Visual statistical learning in preverbal infants at a higher likelihood of autism and its association with later social communication skills.

Visual statistical Learning (SL) allows infants to extract the statistical relationships embedded in a sequence of elements. SL plays a crucial role in language and communication competencies and has been found to be impacted in Autism Spectrum Disorder (ASD). This study aims to investigate visual SL in infants at higher likelihood of developing ASD (HL-ASD) and its predictive value on autistic-related traits at 24-36 months. At 6 months of age, SL was tested using a visual habituation task in HL-ASD and neurotypical (NT) infants. All infants were habituated to a visual sequence of shapes containing statistically predictable patterns. In the test phase, infants viewed the statistically structured, familiar sequence in alternation with a novel sequence that did not contain any statistical information. HL-ASD infants were then evaluated at 24-36 months to investigate the associations between visual SL and ASD-related traits. Our results showed that NT infants were able to learn the statistical structure embedded in the visual sequences, while HL-ASD infants showed different learning patterns. A regression analysis revealed that SL ability in 6-month-old HL-ASD infants was related to social communication and interaction abilities at 24-36 months of age. These findings indicate that early differences in learning visual statistical patterns might contribute to later social communication skills.

Infants' reorienting efficiency depends on parental autistic traits and predicts future socio-communicative behaviors.

Attentional reorienting is dysfunctional not only in children with autism spectrum disorder (ASD), but also in infants who will develop ASD, thus constituting a potential causal factor of future social interaction and communication abilities. Following the research domain criteria framework, we hypothesized that the presence of subclinical autistic traits in parents should lead to atypical infants' attentional reorienting, which in turn should impact on their future socio-communication behavior in toddlerhood. During an attentional cueing task, we measured the saccadic latencies in a large sample (total enrolled n = 89; final sample n = 71) of 8-month-old infants from the general population as a proxy for their stimulus-driven attention. Infants were grouped in a high parental traits (HPT; n = 23) or in a low parental traits (LPT; n = 48) group, according to the degree of autistic traits self-reported by their parents. Infants (n = 33) were then longitudinally followed to test their socio-communicative behaviors at 21 months. Results show a sluggish reorienting system, which was a longitudinal predictor of future socio-communicative skills at 21 months. Our combined transgenerational and longitudinal findings suggest that the early functionality of the stimulus-driven attentional network-redirecting attention from one event to another-could be directly connected to future social and communication development.

Rules generalization in children with dyslexia.

BACKGROUND: Rule learning (RL) is the ability to extract and generalize higher-order repetition-based structures. Children with Developmental Dyslexia (DD) often report difficulties in learning complex regularities in sequential stimuli, which might be due to the complexity of the rule to be learned. Learning high-order repetition-based rules represents a building block for the development of language skills. AIMS: This study investigates the ability to extract and generalize simple, repetition-based visual rules (e.g., ABA) in 8-11-year-old children without (TD) and with a diagnosis of Development Dyslexia (DD) and its relationship with language and reading skills. METHOD: Using a forced-choice paradigm, children were first exposed to a visual sequence containing a repetition-based rule (e.g., ABA) and were then asked to recognize familiar and novel rules generated by new visual elements. Standardized language and reading tests were also administered to both groups. RESULTS: The accuracy in recognizing rules was above chance for both groups, even though DD children were less accurate than TD children, suggesting a less efficient RL mechanism in the DD group. Moreover, visual RL was positively correlated with both language and reading skills. CONCLUSION: These results further confirm the crucial role of RL in the acquisition of linguistic skills and mastering reading abilities.

Differentiating early sensory profiles in toddlers at elevated likelihood of autism and association with later clinical outcome and diagnosis.

LAY ABSTRACT: Early sensory responsiveness may produce cascading effects on later development, but the relation between sensory profiles and autistic diagnosis remains unclear. In a longitudinal sample of toddlers at elevated likelihood for autism, we aimed to characterize sensory subgroups and their association with clinical outcomes later on. Three sensory subgroups were described and early sensory sensitivity plays a significant role in later development and diagnosis. This study supported the importance of examining different levels of sensory patterns to dissect the phenotypic heterogeneity in sensory processing. As sensory differences are associated with later developmental outcomes, these results may be critical when designing intervention needs and support for children at increased likelihood for neurodevelopmental disorders.

Baseline EEG in the first year of life: Preliminary insights into the development of autism spectrum disorder and language impairments.

Early identification of neurodevelopmental disorders is important to ensure a prompt and effective intervention, thus improving the later outcome. Autism spectrum disorder (ASD) and language learning impairment (LLI) are among the most common neurodevelopmental disorders, and they share overlapping symptoms. This study aims to characterize baseline electroencephalography (EEG) spectral power in 6- and 12-month-old infants at higher likelihood of developing ASD and LLI, compared to typically developing infants, and to preliminarily verify if spectral power components associated with the risk status are also linked with the later ASD or LLI diagnosis. We found risk status for ASD to be associated with reduced power in the low-frequency bands and risk status for LLI with increased power in the high-frequency bands. Interestingly, later diagnosis shared similar associations, thus supporting the potential role of EEG spectral power as a biomarker useful for understanding pathophysiology and classifying diagnostic outcomes.

Intergenerational longitudinal associations between parental reading/musical traits, infants' auditory processing, and later phonological awareness skills.

The intergenerational transmission of language/reading skills has been demonstrated by evidence reporting that parental literacy abilities contribute to the prediction of their offspring's language and reading skills. According to the "Intergenerational Multiple Deficit Model," literacy abilities of both parents are viewed as indicators of offspring's liability for literacy difficulties, since parents provide offspring with genetic and environmental endowment. Recently, studies focusing on the heritability of musical traits reached similar conclusions. The "Musical Abilities, Pleiotropy, Language, and Environment (MAPLE)" framework proposed that language/reading and musical traits share a common genetic architecture, and such shared components have an influence on the heritable neural underpinnings of basic-level skills underlying musical and language traits. Here, we investigate the intergenerational transmission of parental musical and language-related (reading) abilities on their offspring's neural response to a basic auditory stimulation (neural intermediate phenotype) and later phonological awareness skills, including in this complex association pattern the mediating effect of home environment. One-hundred and seventy-six families were involved in this study. Through self-report questionnaires we assessed parental reading abilities and musicality, as well as home literacy and musical environment. Offspring were involved in a longitudinal study: auditory processing was measured at 6 months of age by means of a Rapid Auditory Processing electrophysiological paradigm, and phonological awareness was assessed behaviorally at 5 years of age. Results reveal significant correlations between parents' reading skills and musical traits. Intergenerational associations were investigated through mediation analyses using structural equation modeling. For reading traits, the results revealed that paternal reading was indirectly associated with children's phonological awareness skills via their electrophysiological MisMatch Response at 6 months, while maternal reading was directly associated with children's phonological awareness. For musical traits, we found again that paternal musicality, rather than maternal characteristics, was associated with children's phonological phenotypes: in this case, the association was mediated by musical environment. These results provide some insight about the intergenerational pathways linking parental reading and musical traits, neural underpinnings of infants' auditory processing and later phonological awareness skills. Besides shedding light on possible intergenerational transmission mechanisms, this study may open up new perspectives for early intervention based on environmental enrichment.

Long-Lasting Effects of Changes in Daily Routine during the Pandemic-Related Lockdown on Preschoolers' Language and Emotional-Behavioral Development: A Moderation Analysis.

The quantity and quality of environmental stimuli and contexts are crucial for children's development. Following the outbreak of SARS-CoV-2 (COVID-19), restrictive measures have been implemented, constraining children's social lives and changing their daily routines. To date, there is a lack of research assessing the long-lasting impacts that these changes have had on children's language and emotional-behavioral development. In a large sample of preschoolers (N = 677), we investigated (a) the long-lasting effects of changes in family and social life and in daily activities over the first Italian nationwide COVID-19-pandemic-related lockdown upon children's linguistic and emotional-behavioral profiles and (b) how children's demographic variables and lifelong family characteristics moderated these associations within a multiple-moderator framework. Our findings showed a relationship between the time spent watching TV/playing video games and affective problems that was moderated by the number of siblings. Our findings showed that children who could be at high risk in more normal circumstances, such as only children, have been particularly harmed. Therefore, assessing the long-term effects of lockdown-related measures and how these could have been moderated by potential risk/protective factors added significant information to the existing literature.

Autism and Neurodevelopmental Disorders: The SARS-CoV-2 Pandemic Implications.

The Special Issue (SI) "Autism and Neurodevelopmental Disorders: The SARS-CoV-2 Pandemic Implications" is an interesting project that adopted a scientific point of view with important implications in clinical and practical fields [...].

Infants aged 12 months use the gender feature in determiners to anticipate upcoming words: an eye-tracking study.

We investigated online early comprehension in Italian children aged 12 and 20 months, focusing on the role of morphosyntactic features (i.e., gender) carried by determiners in facilitating comprehension and anticipating upcoming words. A naturalistic eye-tracking procedure was employed, recording looking behaviours during a classical Looking-While-Listening task. Children were presented with sentences and pictures of two objects representing nouns characterised by either the same gender (determiner was uninformative) or a different gender (determiner was informative). As expected, 20-month-old children recognised the target picture when this was named, and they were faster in the different-gender condition. Interestingly, 12-month-old infants identified the target picture only when presented with an informative determiner (different-gender condition). These results suggest that, as early as 12 months of age and with an improvement seen at 20 months of age, toddlers can extract and use determiner gender features to enhance comprehension and make predictions about upcoming words.

Synchronizing with the rhythm: Infant neural entrainment to complex musical and speech stimuli.

Neural entrainment is defined as the process whereby brain activity, and more specifically neuronal oscillations measured by EEG, synchronize with exogenous stimulus rhythms. Despite the importance that neural oscillations have assumed in recent years in the field of auditory neuroscience and speech perception, in human infants the oscillatory brain rhythms and their synchronization with complex auditory exogenous rhythms are still relatively unexplored. In the present study, we investigate infant neural entrainment to complex non-speech (musical) and speech rhythmic stimuli; we provide a developmental analysis to explore potential similarities and differences between infants' and adults' ability to entrain to the stimuli; and we analyze the associations between infants' neural entrainment measures and the concurrent level of development. 25 8-month-old infants were included in the study. Their EEG signals were recorded while they passively listened to non-speech and speech rhythmic stimuli modulated at different rates. In addition, Bayley Scales were administered to all infants to assess their cognitive, language, and social-emotional development. Neural entrainment to the incoming rhythms was measured in the form of peaks emerging from the EEG spectrum at frequencies corresponding to the rhythm envelope. Analyses of the EEG spectrum revealed clear responses above the noise floor at frequencies corresponding to the rhythm envelope, suggesting that - similarly to adults - infants at 8 months of age were capable of entraining to the incoming complex auditory rhythms. Infants' measures of neural entrainment were associated with concurrent measures of cognitive and social-emotional development.

Visual Implicit Learning Abilities in Infants at Familial Risk for Language and Learning Impairments.

The ability of infants to track transitional probabilities (Statistical Learning-SL) and to extract and generalize high-order rules (Rule Learning-RL) from sequences of items have been proposed as being pivotal for the acquisition of language and reading skills. Although there is ample evidence of specific associations between SL and RL abilities and, respectively, vocabulary and grammar skills, research exploring SL and RL as early markers of language and learning (dis)abilities is still scarce. Here we investigated the efficiency of visual SL and RL skills in typically developing (TD) seven-month-old infants and in seven-month-old infants at high risk (HR) for language learning impairment. Infants were tested in two visual-habituation tasks aimed to measure their ability to extract transitional probabilities (SL task) or high-order, repetition-based rules (RL task) from sequences of visual shapes. Post-habituation looking time preferences revealed that both TD and HR infants succeeded in learning the statistical structure (SL task), while only TD infants, but not HR infants, were able to learn and generalize the high-order rule (RL task). These findings suggest that SL and RL may contribute differently to the emergence of language learning impairment and support the hypothesis that a mechanism linked to the extraction of grammar structures may contribute to the disorder.

Atypical ERP responses to audiovisual speech integration and sensory responsiveness in infants at risk for autism spectrum disorder.

Atypical sensory responses are included in the diagnostic criteria of autism spectrum disorder (ASD). Autistic individuals perform poorly during conditions that require integration across multiple sensory modalities such as audiovisual (AV) integration. Previous research investigated neural processing of AV integration in infancy. Yet, this has never been studied in infants at higher likelihood of later ASD (HR) using neurophysiological (EEG/ERP) techniques. In this study, we investigated whether ERP measures of AV integration differentiate HR infants from low-risk (LR) infants and whether early AV integration abilities are associated with clinical measures of sensory responsiveness. At age 12 months, AV integration in HR (n = 21) and LR infants (n = 19) was characterized in a novel ERP paradigm measuring the McGurk effect, and clinical measures of sensory responsiveness were evaluated. Different brain responses over the left temporal area emerge between HR and LR infants, specifically when AV stimuli cannot be integrated into a fusible percept. Furthermore, ERP responses related to integration of AV incongruent stimuli were found to be associated with sensory responsiveness, with reduced effects of AV incongruency being associated with reduced sensory reactivity. These data suggest that early identification of AV deficits may pave the way to innovative therapeutic strategies for the autistic symptomatology. Further replications in independent cohorts are needed for generalizability of findings.

Impact of Early Rhythmic Training on Language Acquisition and Electrophysiological Functioning Underlying Auditory Processing: Feasibility and Preliminary Findings in Typically Developing Infants.

Previous evidence has shown that early auditory processing impacts later linguistic development, and targeted training implemented at early ages can enhance auditory processing skills, with better expected language development outcomes. This study focuses on typically developing infants and aims to test the feasibility and preliminary efficacy of music training based on active synchronization with complex musical rhythms on the linguistic outcomes and electrophysiological functioning underlying auditory processing. Fifteen infants participated in the training (RTr+) and were compared with two groups of infants not attending any structured activities during the same time frame (RTr-, N = 14). At pre- and post-training, expressive and receptive language skills were assessed using standardized tests, and auditory processing skills were characterized through an electrophysiological non-speech multi-feature paradigm. Results reveal that RTr+ infants showed significantly broader improvement in both expressive and receptive pre-language skills. Moreover, at post-training, they presented an electrophysiological pattern characterized by shorter latency of two peaks (N2* and P2), reflecting a neural change detection process: these shifts in latency go beyond those seen due to maturation alone. These results provide preliminary evidence on the efficacy of our training in improving early linguistic competences, and in modifying the neural underpinnings of auditory processing in infants.

Detection without further processing or processing without automatic detection? Differential ERP responses to lexical-semantic processing in toddlers at high clinical risk for autism and language disorder.

Delays in early expressive vocabulary can reflect a specific delay in language acquisition or more general impairments in social communication. The neural mechanisms underlying the (dis)ability to establish the first lexical-semantic representations remain relatively unknown. Here, we investigate the electrophysiological underpinnings of these mechanisms during the critical phase of lexical acquisition in two groups of 19-month-old toddlers at risk for neurodevelopmental disorders, i.e., children characterized by low expressive vocabulary (late talkers, N = 18) and children with early signs of Autism Spectrum Disorder (ASD, N = 18) as compared to typically developing children (N = 28), with the aim to identify similarities and specificities in lexical-semantic processing between these groups. ERPs elicited by words (either congruous or incongruous with the previous picture context) and pseudo-words are investigated within a picture-word matching paradigm. In order to further interpret ERP responses, we look at longitudinal intra-group associations with language and socio-communications skills at age 24 months. As expected, we found differences between the groups that might underlie specificities, but also similarities. On the one side, late talkers differed from the other two groups in the early component (phonological-lexical priming effect) reflecting detection of the correspondence between the heard word and the lexical representation pre-activated by the picture. On the other side, children with early symptoms of ASD differed from the other two groups in the late component (late positive component) reflecting the effortful semantic re-analysis following a violation. The functional interpretation of the two components is corroborated by significant correlations suggesting that the early component is associated with later socio-communication skills, whereas the late component is associated with linguistic skills. Results point in the direction of differential impaired mechanisms in the two populations, i.e., impaired automatic detection of incongruencies in late talkers vs. absence of high-level re-analysis of such incongruencies in children with early signs of ASD.

Effects of COVID-19 Lockdown on the Emotional and Behavioral Profiles of Preschool Italian Children with and without Familial Risk for Neurodevelopmental Disorders.

The effects of COVID-19 containment measures on the emotional and behavioral development of preschoolers are not clear. We investigated them within an ongoing longitudinal project including typically developing children (TD) and children at high familial risk for neurodevelopmental disorders (HR-NDD) who were potentially more vulnerable. The study included ninety children aged 2-6 years (TD = 48; HR-NDD = 42). Before the emergency phase (T0), all children received a clinical assessment, including the parent questionnaire Child Behavior Checklist for Ages 1.5-5 (CBCL 1.5-5). The same questionnaire was filled out again during the emergency (T1), together with an ad-hoc questionnaire investigating environmental factors characterizing the specific period. Changes in the CBCL profiles between T0 and T1 were evaluated. Overall, irrespective of familial risk, the average T-scores on specific CBCL scales at T1 were higher than at T0. Associations emerged between delta scores reflecting worsening scores on specific CBCL scales and clinical and environmental factors. Our results confirmed the negative impact of the lockdown on preschool children's emotional/behavioral profiles, and highlight the need for strategic approaches in the age range of 2-6 years, especially for more susceptible children owing to environmental factors and pre-existing emotional problems.

Dysfunctions in Infants' Statistical Learning are Related to Parental Autistic Traits.

Statistical learning refers to the ability to extract the statistical relations embedded in a sequence, and it plays a crucial role in the development of communicative and social skills that are impacted in the Autism Spectrum Disorder (ASD). Here, we investigated the relationship between infants' SL ability and autistic traits in their parents. Using a visual habituation task, we tested infant offspring of adults (non-diagnosed) who show high (HAT infants) versus low (LAT infants) autistic traits. Results demonstrated that LAT infants learned the statistical structure embedded in a visual sequence, while HAT infants failed. Moreover, infants' SL ability was related to autistic traits in their parents, further suggesting that early dysfunctions in SL might contribute to variabilities in ASD symptoms.

EEG Effective Source Projections Are More Bilaterally Symmetric in Infants Than in Adults.

Although anatomical brain hemispheric asymmetries have been clearly documented in the infant brain, findings concerning functional hemispheric specialization have been inconsistent. The present report aims to assess whether bilaterally symmetric synchronous activity between the two hemispheres is a characteristic of the infant brain. To asses cortical bilateral synchronicity, we used decomposition by independent component analysis (ICA) of high-density electroencephalographic (EEG) data collected in an auditory passive oddball paradigm. Decompositions of concatenated 64-channel EEG data epochs from each of 34 typically developing 6-month-old infants and from 18 healthy young adults participating in the same passive auditory oddball protocol were compared to characterize differences in functional brain organization between early life and adulthood. Our results show that infant EEG decompositions comprised a larger number of independent component (IC) effective source processes compatible with a cortical origin and having bilaterally near-symmetric scalp projections (13.8% of the infant data ICs presented a bilateral pattern vs. 4.3% of the adult data ICs). These IC projections could be modeled as the sum of potentials volume-conducted to the scalp from synchronous locally coherent field activities in corresponding left and right cortical source areas. To conclude, in this paradigm, source-resolved infant brain EEG exhibited more bilateral synchronicity than EEG produced by the adult brain, supporting the hypothesis that more strongly unilateral and likely more functionally specialized unihemispheric cortical field activities are concomitants of brain maturation.

Infants' Learning of Rule-Based Visual Sequences Predicts Language Outcome at 2 Years.

The ability to learn and generalize abstract rules from sensory input - i.e., Rule Learning (RL) - is seen as pivotal to language development, and specifically to the acquisition of the grammatical structure of language. Although many studies have shown that RL in infancy is operating across different perceptual domains, including vision, no studies have directly investigated the link between infants' visual RL and later language acquisition. Here, we conducted a longitudinal study to investigate whether 7-month-olds' ability to detect visual structural regularities predicts linguistic outcome at 2 years of age. At 7 months, infants were tested for their ability to extract and generalize ABB and ABA structures from sequences of visual shapes, and at 24 months their lexical and grammatical skills were assessed using the MacArthur-Bates CDI. Regression analyses showed that infants' visual RL abilities selectively predicted early grammatical abilities, but not lexical abilities. These results may provide the first evidence that RL mechanisms are involved in language acquisition, and suggest that RL abilities may act as an early neurocognitive marker for language impairments.

Paternal-but Not Maternal-Autistic Traits Predict Frontal EEG Alpha Asymmetry in Infants with Later Symptoms of Autism.

Previous research found that the parental autism phenotype is associated with child autism spectrum disorder (ASD), even if the pathway between autistic traits in parents and child ASD is still largely unknown. Several studies investigated frontal asymmetry in alpha oscillation (FAA) as an early marker for ASD. However, no study has examined the mediational effect of FAA between parental autistic traits and child ASD symptoms in the general population. We carried out a prospective study of 103 typically developing infants and measured FAA as a mediator between both maternal and paternal autistic traits and child ASD traits. We recorded infant baseline electroencephalogram (EEG) at 6 months of age. Child ASD symptoms were measured at age 24 months by the Child Behavior Checklist 1½-5 Pervasive Developmental Problems Scale, and parental autistic traits were scored by the Autism spectrum Quotient questionnaire. The mediation model showed that paternal vs. maternal autistic traits are associated with greater left FAA which, in turn, is associated with more child ASD traits with a significant indirect effect only in female infants vs. male infants. Our findings show a potential cascade of effects whereby paternal autistic traits drive EEG markers contributing to ASD risk.

Oscillatory gamma activity mediates the pathway from socioeconomic status to language acquisition in infancy.

BACKGROUND: The predictable path to child language acquisition is largely constrained by both brain maturation and environmental experience. The synchronized activity of large numbers of neurons gives rise to macroscopic brain oscillations on an electroencephalogram (EEG). It has been found that neural oscillations at rest in the gamma frequency band (25-45 Hz) are associated with development of different cognitive systems, including language. Although the etiology of language is explained by genetically driven brain maturation factors, environment plays a significant role. Specifically, candidate pathways from environment to language development include sociodemographic factors, primarily socioeconomic status (SES) which is likely to exert its effects on language development through other factors, such as parenting style. Despite these assumptions, no studies have so far examined the interrelation between brain maturation factors such as gamma frequency oscillatory activity, environmental factors such as SES, and language acquisition. AIM AND METHOD: In a longitudinal study of 84 Italian typically developing infants, we measured the power of oscillatory gamma activity as mediator between SES and language acquisition. Baseline EEG and information about SES were collected when infants were aged 6 months. Children were followed-up longitudinally to measure expressive vocabulary and Mean Length of Utterance (MLU) at 24 months. RESULTS: The mediation model showed that SES is associated with gamma power which, in turn, is associated with expressive language at age 24 months. A higher SES predicted an increase in left central gamma power which, in turn, predicted better language scores. CONCLUSIONS: These results confirm the predictive role of gamma activity oscillatory activity on later language acquisition, suggesting a specific role for these oscillatory mechanisms in language development milestones such as vocabulary development and early word combination. Furthermore, they suggest that SES differences in brain activity may be apparent at early stages of life and affect later language skills. If replicated, our findings could contribute to identifying highest-risk children and may prompt cost-effective preventive/treatment strategies.