, central fixation, and eye tracking). The overall meta-analytic effect size (Cohen’s d) was 0.35 [0.29 - 0.42], which was reliably above zero but smaller than that found in a previous meta-analysis (0.72). The IDS preference was significantly stronger in older children, in those children for whom the stimuli matched their native language and dialect, and in data from labs using the head-turn preference procedure. Together these findings replicate the infant-directed speech preference but suggest that its magnitude is modulated by development, native language experience, and testing procedure.

• Kartushina, Natalia & Martin, Clara D. (2019). Talker and Acoustic Variability in Learning to Produce Nonnative Sounds: Evidence from Articulatory Training. Language Learning. ISSN 0023-8333. 69(1), p. 71–105. doi: 10.1111/lang.12315. Full text in Research Archive
• Kartushina, Natalia & Martin, Clara D. (2019). Third-language learning affects bilinguals’ production in both their native languages: A longitudinal study of dynamic changes in L1, L2 and L3 vowel production. Journal of Phonetics. ISSN 0095-4470. 77. doi: 10.1016/j.wocn.2019.100920. Full text in Research Archive Show summary

  This study examined the impact of a study abroad (SA) English program on English and native vowel production. Basque-Spanish bilingual adolescents were assessed on their vowel production in English, Basque and Spanish before the SA program, the day after the program was completed, and four months later. The results revealed that after the SA program, participants’ English vowels were acoustically closer to English norms, revealing the effectiveness of SA programs in improving English vowel pronunciation. Yet, four months later, these benefits had faded, showing that regular input and active language use are required to maintain accurate pronunciation. SA also had effects on native production: bilingual participants showed assimilatory acoustic drift in both their languages towards the English vowel system; the extent of this drift was negatively correlated with improvements in English pronunciation. However, four months later, participants showed a ‘return’ drift towards their native norms. The results also revealed that usage frequency and switching habits played a ‘protective’ role: Frequent switching in bilinguals made the dominant native language less vulnerable to foreign-language influence. Our results suggest that factors related to the frequency and circumstances of native language use are key to authenticity in native language production.

• Kartushina, Natalia & Mayor, Julien (2019). Word knowledge in six- to nine-month-old Norwegian infants? Not without additional frequency cues. Royal Society Open Science. 6(9). doi: 10.1098/rsos.180711. Full text in Research Archive Show summary

  The past 5 years have witnessed claims that infants as young as six months of age understand the meaning of several words. To reach this conclusion, researchers presented infants with pairs of pictures from distinct semantic domains and observed longer looks at an object upon hearing its name as compared with the name of the other object. However, these gaze patterns might indicate infants' sensibility to the word frequency and/or its contextual relatedness to the object regardless of a firm semantic understanding of this word. The current study attempted, first, to replicate, in Norwegian language, the results of recent studies showing that six- to nine-month-old English-learning infants understand the meaning of many common words. Second, it assessed the robustness of a ‘comprehension’ interpretation by dissociating semantic knowledge from confounded extra-linguistic cues via the manipulation of the contingency between words and objects. Our planned analyses revealed that Norwegian six- to nine-month-old infants did not understand the meaning of the words used in the study. Our exploratory analyses showed evidence of word comprehension at eight to nine months of age—rather than from six to seven months of age for English-learning infants—suggesting that there are cross-linguistic differences in the onset of word comprehension. In addition, our study revealed that eight- to nine-month-old infants cannot rely exclusively on single extra-linguistic cues to disambiguate between two items, thus suggesting the existence of early word-object mappings. However, these mappings are weak, as infants need additional cues (such as an imbalance in frequency of word use) to reveal word recognition. Our results suggest that the very onset of word comprehension is not based on the infants' knowledge of words per se. Rather, infants use a converging set of cues to identify referents, among which frequency is a robust (pre-semantic) cue that infants exploit to guide object disambiguation and, in turn, learn new words.

• Pourquié, Marie; Lacroix, Hugues & Kartushina, Natalia (2019). Investigating vulnerabilities in grammatical processing of bilinguals: Insights from Basque-Spanish adults and children. Linguistic Approaches to Bilingualism. ISSN 1879-9264. 9(4-5), p. 600–627. doi: 10.1075/lab.17035.pou. Full text in Research Archive
• Veraksa, Aleksander; Ochepkova, Ekaterina; Bukhalenkova, Daria & Kartushina, Natalia (2019). Relationship between executive functions and speech production in senior preschool children: working memory and storytelling. Clinical Psychology and Special Education. ISSN 2304-0394. 8(3), p. 56–84. doi: 10.17759/cpse.2019080304. Full text in Research Archive
• Kartushina, Natalia (2017). Interactions between native and non-native vowels in French-Danish contact: production training study, Romance-Germanic Bilingual Phonology. Equinox Publishing. ISSN 9781781792827. p. 137–156. doi: 10.1037/e528942014-664. Full text in Research Archive

View all works in NVA

• Boskovic, Ana; Rosslund, Audun Rørvik; Mayor, Julien & Kartushina, Natalia (2026). Statistical learning and word segmentation in Norwegian infants: No evidence across dialectal variability. Full text in Research Archive
• Kartushina, Natalia; Rosslund, Audun Rørvik; Vangsnes, Øystein Alexander & Mayor, Julien (2026). Dialect exposure in infancy: Hurdle or help? New insights into language processing. Full text in Research Archive
• Bogoyavlenskaya, Alexandra; Onnis, Luca & Kartushina, Natalia (2026). Child Social Network and Lexical Development. doi: https:/psychologicalscience.confex.com/psychologicalscience/2026annual/meetingapp.cgi/Paper/61647. Full text in Research Archive Show summary

  The study investigates the relationship between infants’ social network diversity and lexical development in children aged 18, 24, and 36 months. Using parental reports and direct measure we examine how the diversity of social networks in early childhood influences expressive vocabulary size.

• Bogoyavlenskaya, Alexandra; Onnis, Luca & Kartushina, Natalia (2026). The Ecology of Human Vocal Learning: A Child Network Approach. doi: https:/bcccd.org/final-program.htm#51462abstext. Full text in Research Archive Show summary

  Vocal learning is a steppingstone in the development of language via the progressive acquisition and mastery of language-specific speech sounds from exposure to ambient speech. Children's language development is significantly influenced by their social environments, yet research primarily emphasizes the role of individual caregivers rather than broader social networks (Goldstein, King & West, 2003; Athari et al., 2021). Variability in a child's social network, such as the number of close relationships and the diversity of speakers, may impact their speech perception and production, hinting at a complex relationship between social interaction and vocal learning (Okocha et al., 2024, Casillas et al., 2020). Current evidence is inconclusive, indicating that while some studies suggest benefits from speaker variability, others show no correlation with language outcomes, highlighting the necessity for further investigations to clarify how diverse social networks contribute to infants' language acquisition (Estes & Lew-Williams, 2015; Bulgarelli & Bergelson, 2023). We hypothesize that individual differences in the social diversity of interactions of 11-month-old infants relate to their maturity of early vocalizations, i.e. proportion of canonical babbling, as measured during naturalistic parent-child play interactions. We thus predict that a larger speaker variability (different unique speakers regularly speaking to the child and in the presence of the child, weighted by their frequency of interactions) should be associated with more mature vocalizations at the same age. We recruit families with monolingual Norwegian infants. Data collection involves online parental interviews about the child's social network and audio recordings of play interactions, with analyses focusing on vocalization types and speaker diversity measured through Shannon's entropy, using mixed-effects regression models to assess the relationship between social network diversity and vocalization maturity. This study contributes to a better understanding of the role of the child social network in the emergence of human speech, and the trajectories of speech development.

• Rosslund, Audun Rørvik; Serres, Nora Rose; Kartushina, Natalia & Mayor, Julien (2025). Early language acquisition: From birth order effect to child-to-caregiver ratio. Full text in Research Archive
• Otto, Sofie; Kartushina, Natalia; Rosslund, Audun Rørvik & Mayor, Julien (2025). Parents’ attitudes and early parent-child interactions: Insights from a language-generic intervention on multilingual families. Full text in Research Archive
• Boskovic, Ana; Kartushina, Natalia; Mayor, Julien & Rosslund, Audun Rørvik (2025). The impact of dialectal variability on word segmentation in infancy: Insights from Norway. Full text in Research Archive
• Serres, Nora Rose; Mayor, Julien; Kartushina, Natalia & Rosslund, Audun Rørvik (2025). Dialectal variability shapes early language development: Evidence from mispronunciation sensitivity in 13-month-old infants. Full text in Research Archive
• Rosslund, Audun Rørvik; Kartushina, Natalia; Serres, Nora Rose & Mayor, Julien (2025). Negative sibling effects revised: When a sibling becomes a caregiver. Full text in Research Archive
• Rosslund, Audun Rørvik; Mayor, Julien & Kartushina, Natalia (2025). No evidence that Norwegian parents tailor infant-directed speech based on attributed word knowledge. Full text in Research Archive
• Kartushina, Natalia; Mayor, Julien; White, Michelle Jennifer; Gundersen, Anni Sofie Myrtveit; Onnis, Luca & Hagelund, Silje [Show all 9 contributors for this article] (2025). Reliability of acoustic measures of infant-directed speech between lab and home environments and play and reading contexts. Full text in Research Archive
• Rosslund, Audun; Mayor, Julien; Mundry, Roger; Singh, Arun Prakash; Cristia, Alejandrina & Kartushina, Natalia (2024). A longitudinal investigation of the acoustic properties of infant-directed speech from 6 to 18 months. Full text in Research Archive
• Munoz, Luis Eduardo; Rosslund, Audun; Kartushina, Natalia & Mayor, Julien (2024). Pacifier use is associated with reduced word comprehension in early childhood. Full text in Research Archive
• Rosslund, Audun; Mayor, Julien; Mundry, Roger; Singh, Arun Prakash; Cristia, Alejandrina & Kartushina, Natalia (2024). A longitudinal investigation of the acoustic properties of infant-directed speech from 6 to 18 months. Full text in Research Archive
• Rosslund, Audun; Hatlevoll, Nina Emilie Varjola; Mayor, Julien & Kartushina, Natalia (2024). Longitudinal changes in consonant production in infant-directed speech and infants’ early speech production from 6 to 12 months. Full text in Research Archive
• Rosslund, Audun; Mayor, Julien; Cristia, Alejandrina & Kartushina, Natalia (2024). Native and non-native vowel discrimination in 6-month-old Norwegian infants. Full text in Research Archive
• Munoz, Luis Eduardo; Rosslund, Audun; Kartushina, Natalia & Mayor, Julien (2024). No evidence of native sound discrimination in Norwegian 9-month-old infants using an eye-tracking habituation paradigm. Full text in Research Archive
• Singh, Arun Prakash & Kartushina, Natalia (2024). Classifying Infant Vocalizations in Audio Recordings through Transfer Learning and Image Processing Techniques. Full text in Research Archive Show summary

  The identification and classification of infants' vocalizations (into canonical vs non-canonical babbling vs adult/other) in audio recordings can play crucial role in understanding infants’ language and speech development in various learning environments. Recent research indicates that deep learning models such as convolution neural network (CNN) trained from ‘scratch’ can be utilized to accomplish various audio classification tasks including classifying infants’ vocalizations. However, to achieve high classification accuracy, models trained from scratch require large number of vocalization instances. This study addresses this limitation and examines whether pre-trained vision deep learning models, using transfer learning with spectrogram images of vocalization audio clips as input, can achieve better accuracy in classifying infant vocalizations. An open-source labelled database of infant and adult vocalization recorded in a home environment for English-speaking families (infants wore Lena vests for 12-hour periods at 3, 6, 9, and 18 months of age) was used for this task. Despite few audio clips of infant and adult vocalizations being available, the classification accuracies of various vision deep learning models, used in the current study, ranged between 64.50% to 82.77%, which is higher, as compared to previously used models when trained with same number of audio clips, i.e., between 55% and 71.42% of accuracy.

• Li, Peng; Flege, James Emil; Martin, Clara D. & Kartushina, Natalia (2023). A longitudinal perception study on the establishment of L2 categories. Full text in Research Archive
• Hatlevoll, Nina Emilie Varjola; Rosslund, Audun; Mayor, Julien & Kartushina, Natalia (2023). Voice onset time in Norwegian infant directed speech: A longitudinal study on the relationship between consonant production in parents’ IDS and infants’ babbling. Full text in Research Archive
• Li, Peng; Martin, Clara D. & Kartushina, Natalia (2023). Language dominance and code-switching shape vowel production in Basque-Spanish bilinguals. Full text in Research Archive
• Li, Peng; Flege, James Emil; Martin, Clara D. & Kartushina, Natalia (2023). Speech sound stability over time: Evidence from Norwegian vowels in spontaneous speech production. Full text in Research Archive
• Li, Peng; Martin, Clara D. & Kartushina, Natalia (2023). A comparison of Spanish and Gipuzkoa Basque vowels produced by Basque-Spanish bilinguals. Full text in Research Archive
• Li, Peng; Flege, James Emil; Martin, Clara D. & Kartushina, Natalia (2023). Regressive transfer from L2 to L1 in speech production after a study abroad program. Full text in Research Archive
• Rosslund, Audun; Hagelund, Silje; Mayor, Julien & Kartushina, Natalia (2023). Mothers’ and fathers’ infant- directed speech have similar acoustic properties, but these are not associated with direct or indirect measures of word comprehension in 8-month-old infants. Full text in Research Archive
• Rosslund, Audun; Kartushina, Natalia & Mayor, Julien (2023). Associations between shared book reading and vocabulary size are stronger among lower-SES infants. Full text in Research Archive
• Munoz, Luis Eduardo; Rosslund, Audun; Mayor, Julien & Kartushina, Natalia (2023). No evidence of native sound discrimination in Norwegian 9-month-old infants using an eye-tracking habituation paradigm. Full text in Research Archive
• Kartushina, Natalia; Onnis, Luca; Rosslund, Audun; Singh, Arun Prakash; White, Michelle Jennifer & Theimann, Ane [Show all 14 contributors for this article] (2023). Babies and kids - how do they acquire and learn multiple lects? Full text in Research Archive
• Serres, Nora Rose; Mayor, Julien & Kartushina, Natalia (2023). The role of dialect variability on mispronunciation sensitivity: An insight to infants’ early language development from a Norwegian context. Full text in Research Archive
• Singh, Arun Prakash & Kartushina, Natalia (2023). Use of transfer learning and image models to categorize infant vocalizations in audio recordings. Full text in Research Archive
• Rosslund, Audun; Mayor, Julien & Kartushina, Natalia (2022). Barns ordforråd skjøt fart når barnehagene stengte ned under pandemien. Første steg. ISSN 1504-1891. Full text in Research Archive
• Rosslund, Audun; Mayor, Julien; Óturai, Gabriella & Kartushina, Natalia (2022). Parents’ hyper pitch and vowel category compactness in infant-directed speech are associated with 18-month-old toddlers’ expressive vocabulary. Full text in Research Archive
• Rosslund, Audun; Mayor, Julien; Óturai, Gabriella & Kartushina, Natalia (2022). Parents’ hyper pitch and vowel category compactness in infant-directed speech are associated with 18-month-old toddlers’ expressive vocabulary. Full text in Research Archive
• Rosslund, Audun; Mayor, Julien; Óturai, Gabriella & Kartushina, Natalia (2022). Parents’ hyper pitch and vowel category compactness in infant-directed speech are associated with 18-month-old toddlers’ expressive vocabulary. Full text in Research Archive
• Rosslund, Audun; Mayor, Julien; Óturai, Gabriella & Kartushina, Natalia (2022). Parents’ hyper pitch and vowel category compactness in infant-directed speech are associated with 18-month-old toddlers’ expressive vocabulary. Full text in Research Archive
• Rosslund, Audun; Roepstorff, Ida; Lo, Chang Huan; Chai, Jun Ho; Mayor, Julien & Kartushina, Natalia (2022). Alignments between direct tablet-based assessment of word comprehension and parent reports depend on child’s age and word properties. Full text in Research Archive
• Munoz, Luis Eduardo; Kartushina, Natalia; Martin, Clara & Baart, Martijn (2022). Investigating the impact of production training of non-native speech sounds on perception performance using the MMN. Full text in Research Archive
• Muñoz, Luis Eduardo; Kartushina, Natalia & Mayor, Julien (2022). Sustained Pacifier Use is Associated with Smaller Vocabulary sizes at 1 and 2 Years of Age. Full text in Research Archive
• Munoz, Luis Eduardo; Kartushina, Natalia & Mayor, Julien (2022). Season-of-Birth Effects on Infant Vocabulary Size. Full text in Research Archive
• Munoz, Luis Eduardo; Kartushina, Natalia & Mayor, Julien (2022). Season-of-birth effects on infant vocabulary size. Full text in Research Archive
• Munoz, Luis Eduardo; Kartushina, Natalia & Mayor, Julien (2022). Sustained Pacifier Use is Associated with Smaller Vocabulary Sizes at 1 and 2 Years of Age. Full text in Research Archive
• Giorgio, Piazza; Martin, Clara D.; Kartushina, Natalia & Flege, Jim (2022). Comparison of Acoustic Features in Speech Production Studies Run Online and in the Lab. Full text in Research Archive
• Kartushina, Natalia; Robberstad, Silje & Mayor, Julien (2021). The Role of Parental Speech in Infant Language Development: Insights from 8-9-month-old Norwegian Infants . Full text in Research Archive
• Kartushina, Natalia; Robberstad, Silje; Munoz, Luis Eduardo & Mayor, Julien (2021). Acoustic properties of Norwegian infant-directed speech and their role in language development of 8-9-month-old infants. Full text in Research Archive
• Kartushina, Natalia; Soto, David & Martin, Clara D. (2021). Self-confidence in perception and production on non-native sounds. Full text in Research Archive
• Kartushina, Natalia & Martin, Clara D. (2021). Do improvements in production training last? Only when trained with multiple speakers. Full text in Research Archive
• Kartushina, Natalia (2021). Short- and long-term effects of L2 production training. Do improvements last? Full text in Research Archive
• Kartushina, Natalia (2021). Bridging the gap between L2 speech sound acquisition and L2 teaching. Full text in Research Archive
• Rosslund, Audun; Kartushina, Natalia; Mayor, Julien; Chai, Jun Ho & Lo, Chang Huan (2021). Tablet assessment of word comprehension reveals coarse word representations in 18-20-month-old toddlers. Full text in Research Archive
• Rosslund, Audun; Mayor, Julien; Óturai, Gabriella & Kartushina, Natalia (2021). Babytalk in Tromsø. Full text in Research Archive
• Kartushina, Natalia; Rosslund, Audun Rørvik & Mayor, Julien (2020). Toddlers raised in multi- dialectal families learn words better in accented speech than those raised in monodialectal families. Full text in Research Archive
• Kartushina, Natalia; Rosslund, Audun Rørvik & Mayor, Julien (2020). Toddlers raised in multi- dialectal families learn words better in accented speech than those raised in monodialectal families. Full text in Research Archive
• Kartushina, Natalia; Rosslund, Audun Rørvik & Mayor, Julien (2020). Toddlers raised in multi- dialectal families learn words better in accented speech than those raised in monodialectal families. Full text in Research Archive
• Rosslund, Audun; Kartushina, Natalia & Mayor, Julien (2024). The acoustic properties and role of infant-directed speech in early language development – Longitudinal and cross-sectional studies. Universitetet i Oslo. Full text in Research Archive Show summary

  How do caregivers fine-tune their speech when interacting with infants? Do these potential modulations support infants’ language development? In this dissertation, Rosslund and colleagues tackle these questions and address gaps in the scientific literature on so-called infant-directed speech (IDS). Accumulated across four preregistered studies, the dissertation provides both longitudinal and cross-sectional evidence that Norwegian parents modulate the intonational, temporal, and segmental features of their speech to infants. However, some of these acoustic modulations challenge the notion that IDS is directly tailored to facilitate language learning. This is further supported by the lack of associations between properties of parents’ IDS and infants’ language outcomes from 6 to 12 months of age. Additionally, at 18 months, infants who receive speech input with more variable vowel categories have smaller vocabularies than their peers. Yet, at the same age, parents who adapt a more exaggerated pitch height in IDS have infants with larger vocabularies. Thus, IDS might only indirectly support language development by attracting infants’ attention to the parent and speech stream, in turn bootstrapping language processing mechanisms. This dissertation contributes to the empirical evidence and theoretical debate regarding IDS by presenting analyses of a comprehensive set of acoustic properties of speech and their relationship with infants’ language outcomes, thereby providing a more explicit test of its proposed role in language development. Notably, our studies are coupled with open materials and data, inviting continued exploration and promoting scientific progress.

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