Neonatal imitation and its sensorimotor mechanism

In the present chapter, we propose that aspects of early social development—sensorimotor matching skills, social motivation, and temperament—may explain variability in neonatal imitation. We suggest that the presence of an action-perception mechanism at birth can be better understood by taking into account the complex interactions occurring during development between infants' social competences, in part a cause and consequence of their sensorimotor skills, and the effects of different experiences and environmental inputs on individual differences already present from birth (e.g., social interest temperament). We also present some findings and propose future directions aimed at testing these possibilities by examining individual differences related to imitative skill

Neonatal imitation predicts how infants engage with faces

In human infants, neonatal imitation and preferences for eyes are both associated with later social and communicative skills, yet the relationship between these abilities remains unexplored. Here we investigated whether neonatal imitation predicts facial viewing patterns in infant rhesus macaques. We first assessed infant macaques for lipsmacking (a core affiliative gesture) and tongue protrusion imitation in the first week of life. When infants were 10–28 days old, we presented them with an animated macaque avatar displaying a still face followed by lipsmacking or tongue protrusion movements. Using eye tracking technology, we found that macaque infants generally looked equally at the eyes and mouth during gesture presentation, but only lipsmacking-imitators showed significantly more looking at the eyes of the neutral still face. These results suggest that neonatal imitation performance may be an early measure of social attention biases and might potentially facilitate the identification of infants at risk for atypical social development

Visual preferences for direct-gaze faces in infant macaques (Macaca mulatta ) with limited face exposure

From birth, human and nonhuman primates attend more to faces with direct gaze compared with averted gaze, and previous studies report that attention to the eyes is linked to the emergence of later social skills. Here, we explored whether early experiences influence attraction to eye contact in infant macaques by examining their attention to face pairs varying in their gaze direction across the first 13 weeks of life. Infants raised by human caretakers had limited conspecific interactions (nursery‐reared; N = 16) and were compared to infants raised in rich social environments (mother‐reared; N = 20). Both groups looked longer to faces and the eyes of direct compared to averted‐gaze faces. Looking to all faces and eyes also increased with age. Nursery‐reared infants did not display age‐associated increases in attention to direct‐gaze faces specifically, suggesting that, while there may be an initial preference for direct‐gaze faces from birth, social experiences may support its early development

Neonatal imitation and early social experience predict gaze following abilities in infant monkeys

Individuals vary in their social skills and motivation, the causes of which remain largely unknown. Here we investigated whether an individual’s propensity to interact with others measured within days after birth, and differences in infants’ early social environment, may predict a later social skill. Specifically, we tested whether neonatal imitation—newborns’ capacity to match modelled actions—and social experience in the first months of life predict gaze following (directing attention to locations where others look), in infant macaques (Macaca mulatta; n = 119). Facial gesture imitation in the first week of life predicted gaze following at 7 months of age. Imitators were better at gaze following than non-imitators, suggesting neonatal imitation may be an early marker predicting socio-cognitive functioning. In addition, infants with rich social environments outperformed infants with less socialization, suggesting early social experiences also support the development of infants’ gaze following competence. The present study offers compelling evidence that an individual difference present from birth predicts a functional social cognitive skill in later infancy. In addition, this foundational skill—gaze following—is plastic, and can be improved through social interactions, providing infants with a strong foundation for later social interaction and learning

Lipsmacking imitation skill in newborn macaques is predictive of social partner discrimination

Newborn rhesus macaques imitate facial gestures even after a delay, revealing the flexible nature of their early communicative exchanges. In the present study we examined whether newborn macaques are also sensitive to the identities of the social partners with whom they are interacting. We measured infant monkeys’ (n = 90) lipsmacking and tongue protrusion gestures in a face-to-face interaction task with a human experimenter in the first week of life. After a one minute delay, the same person who previously presented gestures or a different person returned and presented a still face to infants. We had two primary predictions: (1) infants would demonstrate higher rates of overall gesturing, and especially lipsmacking—an affiliative gesture—to a familiar person, compared to a novel person, and (2) infants’ imitative skills would positively correlate with gestures to familiar, but not unfamiliar, social partners, as both abilities may reflect a strong general social interest. We found that overall infants did not produce more gestures or more lipsmacking when approached by a familiar person compared to a novel person; however, we did find individual differences in infants’ social responsiveness: lipsmacking imitation was positively correlated with lipsmacking during the return period when the person was the same (p = .025), but not when the person was novel (p = .44). These findings are consistent with the notion that imitative skill is reflective of infants’ more general interest in social interactions

Corticosterone enhances CSD susceptibility via glucocorticoid receptor activation in familial hemiplegic migraine 1 Cacna1a knock-in mice

Paroxysmal Cerebral Disorder

Face detection and the development of own-species bias in infant macaques

In visually complex environments, numerous items compete for attention. Infants may exhibit attentional efficiency—privileged detection, attention capture and holding—for face-like stimuli. However, it remains unknown when these biases develop and what role, if any, experience plays in this emerging skill. Here, nursery-reared infant macaques’ (Macaca mulatta; n = 10) attention to faces in 10-item arrays of non-faces was measured using eye tracking. With limited face experience, 3-week-old monkeys were more likely to detect faces and looked longer at faces compared to non-faces, suggesting a robust face detection system. By 3 months, after peer exposure, infants looked faster to conspecific faces, but not heterospecific faces, suggesting an own-species bias in face attention capture, consistent with perceptual attunement

Experience-independent sex differences in newborn macaques: females are more social than males

Human females exhibit greater social interest and skills relative to males, appearing in infancy, suggesting biological roots; however, male and female infants may be treated differently, potentially causing or amplifying sex differences. Here, we tested whether sex differences in social motivation emerge in infant monkeys (n = 48) reared in a controlled postnatal environment. Compared to males, females at 2–3 weeks looked more at conspecifics’ faces (d = 0.65), especially the eyes (d = 1.09), and at 4–5 weeks exhibited more affiliative behaviors (d = 0.64), including gesturing, looking, and proximity to familiar and unfamiliar human caretakers. In sum, converging evidence from humans and monkeys suggests that female infants are more social than males in the first weeks of life, and that such differences may arise independent of postnatal experience. Individual differences in social interest have wide-ranging developmental consequences, impacting infants’ social interaction quality and opportunities for learning. Understanding the evolution of sex differences and their developmental emergence is necessary to best support infants with varying levels of sociality

Early social experience affects neural activity to affiliative facial gestures in newborn nonhuman primates

A fundamental issue in cognitive neuroscience is how the brain encodes the actions and intentions of others. The discovery of an action-production-perception mechanism underpinning such a capacity advanced our knowledge of how these processes occur; however, no study has examined how the early postnatal environment may shape action-production-perception. Here, we examined the effects of social experience on action-production-perception in 3-day-old rhesus macaques that were raised either with or without their biological mothers. We measured the neonatal imitation skills and brain electrical activity responses, while infants produced and observed facial gestures. We hypothesized that early social experiences may shape brain activity, as assessed via electroencephalogram suppression in the α band (5-7 Hz in infants, known as the mu rhythm) during action observation, and lead to more proficient imitation skills. Consistent with this hypothesis, the infants reared by their mothers were more likely to imitate lipsmacking (LS) - a natural, affiliative gesture - and exhibited greater mu rhythm desynchronization while viewing LS gestures than the nursery-reared infants. These effects were not found in response to tongue protrusion, a meaningless gesture, or a nonsocial control. These data suggest that socially enriched early experiences in the first days after birth increase brain sensitivity to socially relevant actions

A double-blind, randomized, multicenter, Italian study of frovatriptan versus rizatriptan for the acute treatment of migraine

The objective of this study was to assess patient satisfaction with acute treatment of migraine with frovatriptan or rizatriptan by preference questionnaire. 148 subjects with a history of migraine with or without aura (IHS 2004 criteria), with at least one migraine attack per month in the preceding 6 months, were enrolled and randomized to frovatriptan 2.5 mg or rizatriptan 10 mg treating 1–3 attacks. The study had a multicenter, randomized, double-blind, cross-over design, with treatment periods lasting <3 months. At the end of the study, patients assigned preference to one of the treatments using a questionnaire with a score from 0 to 5 (primary endpoint). Secondary endpoints were pain-free and pain relief episodes at 2 h, and recurrent and sustained pain-free episodes within 48 h. 104 of the 125 patients (83%, intention-to-treat population) expressed a preference for a triptan. The average preference score was not significantly different between frovatriptan (2.9 ± 1.3) and rizatriptan (3.2 ± 1.1). The rates of pain-free (33% frovatriptan vs. 39% rizatriptan) and pain relief (55 vs. 62%) episodes at 2 h were not significantly different between the two treatments. The rate of recurrent episodes was significantly (p < 0.001) lower under frovatriptan (21 vs. 43% rizatriptan). No significant differences were observed in sustained pain-free episodes (26% frovatriptan vs. 22% rizatriptan). The number of patients with adverse events was not significantly different between rizatriptan (34) and frovatriptan (25, p = NS). The results suggest that frovatriptan has a similar efficacy to rizatriptan, but a more prolonged duration of action