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.

Linking vestibular, tactile, and somatosensory rhythm perception to language development in infancy.

First experiences with rhythm occur in the womb, with different rhythmic sources being available to the human fetus. Among sensory modalities, vestibular, tactile, and somatosensory perception plays a crucial role in early processing. However, a limited number of studies so far have specifically focused on VTS rhythms in language development. The present work investigated VTS rhythmic abilities and their role in language acquisition through two experiments with 45 infants (21 females, sex assigned at birth; M age = 661.6 days, SD = 192.6) with middle/high socioeconomic status. Specifically, 37 infants from the original sample completed Experiment 1, assessing VTS rhythmic abilities through a vibrotactile tool for music perception. In Experiment 2, linguistic abilities were evaluated in 40 participants from the same cohort, specifically testing phonological and prosodic processing. Discrimination abilities for rhythmic and linguistic stimuli were inferred from changes in pupil diameter to contingent visual stimuli over time, through a Tobii X-60 eye-tracker. The predictive effect of VTS rhythmic abilities on linguistic processing and the developmental changes occurring across ages were explored in the 32 infants who completed both Experiments 1 and 2 by means of generalized, additive and linear, mixed-effect models. Results are discussed in terms of cross-sensory (i.e., haptic to hearing) and cross-domain (i.e., music to language) effects of rhythm on language acquisition, with implications for typical and atypical development.

Interconnected Pathways: Postural Stability and Vocabulary Skills in Preschool-Aged Children.

Previous research has highlighted an interplay between postural abilities and linguistic skills during infancy. However, this relationship could undergo further radical transformations in other periods of development. This current study explored a plausible network of relationships among postural abilities and vocabulary skills in a substantial cohort (N = 222) of preschoolers aged between 2 and 5 years-a developmental phase critical for refining both language and motor competencies. Here, postural stability was measured in terms of balance duration and accuracy, alongside an assessment of comprehension and expressive vocabulary skills. Employing a diverse set of techniques, i.e., data and missing data visualization and multilevel regression analysis, task complexity and age emerged as crucial factors explaining our data. In addition, network analysis indicates that language production plays a central role within postural and language interdomain networks. The resulting discussion focuses on the useful implications of this study for the assessment of typical preschool development, which would benefit from tailored methodological inspections guided by developmental theories that are framed in inter-domain approaches.

The pupil collaboration: A multi-lab, multi-method analysis of goal attribution in infants.

The rise of pupillometry in infant research over the last decade is associated with a variety of methods for data preprocessing and analysis. Although pupil diameter is increasingly recognized as an alternative measure of the popular cumulative looking time approach used in many studies (Jackson & Sirois, 2022), an open question is whether the many approaches used to analyse this variable converge. To this end, we proposed a crowdsourced approach to pupillometry analysis. A dataset from 30 9-month-old infants (15 girls; Mage = 282.9 days, SD = 8.10) was provided to 7 distinct teams for analysis. The data were obtained from infants watching video sequences showing a hand, initially resting between two toys, grabbing one of them (after Woodward, 1998). After habituation, infants were shown (in random order) a sequence of four test events that varied target position and target toy. Results show that looking times reflect primarily the familiar path of the hand, regardless of target toy. Gaze data similarly show this familiarity effect of path. The pupil dilation analyses show that features of pupil baseline measures (duration and temporal location) as well as data retention variation (trial and/or participant) due to different inclusion criteria from the various analysis methods are linked to divergences in findings. Two of the seven teams found no significant findings, whereas the remaining five teams differ in the pattern of findings for main and interaction effects. The discussion proposes guidelines for best practice in the analysis of pupillometry data.

Face specific neural anticipatory activity in infants 4 and 9 months old.

The possibility of predicting the specific features of forthcoming environmental events is fundamental for our survival since it allows us to proactively regulate our behaviour, enhancing our chance of survival. This is particularly crucial for stimuli providing socially relevant information for communication and interaction, such as faces. While it has been consistently demonstrated that the human brain shows preferential and ontogenetically early face-evoked activity, it is unknown whether specialized neural routes are engaged by face-predictive activity early in life. In this study, we recorded high-density electrophysiological (ERP) activity in adults and 9- and 4-month-old infants undergoing an audio-visual paradigm purposely designed to predict the appearance of faces or objects starting from congruent auditory cues (i.e., human voice vs nonhuman sounds). Contingent negative variation or CNV was measured to investigate anticipatory activity as a reliable marker of stimulus expectancy even in the absence of explicit motor demand. The results suggest that CNV can also be reliably elicited in the youngest group of 4-month-old infants, providing further evidence that expectation-related anticipatory activity is an intrinsic, early property of the human cortex. Crucially, the findings also indicate that the predictive information provided by the cue (i.e., human voice vs nonhuman sounds) turns into the recruitment of different anticipatory neural dynamics for faces and objects.

Attentional shift within and between faces: Evidence from children with and without a diagnosis of autism spectrum disorder.

Evidence of attentional atypicalities for faces in Autism Spectrum Disorders (ASD) are far from being confirmed. Using eye-tracking technology we compared space-based and object-based attention in children with, and without, a diagnosis of ASD. By capitalizing on Egly's paradigm, we presented two objects (2 faces and their phase-scrambled equivalent) and cued a location in one of the two objects. Then, a target appeared at the same location as the cue (Valid condition), or at a different location within the same object (Same Object condition), or at a different location in another object (Different Object condition). The attentional benefit/cost in terms of time for target detection in each of the three conditions was computed. The findings revealed that target detection was always faster in the valid condition than in the invalid condition, regardless of the type of stimulus and the group of children. Thus, no difference emerged between the two groups in terms of space-based attention. Conversely the two groups differed in object-based attention. Children without a diagnosis of ASD showed attentional shift cost with phase-scrambled stimuli, but not with faces. Instead, children with a diagnosis of ASD deployed similar attentional strategies to focus on faces and their phase-scrambled version.

The unique role of novel linguistic labels on the disengagement of visual attention.

Do novel linguistic labels have privileged access to attentional resources compared to non-linguistic labels? This study explores this possibility through two experiments with a training and an attentional overlap task. Experiment 1 investigates how novel label and object-only stimuli influence resource allocation and disengagement of visual attention. Experiment 2 tests the impact of linguistic information on visual attention by comparing novel tones and labels. Because disengagement of attention is affected both by the salience of the perceptual stimulus and by the degree of familiarity with the stimulus to be disengaged from, we compared pupil size variations and saccade latency under different test conditions: (a) consistent with (i.e., identical to) the training; (b) inconsistent with the training (i.e., with an altered feature), and (c) deprived of one feature only in Experiment 1. Experiment 1 indicated a general consistency advantage (and deprived disadvantage) driven by linguistic label-object pairs compared to object-only stimuli. Experiment 2 revealed that tone-object pairs led to higher pupil dilation and longer saccade latency than linguistic label-object pairs. Our results suggest that novel linguistic labels preferentially impact the early orienting of attention.

An Integrated Perspective on Spatio-Temporal Attention and Infant Language Acquisition.

Efficiency in the early ability to switch attention toward competing visual stimuli (spatial attention) may be linked to future ability to detect rapid acoustic changes in linguistic stimuli (temporal attention). To test this hypothesis, we compared individual performances in the same cohort of Italian-learning infants in two separate tasks: (i) an overlap task, measuring disengagement efficiency for visual stimuli at 4 months (Experiment 1), and (ii) an auditory discrimination task for trochaic syllabic sequences at 7 months (Experiment 2). Our results indicate that an infant's efficiency in processing competing information in the visual field (i.e., visuospatial attention; Exp. 1) correlates with the subsequent ability to orient temporal attention toward relevant acoustic changes in the speech signal (i.e., temporal attention; Exp. 2). These results point out the involvement of domain-general attentional processes (not specific to language or the sensorial domain) playing a pivotal role in the development of early language skills in infancy.

Attentional engagement during syllable discrimination: The role of salient prosodic cues in 6- to 8-month-old infants.

Prosodic cues drive speech segmentation and guide syllable discrimination. However, less is known about the attentional mechanisms underlying an infant's ability to benefit from prosodic cues. This study investigated how 6- to 8-month-old Italian infants allocate their attention to strong vs. weak syllables after familiarization with four repeats of a single CV sequence with alternating strong and weak syllables (different syllables on each trial). In the discrimination test-phase, either the strong or the weak syllable was replaced by a pure tone matching the suprasegmental characteristics of the segmental syllable, i.e., duration, loudness and pitch, whereas the familiarized stimulus was presented as a control. By using an eye-tracker, attention deployment (fixation times) and cognitive resource allocation (pupil dilation) were measured under conditions of high and low saliency that corresponded to the strong and weak syllabic changes, respectively. Italian learning infants were found to look longer and also to show, through pupil dilation, more attention to changes in strong syllable replacement rather than weak syllable replacement, compared to the control condition. These data offer insights into the strategies used by infants to deploy their attention towards segmental units guided by salient prosodic cues, like the stress pattern of syllables, during speech segmentation.

The role of prosody in infants' preference for speech: A comparison between speech and birdsong.

Speech preferences emerge very early in infancy, pointing to a special status for speech in auditory processing and a crucial role of prosody in driving infant preferences. Recent theoretical models suggest that infant auditory perception may initially encompass a broad range of human and nonhuman vocalizations, then tune in to relevant sounds for the acquisition of species-specific communication sounds. However, little is known about sound properties eliciting infants' tuning-in to speech. To address this issue, we presented a group of 4-month-olds with segments of non-native speech (Mandarin Chinese) and birdsong, a nonhuman vocalization that shares some prosodic components with speech. A second group of infants was presented with the same segment of birdsong paired with Mandarin played in reverse. Infants showed an overall preference for birdsong over non-native speech. Moreover, infants in the Backward condition preferred birdsong over backward speech whereas infants in the Forward condition did not show clear preference. These results confirm the prominent role of prosody in early auditory processing and suggest that infants' preferences may privilege communicative vocalizations featured by certain prosodic dimensions regardless of the biological source of the sound, human or nonhuman.

Persistent primary reflexes affect motor acts: Potential implications for autism spectrum disorder.

In typical motor development progress in use of goal-directed actions and communicative gestures depends on the inhibition of several primitive reflexes, especially those that involve the hand or mouth. This study explored the relationship between the persistence of primitive reflexes that involve the hand or mouth and the motor repertoire in a sample of 12- to 17-month-old infants. Moreover, since children with Autism Spectrum Disorders (ASD) often have difficulty in performing skilled movements and show poor gesture repertoire, and since ASD represents the upper extreme of a constellation of traits that may be continuously distributed in the general population, we investigated the relationship between the persistence of primitive reflexes in the same sample of infants and the subclinical autistic traits measured in their parents. Results revealed that the persistence of the primitive reflexes correlated with motor repertoire irrespective of infant's age, and it was greater among infants whose parents had more subclinical autistic traits. Our findings suggest that the persistence of primitive reflexes might alter the developmental trajectory of future motor ability and therefore their evaluation might be an early indicator of atypical development.

Spatiotemporal neurodynamics of automatic temporal expectancy in 9-month old infants.

Anticipating events occurrence (Temporal Expectancy) is a crucial capacity for survival. Yet, there is little evidence about the presence of cortical anticipatory activity from infancy. In this study we recorded the High-density electrophysiological activity in 9 month-old infants and adults undergoing an audio-visual S1-S2 paradigm simulating a lifelike "Peekaboo" game inducing automatic temporal expectancy of smiling faces. The results indicate in the S2-preceding Contingent Negative Variation (CNV) an early electrophysiological signature of expectancy-based anticipatory cortical activity. Moreover, the progressive CNV amplitude increasing across the task suggested that implicit temporal rule learning is at the basis of expectancy building-up over time. Cortical source reconstruction suggested a common CNV generator between adults and infants in the right prefrontal cortex. The decrease in the activity of this area across the task (time-on-task effect) further implied an early, core role of this region in implicit temporal rule learning. By contrast, a time-on-task activity boost was found in the supplementary motor area (SMA) in adults and in the temporoparietal regions in infants. Altogether, our findings suggest that the capacity of the human brain to translate temporal predictions into anticipatory neural activity emerges ontogenetically early, although the underlying spatiotemporal cortical dynamics change across development.

The attentional 'zoom-lens' in 8-month-old infants.

The spatial attention mechanisms of orienting and zooming cooperate to properly select visual information from the environment and plan eye movements accordingly. Despite the fact that orienting ability has been extensively studied in infancy, the zooming mechanism--namely, the ability to distribute the attentional resources to a small or large portion of the visual field--has never been tested before. The aim of the present study was to evaluate the attentional zooming abilities of 8-month-old infants. An eye-tracker device was employed to measure the saccadic latencies (SLs) at the onset of a visual target displayed at two eccentricities. The size of the more eccentric target was adjusted in order to counteract the effect of cortical magnification. Before the target display, attentional resources were automatically focused (zoom-in) or spread out (zoom-out) by using a small or large cue, respectively. Two different cue-target intervals were also employed to measure the time course of this attentional mechanism. The results showed that infants' SLs varied as a function of the cue size. Moreover, a clear time course emerged, demonstrating that infants can rapidly adjust the attentional focus size during a pre-saccadic temporal window. These findings could serve as an early marker for neurodevelopmental disorders associated with attentional zooming dysfunction such as autism and dyslexia.

Many faces, one rule: the role of perceptual expertise in infants' sequential rule learning.

Rule learning is a mechanism that allows infants to recognize and generalize rule-like patterns, such as ABB or ABA. Although infants are better at learning rules from speech vs. non-speech, rule learning can be applied also to frequently experienced visual stimuli, suggesting that perceptual expertise with material to be learned is critical in enhancing rule learning abilities. Yet infants' rule learning has never been investigated using one of the most commonly experienced visual stimulus category available in infants' environment, i.e., faces. Here, we investigate 7-month-olds' ability to extract rule-like patterns from sequences composed of upright faces and compared their results to those of infants who viewed inverted faces, which presumably are encountered far less frequently than upright faces. Infants were habituated with face triads in either an ABA or ABB condition followed by a test phase with ABA and ABB triads composed of faces that differed from those showed during habituation. When upright faces were used, infants generalized the pattern presented during habituation to include the new face identities showed during testing, but when inverted faces were presented, infants failed to extract the rule. This finding supports the idea that perceptual expertise can modulate 7-month-olds' abilities to detect rule-like patterns.

Face Orientation and Motion Differently Affect the Deployment of Visual Attention in Newborns and 4-Month-Old Infants.

Orienting visual attention allows us to properly select relevant visual information from a noisy environment. Despite extensive investigation of the orienting of visual attention in infancy, it is unknown whether and how stimulus characteristics modulate the deployment of attention from birth to 4 months of age, a period in which the efficiency in orienting of attention improves dramatically. The aim of the present study was to compare 4-month-old infants' and newborns' ability to orient attention from central to peripheral stimuli that have the same or different attributes. In Experiment 1, all the stimuli were dynamic and the only attribute of the central and peripheral stimuli to be manipulated was face orientation. In Experiment 2, both face orientation and motion of the central and peripheral stimuli were contrasted. The number of valid trials and saccadic latency were measured at both ages. Our results demonstrated that the deployment of attention is mainly influenced by motion at birth, while it is also influenced by face orientation at 4-month of age. These findings provide insight into the development of the orienting visual attention in the first few months of life and suggest that maturation may be not the only factor that determines the developmental change in orienting visual attention from birth to 4 months.

How a face may affect object-based attention: evidence from adults and 8-month-old infants.

Object-based attention operates on perceptual objects, opening the possibility that the costs and benefits humans have to pay to move attention between-objects might be affected by the nature of the stimuli. The current study reported two experiments with adults and 8-month-old infants investigating whether object-based-attention is affected by the type of stimulus (faces vs. non-faces stimuli). Using the well-known cueing task developed by Egly et al. (1994) to study the object-based component of attention, in Experiment 1 adult participants were presented with two upright, inverted or scrambled faces and an eye-tracker measured their saccadic latencies to find a target that could appear on the same object that was just cued or on the other object that was uncued. Data showed that an object-based effect (a smaller cost to shift attention within- compared to between-objects) occurred only with scrambled face, but not with upright or inverted faces. In Experiment 2 the same task was performed with 8-month-old infants, using upright and inverted faces. Data revealed that an object-based effect emerges only for inverted faces but not for upright faces. Overall, these findings suggest that object-based attention is modulated by the type of stimulus and by the experience acquired by the viewer with different objects.

Paternal autistic traits are predictive of infants visual attention.

Since subthreshold autistic social impairments aggregate in family members, and since attentional dysfunctions appear to be one of the earliest cognitive markers of children with autism, we investigated in the general population the relationship between infants' attentional functioning and the autistic traits measured in their parents. Orienting and alerting attention systems were measured in 8-month-old infants using a spatial cueing paradigm. Results showed that only paternal autistic traits were linked to their children's: (1) attentional disengagement; (2) rapid attentional orienting and (3) alerting. Our findings suggest that an early dysfunction of orienting and alerting systems might alter the developmental trajectory of future ability in social cognition and communication.

How a hat may affect 3-month-olds' recognition of a face: an eye-tracking study.

Recent studies have shown that infants' face recognition rests on a robust face representation that is resilient to a variety of facial transformations such as rotations in depth, motion, occlusion or deprivation of inner/outer features. Here, we investigated whether 3-month-old infants' ability to represent the invariant aspects of a face is affected by the presence of an external add-on element, i.e. a hat. Using a visual habituation task, three experiments were carried out in which face recognition was investigated by manipulating the presence/absence of a hat during face encoding (i.e. habituation phase) and face recognition (i.e. test phase). An eye-tracker system was used to record the time infants spent looking at face-relevant information compared to the hat. The results showed that infants' face recognition was not affected by the presence of the external element when the type of the hat did not vary between the habituation and test phases, and when both the novel and the familiar face wore the same hat during the test phase (Experiment 1). Infants' ability to recognize the invariant aspects of a face was preserved also when the hat was absent in the habituation phase and the same hat was shown only during the test phase (Experiment 2). Conversely, when the novel face identity competed with a novel hat, the hat triggered the infants' attention, interfering with the recognition process and preventing the infants' preference for the novel face during the test phase (Experiment 3). Findings from the current study shed light on how faces and objects are processed when they are simultaneously presented in the same visual scene, contributing to an understanding of how infants respond to the multiple and composite information available in their surrounding environment.

Object-based visual attention in 8-month-old infants: evidence from an eye-tracking study.

Visual attention is one of the infant's primary tools for gathering relevant information from the environment for further processing and learning. The space-based component of visual attention in infants has been widely investigated; however, the object-based component of visual attention has received scarce interest. This scarcity is surprising, given the importance of objects in driving infants' attention and predispositions to attend to object information. Here, we investigated the object-based component of attention in 8-month-old infants. An eye tracker measured the saccade latencies to find a target that could appear in a previously cued end of 2 bars (valid targets), in the other end of the cued bar (invalid same-object targets), or in the other bar but at the same distance from the cue (invalid different-object targets). Bars were unoccluded or partly occluded; if attention is object based, it should also operate on objects that require perceptual completion. After verifying in a sample of adults (Experiment 1) that a measure of saccade latency suitably assessed space-based and object-based attention, we tested 8-month-old infants (Experiment 2) using the same procedure. The results showed that in both adults and infants, target detection was faster for valid targets than for invalid ones (space-based effect). Moreover, for both the unoccluded and partly occluded conditions, detection was faster on invalid within-object trials than on invalid between-objects trials (object-based effect). These findings demonstrate that visual objects can operate as units of attention for infants by the age of 8 months, offering implications for cognitive development.

Discrimination and ordinal judgments of temporal durations at 3 months.

This study presents the first evidence that 3-month-old infants success in a timing matching task and in an ordinal timing task, when numerical information is controlled. Three-month-old infants discriminated brief temporal durations that differed by a 1:3 ratio, relying solely on temporal information. Moreover, at 3 months of age infants were able to discriminate between monotonic and non-monotonic time-based series, when numerical and temporal information were inconsistent. These findings strengthen the hypothesis that a magnitude representational system for temporal quantities is operating very early in the ontogenetic development.