Social communication and restricted, repetitive behavior as assessed with a diagnostic tool for autism (ADOS-2) in women with anorexia nervosa.

OBJECTIVE: In anorexia nervosa (AN), the traits of autism spectrum disorder (ASD) are associated with poor outcomes. However, the subtle nature of these characteristics remains poorly understood. We investigated the in-depth patterns of ASD traits using Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) in women with AN. METHODS: Of 28 women with ICD-10 AN, 16 (age 19-30 years) participated in the ADOS-2, a video-recorded, semistructured diagnostic assessment for social communication and interaction and restricted, repetitive behaviors and interests related to ASD. None of the participants had previously been diagnosed with ASD. Other measurements included the Eating Disorder Examination Questionnaire and the Wechsler Abbreviated Scale of Intelligence-IV. RESULTS: Five individuals (18% of all, 31% of those assessed) scored above the cutoff for autism in ADOS-2. They had challenges in social communication and interaction, manifesting as sustained difficulties in social relationships and deficits in conversation skills. Few described being frequently misunderstood by others, including in the eating disorder treatment settings. Three individuals showed prominent restricted and repetitive behaviors such as ritual seeking, eating-related routines, sensory sensitivity related to food texture and selective eating, and intense interest in specific topics. The mean duration of AN in women above the cutoff was twice as long compared with those below (12.3 vs. 6.2 years). DISCUSSION: The ASD-related characteristics and behavior appear to contribute to the manifestation and duration of AN in a subgroup of women. Among these women, the traits of ASD appear to be mixed with eating disorder symptoms, which should be taken into account in the treatment.

Genetic background to attention deficit and hyperactivity disorder and attention deficit and hyperactivity disorder symptoms at the age of 5 years: the role of sleep duration.

STUDY OBJECTIVES: We studied the associations between polygenic risk score (PRS) for attention deficit and hyperactivity disorder (ADHD) and (1) ADHD symptoms in 5-year-old children, (2) sleep duration throughout childhood, and (3) the interaction between PRS for ADHD and short sleep duration relative to ADHD symptoms at 5 years. METHODS: This study is based on the population-based CHILD-SLEEP birth cohort (N = 1420 children). PRS was used to quantitate the genetic risk for ADHD. Parent-reported ADHD symptoms at 5 years were obtained from 714 children, using the Strengths and Difficulties Questionnaire (SDQ) and the Five-to-Fifteen (FTF). Our primary outcomes were SDQ-hyperactivity and FTF-ADHD total scores. Parent-reported sleep duration was measured at 3, 8, 18, 24 months, and 5 years in the whole sample and actigraphy-based sleep duration at 2 and 24 months in a subsample. RESULTS: PRS for ADHD associated with SDQ-hyperactivity (ß = 0.214, p = .012) and FTF-ADHD total (ß = 0.639, p = .011), and FTF-inattention and hyperactivity subscale scores (ß = 0.315, p = .017 and ß = 0.324, p = .030), but not with sleep duration at any time point. Significant interactions were found between high PRS for ADHD and parent-reported short sleep throughout childhood in FTF-ADHD total score (F = 4.28, p = .039) and FTF-inattention subscale (F = 4.66, p = .031). We did not find any significant interaction between high PRS for ADHD and actigraphy-based short sleep. CONCLUSIONS: Parent-reported short sleep moderates the association between genetic risk of ADHD and ADHD symptoms in early childhood in the general population, so that children with short sleep, in combination with high genetic risk for ADHD, could be at highest risk for ADHD symptoms.

Polygenic risk for neuroticism is associated with externalizing symptoms in 2-year-old boys.

Recent advances in genome-wide association studies have enabled the estimation of genetic risk of complex traits, including neuroticism, with polygenic risk scores (PRS). Neuroticism PRS has been associated with psychiatric disorders and symptoms in adults, but studies in children are scarce. We studied whether neuroticism PRS, and its subscales, worry PRS and depressive affect PRS, were associated with externalizing and internalizing symptoms in 2-year-olds. We also examined parental neuroticism PRSs' association with children's externalizing and internalizing symptoms and whether parental depressive symptoms mediated the effect. Participants from two Finnish birth cohorts, CHILD-SLEEP and FinnBrain Birth Cohort Study, who had DNA and data on Brief Infant-Toddler Social and Emotional Assessment (BITSEA) available were included in the study (N = 806 and N = 987, respectively). PRSs were calculated based on GWAS data from UK Biobank. Child's neuroticism PRS, and its subscale worry PRS, were positively associated with externalizing symptoms in 2-year-old boys, but not in girls. Mother's depressive symptoms mediated the association between maternal neuroticism PRS and externalizing and internalizing symptoms in boys, but not in girls. Our results suggest that neuroticism PRS, and its subscale worry PRS, are associated with externalizing symptoms in already as young as 2-year-old boys, and, that subclinical symptoms of maternal depression that are based on genetic disposition, have an effect on boy's internalizing and externalizing symptoms. As we did not find any associations in girls, our study supports the suggestion that girls and boys may differ in how genetic and environmental factors contribute to their development.

Neural specialization to human faces at the age of 7 months.

Sensitivity to human faces has been suggested to be an early emerging capacity that promotes social interaction. However, the developmental processes that lead to cortical specialization to faces has remained unclear. The current study investigated both cortical sensitivity and categorical specificity through event-related potentials (ERPs) previously implicated in face processing in 7-month-old infants (N290) and adults (N170). Using a category-specific repetition/adaptation paradigm, cortical specificity to human faces, or control stimuli (cat faces), was operationalized as changes in ERP amplitude between conditions where a face probe was alternated with categorically similar or dissimilar adaptors. In adults, increased N170 for human vs. cat faces and category-specific release from adaptation for face probes alternated with cat adaptors was found. In infants, a larger N290 was found for cat vs. human probes. Category-specific repetition effects were also found in infant N290 and the P1-N290 peak-to-peak response where latter indicated category-specific release from adaptation for human face probes resembling that found in adults. The results suggest cortical specificity to human faces during the first year of life. Encoding of unfamiliar cat stimuli might explain N290 amplification found in infants.

Signaled night awakening and its association with social information processing and socio-emotional development across the first two years.

STUDY OBJECTIVES: Night awakening is common in infancy, and some infants continue to have signaled night awakenings throughout early childhood. However, the influence of signaled night awakening on children's social development is less explored. In the present study, longitudinal associations between signaled night awakening, social information processing, and socio-emotional development were measured within the CHILD-SLEEP birth cohort in two groups formed based on parent-reported night awakenings. METHODS: At 8 months, there were 77 infants in the waking group (≥3 awakenings) and 69 infants in the nonwaking group (≤1 awakening). At 8 and 24 months, social information processing was measured as children's attention to neutral and emotional faces, and at 24 months, parent-reported socio-emotional behavior was measured with the Brief Infant-Toddler Social and Emotional Assessment (BITSEA) questionnaire. RESULTS: The two groups showed different patterns of attention to emotional faces. The waking group had a more pronounced attentional bias to fearful versus happy faces, whereas in the nonwaking group, attention to fearful and happy faces did not differ. In addition, at 24 months, the waking group had more dysregulation problems and lower social competence than the nonwaking group, but no clear differences in internalizing or externalizing problems were found. CONCLUSIONS: Our results contribute to the literature by showing that during the first 2 years of life, signaled night awakening is associated with social information processing and socio-emotional behavior.

Exposure to electronic media was negatively associated with speech and language development at 18 and 24 months.

AIM: This study evaluated early speech and language development at 18 and 24 months, and associated factors, based on parental reports. METHOD: We followed up the CHILD-SLEEP birth cohort of 1667 Finnish-speaking families, who were randomly recruited in 2011-2013 during routine visits to maternity clinics in the Pirkanmaa Hospital District of Finland. The women were approximately 32 weeks' pregnant at enrolment. Parents reported the size of their child's expressive vocabulary, word combinations, intelligibility, finger-pointing and adherence to instructions. A subsample was studied using the Expressive Language subscale of the Bayley Scales of Infant and Toddler Development, Third Edition. RESULTS: The children's vocabulary was smaller than previously reported. At 18 months of age, 68.8% of the 997 children had a vocabulary of 20 words or less and 35.7% used about five words at most. At 24 months, 32.4% of the 822 children had a vocabulary of 50 words or less and 18.4% used about 20 words at most. Longer child and parental exposure to electronic media was negatively associated with the size of the child's expressive vocabulary. CONCLUSION: Vocabulary size at 18 and 24 months was smaller than previously reported and negatively associated with exposure to electronic media.

The Effects of Genetic Background for Diurnal Preference on Sleep Development in Early Childhood.

PURPOSE: No previous research has examined the impact of the genetic background of diurnal preference on children´s sleep. Here, we examined the effects of genetic risk score for the liability of diurnal preference on sleep development in early childhood in two population-based cohorts from Finland. PARTICIPANTS AND METHODS: The primary sample (CHILD-SLEEP, CS) comprised 1420 infants (695 girls), and the replication sample (FinnBrain, FB; 962 girls) 2063 infants. Parent-reported sleep duration, sleep-onset latency and bedtime were assessed at three, eight, 18 and 24 months in CS, and at six, 12 and 24 months in FB. Actigraphy-based sleep latency and efficiency were measured in CS in 365 infants at eight months (168 girls), and in 197 infants at 24 months (82 girls). Mean standard scores for each sleep domain were calculated in both samples. Polygenic risk scores (PRS) were used to quantitate the genetic risk for eveningness (PRSBestFit) and morningness (PRS10kBest). RESULTS: PRSBestFit associated with longer sleep-onset latency and later bedtime, and PRS10kBest related to shorter sleep-onset latency in CS. The link between genetic risk for diurnal preference and sleep-onset latency was replicated in FB, and meta-analysis resulted in associations (P<0.0005) with both PRS-values (PRSBestFit: Z=3.55; and PRS10kBest: Z=-3.68). Finally, PRSBestFit was related to actigraphy-based lower sleep efficiency and longer sleep latency at eight months. CONCLUSION: Genetic liability to diurnal preference for eveningness relates to longer sleep-onset during the first two years of life, and to objectively measured lowered sleep efficiency. These findings enhance our understanding on the biological factors affecting sleep development, and contribute to clarify the physiological sleep architecture in early childhood.

Prenatal and Postnatal Predictive Factors for Children's Inattentive and Hyperactive Symptoms at 5 Years of Age: The Role of Early Family-related Factors.

We examined several parent-reported prenatal and postnatal factors as potential risk factors for attention-deficit and hyperactivity disorder (ADHD) symptomatology in 5-year-old children. Our study is based on the CHILD-SLEEP birth cohort. Several parental questionnaires were collected prenatally (32nd pregnancy week) and postnatally (i.e. child aged 3, 8, and 24 months and at 5 years). At 5 years of age, ADHD symptoms were assessed using questionnaires. Our main results showed that being a boy, parental depressive symptoms, more negative family atmosphere or a child's shorter sleep duration, and maternal authoritarian parenting style predicted inattentive/hyperactive symptoms. Maternal and paternal authoritative parenting style predicted less inattentive/hyperactive symptoms. Children with several risk factors together had the highest risk for inattentive/hyperactive symptoms. Our findings emphasise the need for early screening and treatment of parental mental health, and early evidence-based targeted parental support, to enable early intervention in those children at a risk of developing ADHD.

Maternal stress or sleep during pregnancy are not reflected on telomere length of newborns.

Telomeres play an important role in maintaining chromosomal integrity. With each cell division, telomeres are shortened and leukocyte telomere length (LTL) has therefore been considered a marker for biological age. LTL is associated with various lifetime stressors and health-related outcomes. Transgenerational effects have been implicated in newborns, with maternal stress, depression, and anxiety predicting shorter telomere length at birth, possibly reflecting the intrauterine growth environment. Previous studies, with relatively small sample sizes, have reported an effect of maternal stress, BMI, and depression during pregnancy on the LTL of newborns. Here, we attempted to replicate previous findings on prenatal stress and newborn LTL in a sample of 1405 infants using a qPCR-based method. In addition, previous research has been expanded by studying the relationship between maternal sleep quality and LTL. Maternal prenatal stress, anxiety, depression, BMI, and self-reported sleep quality were evaluated with self-reported questionnaires. Despite sufficient power to detect similar or even considerably smaller effects than those previously reported in the literature, we were unable to replicate the previous correlation between maternal stress, anxiety, depression, or sleep with LTL. We discuss several possible reasons for the discrepancies between our findings and those previously described.

Social competence group intervention (SOCO) for children with autism spectrum disorder: A pilot study.

This study aimed to describe concept of social competence as a theoretical background for social skills group intervention for children with autism spectrum disorder (ASD). A model of social competence comprised of three components: social skills, social performance, and social adjustment. We also examined the feasibility and preliminary efficacy of the manualized Social Competence group intervention for children with autism spectrum disorder (SOCO) using a variety of outcome measures. The nine-month intervention included children groups, parental support groups and co-operation with teachers. A pilot study involved 23 children aged 7 to 12 years (n = 16 intervention, n = 7 control) and intervention outcomes were measured with questionnaires for parents and teachers, neuropsychological tests, and observations. The parents of the intervention group reported improvements in social skills and social adjustment, whereas the teachers reported increases in social performance. Findings also indicated that affect recognition skills, social overtures, and reactions to peers were improved in the intervention group. Although the evidence of the pilot study should be considered as preliminary, it gives some indication of the feasibility of the SOCO group intervention and supports the usability of the theoretical background and approach for multiple outcome measures.

Slow-wave activity and sigma activities are associated with psychomotor development at 8 months of age.

STUDY OBJECTIVES: The electrophysiological properties of non-rapid eye movement sleep (NREM) EEG are homeostatically modulated on global and local use-dependent levels. Furthermore, the local NREM quality reflects age-dependent brain maturation and individual, age-independent, and psychomotor potential. Cortical maturation and its electrophysiological marker, Slow-wave activity (SWA), as well as sleep spindles are known to change in topography and quality during the early years of life, but their associations with psychomotor development in infants are unknown. Therefore, we aimed to evaluate the local properties of SWA and spindles (sigma power) and ascertain whether they correlate with psychomotor development in 8-month-old infants. METHODS: Ambulatory polysomnographies were recorded in 56 infants at 8 months of age to calculate the local SWA and sigma powers. The associations between the SWA and sigma powers and psychomotor development (Bayley-III) were examined in 36 of these infants. RESULTS: In both hemispheres, the highest SWA and sigma powers were found occipitally and centrally, respectively, with higher powers in the right hemisphere than in the left. The Bayley-III correlated with local SWA and sigma powers: the occipital SWA and centro-occipital sigma correlated with cognitive scales, and the frontal and occipital SWA and centro-occipital sigma correlated with language and fine motor scales. Most of the correlations were unilateral. CONCLUSIONS: In 8-month-old infants, the NREM sleep quality shows local differences that are mostly attributable to the topical phase of brain maturation. The local NREM parameters correlate with psychomotor development.

Parent-reported early sleep problems and internalising, externalising and dysregulation symptoms in toddlers.

BACKGROUND: The concurrence of sleep and socio-emotional development in children is well accepted. However, the predictive role of sleep problems in infancy and the development of emotional and behavioural problems later in childhood remain still unclear. Therefore, in this study we examined the associations between sleep problems in early childhood and internalising, externalising and dysregulation symptoms in toddlers. METHODS: 1679 families entered the study during pregnancy and 936 children participated at 24 months. Parent-reported sleep duration, sleep-onset latency, night wakings, proportion of daytime sleep and bedtime at 3, 8, 18 and 24 months were assessed with two sleep questionnaires. Externalising, internalising and dysregulation problems at 24 months were examined with the Brief Infant-Toddler Social and Emotional Assessment. RESULTS: Short sleep duration at 3 and 8 months, more night wakings at 3, 8, 18 and 24 months and greater proportion of daytime sleep at 24 months were associated with internalising symptoms. Shorter sleep duration at 8, 18 and 24 months and longer sleep-onset latency and more night wakings at all time points, in addition to earlier bedtime at 8 months and greater proportion of daytime sleep at 24 months, were related to dysregulation. Finally, more night wakings at 3 and 24 months, and longer sleep-onset latency at 24 months were associated with externalising problems. CONCLUSION: Shorter sleep and poorer sleep quality in infancy were prospectively related to emotional and behavioural symptoms in toddlers, and these associations were strongest for internalising and dysregulation symptoms. This study contributes to the recent research on the role of early sleep problems in socio-emotional development, suggesting that shorter sleep duration, longer sleep-onset latency and higher waking frequency are related to internalising, externalising and dysregulation symptoms in toddlers, and thus it might be beneficial to provide early interventions for those infants reporting these sleep problems.

Normal sleep development in infants: findings from two large birth cohorts.

OBJECTIVE: Sleep difficulties are highly prevalent and often persistent in young children, but sometimes parents are worried about sleep symptoms that belong to the normative range rather than to actual disturbances. Therefore, the aim of this study was to describe the normative development of sleep at the ages of 3, 6, 8, 12, 18 and 24 months in healthy children. METHODS: The present study is based on two birth cohorts that comprise representative samples of families recruited systematically during pregnancy. In the CHILD-SLEEP cohort, the sample sizes were 1427 at three, 1301 at eight, 1163 at 18, and 950 at 24 months. In the Finnbrain cohort, the sample sizes were 2002 at six months and 1693 at 12 months. Healthy term-born children were eligible for this study. To assess the infants' sleep duration and sleep quality, the Brief Infant Sleep Questionnaire was used in both cohorts and additionally the Infant Sleep Questionnaire in the CHILD-SLEEP cohort. The distributions of the study variables were reported using standard parameters. RESULTS: We found that sleep quality is highly variable particularly during the first two years of life, but this variability decreased markedly towards the second year. First, sleep latency decreased by the age of six months, while night-time sleep began to consolidate during the second year. However, parent-reported sleeping problems were common during the entire study period. CONCLUSION: As many families struggle with infants' sleeping problems, the reference values reported in this article can be valuable tools in various clinical settings to define clinically significant deviances in the sleep development and to identify individuals benefitting from counselling and clinical interventions.

Maternal and paternal depressive symptoms and children's emotional problems at the age of 2 and 5 years: a longitudinal study.

BACKGROUND: Maternal and paternal depressive symptoms are related to children's emotional problems, but their combined effect remains unclear. Here, we constructed four parental longitudinal depressive symptom trajectory groups and studied their associations with children's emotional problems at the age of 2 and 5 years. METHODS: We did an assessment of maternal and paternal depressive symptoms (gestational week 32, as well as 3, 8 and 24 months postnatally) and children's emotional problems at ages two (N = 939) and five (N = 700) in the CHILD-SLEEP cohort. Three separate maternal and paternal depressive symptom trajectories based on latent profile analysis were combined to form four parental depressive symptom trajectory groups. We compared groups with a general linear model, with children's emotional (total, internalizing and externalizing) - problem scores serving as the dependent variables. RESULTS: At both ages, combined parental depressive symptom trajectories were associated with children's emotional problems: effect sizes were medium for total and small for other domains. According to post hoc comparisons, children whose mothers or both parents had persistent depressive symptoms had significantly more total, externalizing and internalizing problems than did children who had neither parent nor only the father showing depressive symptoms. A higher (and persistent) level of maternal depressive symptoms was related to a higher level of these children's emotional problems, a pattern not evident with paternal depressive symptoms. In all analyses, the interaction effect was nonsignificant between parental trajectories and child gender. CONCLUSIONS: Findings suggest that an absence of depressive symptoms in their fathers cannot compensate for the adverse effects of maternal depressive symptoms upon their children. Moreover, paternal depressive symptoms alone do not lead to increased risk for emotional problems in these 2- and 5-year-old children. In contrast, even subclinical levels of maternal depressive symptoms in late pregnancy are associated with increased risk for their children's experiencing internalizing and externalizing emotional problems.

Development of sleep-wake rhythms during the first year of age.

Circadian rhythms refer to biological rhythms that have an endogenous period length of approximately 24 hr. However, not much is known about the variance in the development of the sleep-wake rhythm. The study objectives were (a) to describe the normative variation in the development of a sleep-wake rhythm in infancy, (b) to assess whether slower development is related to sleep quality and (c) to evaluate factors that are related to the slower development of a sleep-wake rhythm. The study is based on a representative birth cohort. Questionnaires at the ages of 3 (n = 1,427) and 8 months (n = 1,302) and actigraph measurement at 8 months (n = 372) were available. Infants with significant developmental delays (n = 11) were excluded. The results are based on statistical testing and multivariate modelling. We found that the average percentage of daytime sleep was 36.3% (standard deviation [SD], 8.5%) at 3 months and 25.6% (SD, 6.6%) at 8 months. At both time-points, infants with slower sleep-wake rhythm development slept more hours per day, had a later sleep-wake rhythm, more difficulties in settling to sleep and longer sleep-onset latency; they also spent a longer time awake during the night. According to actigraph registrations, we found that the infants with slow development of a sleep-wake rhythm slept less and had a later start and end to night-time sleep than the other infants. Infants' sleep-wake rhythm development is highly variable and is related to parent-reported and objectively measured sleep quality and quantity. Interventions to improve the sleep-wake rhythm might improve sleep quality in these infants.

Trajectories of mothers' and fathers' depressive symptoms from pregnancy to 24 months postpartum.

OBJECTIVES: This study investigated trajectories of mothers' and fathers' depressive symptoms from prenatal to 24 months postpartum. Prenatal correlates of the trajectories were also examined. METHODS: Mothers (N = 1670) and fathers (N = 1604) from the Finnish CHILD-SLEEP birth cohort, reported depressive symptoms at 32nd pregnancy week and 3, 8, and 24 months postpartum using the Center for Epidemiologic Studies Depression Scale (CES-D, 10-item). Profile analysis was used to group participants according to their longitudinal patterns of depressive symptoms. Prenatal predictors (sociodemographic, health, substance use, sleep, and stress related factors, family atmosphere) of depressive symptom trajectories as well as association between parents' trajectories were analyzed using multinomial logistic regression. RESULTS: For both mothers and fathers, a solution with three stable depressive symptom trajectories (low: 63.1% mothers and 74.9% fathers; moderate: 28.1% and 22.6%; high: 8.8% and 2.6%) was considered the best fitting and most informative. Insomnia, earlier depression, anxiousness, stressfulness, and poor family atmosphere predicted the moderate and high (compared to low) depressive symptom trajectories among both mothers and fathers in multivariate analyses. Mother's higher depressive symptom trajectory was significantly associated with father's higher symptom trajectory (p < 0.001). LIMITATIONS: Number of cases in the high depressive symptom trajectory group among fathers was low. CONCLUSIONS: Maternal and paternal depressive symptom trajectories from prenatal period up to two years postpartum seem stable, indicating the chronic nature of perinatal depressive symptoms. Mothers' and fathers' trajectories are associated with each other and their strongest predictors are common to both.

Variation near MTNR1A associates with early development and interacts with seasons.

Melatonin is a circadian regulatory hormone with neuroprotective properties. We have previously demonstrated the association of the genetic variant rs12506228 near the melatonin receptor 1A gene (MTNR1A) with intolerance to shift-work. Furthermore, this variant has been connected to Alzheimer's disease. Because of the previously suggested role of melatonin signalling in foetal neurocognitive and sleep development, we studied here the association of rs12506228 with early development. The study sample comprised 8-month-old infants from the Finnish CHILD-SLEEP birth cohort (n = 1,301). Parental questionnaires assessed socioemotional, communication and motor development, as well as sleep length and night awakenings. The A allele of rs12506228 showed an association with slower socioemotional (p = .025) and communication (p = .0098) development, but no direct association with sleep. However, the association of the Finnish seasons with infant sleep length interacted with rs12506228. Taken together, rs12506228 near MTNR1A, which has been previously linked to adult and elderly traits, is shown here to associate with slower early cognitive development. In addition, these results suggest that the darker seasons associate with longer infant sleep time, but only in the absence of the rs12506228 AA genotype. Because the risk allele has been connected to fewer brain MT1 melatonin receptors, these associations may reflect the influence of decreased melatonin signalling in early development.

Night Awakening and Its Association With Executive Functioning Across the First Two Years of Life.

Longitudinal associations between signaled night awakening and executive functioning (EF) at 8 and 24 months in children with (≥ 3 awakenings, n = 77) and without parent-rated fragmented sleep (≤ 1 awakening, n = 69) were studied. EF was assessed with the Switch task at 8 and 24 months. At 24 months, behavioral tasks and parental ratings of EF (Behavior Rating Inventory of Executive Function-Preschool version) were also used. In the Switch task, children with fragmented sleep were less able to learn stimulus sequences and inhibit previously learned responses than children without fragmented sleep. The groups differed only marginally in parental ratings of EF, and no differences were found in behavioral EF tasks. These results suggest that eye movement-based measures may reveal associations between sleep and EF already in infancy and toddlerhood.

The effect of being watched on facial EMG and autonomic activity in response to another individual's facial expressions.

We tested if facial reactions to another person's facial expressions depend on the self-relevance of the observed expressions. In the present study (n = 44), we measured facial electromyographic (zygomatic and corrugator) activity and autonomic arousal (skin conductance) responses to a live model's smiling and neutral faces. In one condition, the participant and the model were able to see each other normally, whereas in the other condition, the participant was led to believe that the model could not see the participant. The results showed that the increment of zygomatic activity in response to smiling faces versus neutral faces was greater when the participants believed they were being watched than it was when the participants believed they were not being watched. However, zygomatic responses to smiles did not differ between the conditions, while the results suggested that the participants' zygomatic responses to neutral faces seemed to attenuate in the condition of believing they were being watched. Autonomic responses to smiling faces were greater in the belief of being watched than in the belief of not being watched condition. The results suggest that the self-relevance of another individual's facial expression modulates autonomic arousal responses and to a lesser extent facial EMG responses.

Sleep Difficulties in Infancy Are Associated with Symptoms of Inattention and Hyperactivity at the Age of 5 Years: A Longitudinal Study.

OBJECTIVE: Sleep difficulties are associated with cognitive and behavioral problems in childhood. However, it is still unclear whether early sleep difficulties are related to later development. We studied whether parent-reported sleep duration, night awakenings, and parent-reported sleep problems in early childhood are associated with symptoms of inattention and hyperactivity at the age of 5 years. METHOD: Our study is based on the Child-Sleep birth cohort initially comprising 1673 families, of which 713 were retained at the age of 5 years. We used the Brief Infant Sleep Questionnaire and the Infant Sleep Questionnaire, which were filled out by the parents when their child was 3, 8, and 24 months and 5 years old. Symptoms of inattention and hyperactivity at the age of 5 years were assessed using the Strengths and Difficulties Questionnaire and the Five-to-Fifteen questionnaire. RESULTS: Sleep duration at the age of 3, 8, and 24 months was associated with inattentiveness at 5 years of age. Moreover, parent-reported sleep problems at the age of 24 months were related to both inattentive and hyperactive symptoms at the age of 5 years. Finally, at the age of 5 years, parent-reported sleep problems and night awakenings were associated with concurrent symptoms of inattention and hyperactivity. CONCLUSION: Our findings suggest that certain sleep characteristics related to sleep quality and quantity in early childhood are associated with inattentiveness and hyperactivity at the age of 5 years. Interestingly, sleep duration in early childhood is consistently related to inattention at the age of 5 years.