Interpersonal motor synchrony in autism: a systematic review and meta-analysis.

Introduction: Interpersonal motor synchrony (IMS) is the spontaneous, voluntary, or instructed coordination of movements between interacting partners. Throughout the life cycle, it shapes social exchanges and interplays with intra- and inter-individual characteristics that may diverge in Autism Spectrum Disorder (ASD). Here we perform a systematic review and meta-analysis to summarize the extant literature and quantify the evidence about reduced IMS in dyads including at least one participant with a diagnosis of ASD. Methods: Empirical evidence from sixteen experimental studies was systematically reviewed, encompassing spontaneous and instructed paradigms as well as a paucity of measures used to assess IMS. Of these, thirteen studies (n = 512 dyads) contributed measures of IMS with an in situ neurotypical partner (TD) for ASD and control groups, which could be used for meta-analyses. Results: Reduced synchronization in ASD-TD dyads emerged from both the systematic review and meta-analyses, although both small and large effect sizes (i.e., Hedge's g) in favor of the control group are consistent with the data (Hedge's g = .85, p < 0.001, 95% CI[.35, 1.35], 95% PI[-.89, 2.60]). Discussion: Uncertainty is discussed relative to the type of task, measures, and age range considered in each study. We further discuss that sharing similar experiences of the world might help to synchronize with one another. Future studies should not only assess whether reduced IMS is consistently observed in ASD-TD dyads and how this shapes social exchanges, but also explore whether and how ASD-ASD dyads synchronize during interpersonal exchanges.

Touch and look: The role of affective touch in promoting infants' attention towards complex visual scenes.

In a complex social environment, stimuli from different sensory modalities need to be integrated to decode communicative meanings. From very early in life, infants have to combine a multitude of sensory features with social and affective attributes. Of all senses, touch constitutes a privileged channel to carry affective-motivational meanings and foster social connection. In the present study, we investigate whether sharing sensory stimulation that varies for its affective value differentially affects infants' attention towards visual stimuli. 6 to 11-month-old infants (N = 42) were familiarized with two characters respectively matched with tactile (affective or non-affective) and auditory stimulation; then repeatedly exposed to scenes where the two characters moved towards target objects. Our results showed a main effect of stimulation (sound vs. touch) on looking times during familiarization, with longer looking times when sound is provided. During scenes presentation, a main effect of the type of touch (affective vs. non affective) emerged, with longer looking times in infants that previously experienced affective touch, suggesting that this sensory experience may critically engage the self and modulate infant attention. Overall, these findings suggest that while sound acts as attention getter, affective touch supports sustained attention towards complex visual scenes beyond the stimulation period itself.

The role of affective touch in modulating emotion processing among preschool children.

Recognizing emotional expressions is a prerequisite for understanding others' feelings and intentions, a key component of social interactions that develops throughout childhood. In multisensory social environments, touch may be crucial for emotion processing, linking external sensory information with internal affective states. The current study investigated whether affective touch facilitates recognition of emotional expressions throughout childhood. Preschool children (N = 121 3- to 6-year-olds) were presented with different tactile stimulations followed by an emotion-matching task. Results revealed that affective touch fosters the recognition of negative emotions and increases the speed of association of positive emotions, highlighting the centrality of tactile experiences for socioemotional understanding. The current research opens new perspectives on how to support emotional recognition with potential consequences for the development of social functioning.

Agency and reward across development and in autism: A free-choice paradigm.

Our ability to perform voluntary actions and make choices is shaped by the motivation from control over the resulting effects (agency) and from positive outcomes (reward). The underlying action-outcome binding mechanisms rely on sensorimotor abilities that specialise through child development and undergo different trajectories in autism. The study aimed at disentangling the role of agency and reward in driving action selection of autistic and non-autistic children and adults, who were asked to freely select one of three candies and feed the animals appearing on a tablet. The candies were associated with different probabilities of delivering a neutral vs no effect (agency task), or a positive vs neutral effect (reward task). Choices and reaction times (RT) were measured to understand whether participants preferred and were faster at selecting options with higher probability of producing a neutral vs. no effect (agency) or a positive vs. neutral effect (reward). Participants' choices and RT were not affected by agency, whereas a more frequent selection of the option with higher probability of a positive vs. neutral effect emerged across groups, thus suggesting a reward effect. Autistic participants selected less frequently the option with chance level of receiving a neutral or no effect, which could be interpreted as a sign of reduced tolerance of uncertainty. Across tasks, conditions and age groups, autistic participants presented shorter RT, which is a marker of reduced action planning and control. Future research should deepen how tolerance of uncertainty, action planning and control impact the way autistic individuals make choices in everyday life situations, potentially contributing to restricted and repetitive behaviours.

Motivation from Agency and Reward in Typical Development and Autism: Narrative Review of Behavioral and Neural Evidence.

Our ability to perform voluntary actions and make choices is shaped by the motivation from having control over the resulting effects (agency) and positive outcomes (reward). We offer an overview of distinct and common behavioral and neural signatures of agency and reward. We discuss their typical and atypical developmental trajectories, focusing on autism spectrum disorder (ASD), which is characterized by neurodiverse processes underlying action selection. We propose that reduced sensitivity to agency and reward in ASD may be related to atypical multisensory processes and motor planning, with potential for understanding restricted and repetitive behaviors. We emphasize the limitations of the existing literature, and prospects for future research. Understanding the neurocognitive processes that shape the way people with ASD select actions and perceive outcomes is essential to support not only learning, but also volition and self-determination.

Face Processing in Early Development: A Systematic Review of Behavioral Studies and Considerations in Times of COVID-19 Pandemic.

Human faces are one of the most prominent stimuli in the visual environment of young infants and convey critical information for the development of social cognition. During the COVID-19 pandemic, mask wearing has become a common practice outside the home environment. With masks covering nose and mouth regions, the facial cues available to the infant are impoverished. The impact of these changes on development is unknown but is critical to debates around mask mandates in early childhood settings. As infants grow, they increasingly interact with a broader range of familiar and unfamiliar people outside the home; in these settings, mask wearing could possibly influence social development. In order to generate hypotheses about the effects of mask wearing on infant social development, in the present work, we systematically review N = 129 studies selected based on the most recent PRISMA guidelines providing a state-of-the-art framework of behavioral studies investigating face processing in early infancy. We focused on identifying sensitive periods during which being exposed to specific facial features or to the entire face configuration has been found to be important for the development of perceptive and socio-communicative skills. For perceptive skills, infants gradually learn to analyze the eyes or the gaze direction within the context of the entire face configuration. This contributes to identity recognition as well as emotional expression discrimination. For socio-communicative skills, direct gaze and emotional facial expressions are crucial for attention engagement while eye-gaze cuing is important for joint attention. Moreover, attention to the mouth is particularly relevant for speech learning. We discuss possible implications of the exposure to masked faces for developmental needs and functions. Providing groundwork for further research, we encourage the investigation of the consequences of mask wearing for infants' perceptive and socio-communicative development, suggesting new directions within the research field.

Multimedia Interventions for Neurodiversity: Leveraging Insights from Developmental Cognitive Neuroscience to Build an Innovative Practice.

Multimedia technologies and virtual reality offer unique possibilities to manipulate sensory, motor, interpersonal, and cognitive processes contributing to atypical developmental trajectories, thus holding an explosive potential to design innovative and engaging interventions. However, there has been little progress in developing interventions that go beyond the patient's diagnosis or the fascination of technology and rather spring from a deep understanding of the specific neuropsychological processes to be nurtured in individuals. This perspective paper outlines how recent insights from developmental cognitive neuroscience can be leveraged to promote children's multidimensional development and highlight future directions and challenges for innovating both research and clinical practice. Finally, we focus on some practical examples of multimedia and virtual reality activities we have designed to stimulate bodily-self experiences, which are crucial for building up a coherent sense of self and lay the foundation for interacting with the external world. Atypical bodily self is an early marker of heterogeneous neurodevelopmental conditions (such as autism spectrum disorders) and seems to be under-targeted in research and clinical approaches.

Psychophysiological and Visual Behavioral Responses to Faces Associated with Affective and Non-affective Touch in Four-month-old Infants.

Affective touch (gentle, caress-like touch) carries a rewarding meaning, which may represent a neurophysiological foundation for the development of social interactions from the earliest stages of life. Developmental studies have shown evidence of infants' sensitivity to affective touch as reflected by a decrease in heart rate and activation of the insular cortex. Moreover, affective touch has been shown to regulate infants' emotional state, reinforce eye contact and facilitate learning of facial information, suggesting that affective touch may promote social functioning from the earliest stages of development. The present study aims to investigate the role of affective touch in enhancing engagement with social stimuli, exploring sustained attention and cardiac responses to faces as signatures of the underlying psychophysiological mechanism. Four-months-old infants (N = 40) were repeatedly presented with a female face paired with touch (hand stroking vs tapping with a brush in two different blocks) alternating with a face presented without tactile stimulation (familiarization phase), followed by a visual preference test between the two faces. Our results revealed an attenuated cardiac response in the affective compared to the non-affective condition during the familiarization phase. During the test phase infants looked longer at both the faces presented in the affective touch condition, compared to the faces in the non-affective condition. These findings suggest that affective touch might promote engagement in social interactions by facilitating physiological state regulation during processing of multisensory social information.