Reduced multiscale complexity of daily behavioral dynamics in autism spectrum disorder.

Aim: Autism spectrum disorder (ASD) is difficult to diagnose objectively due to its heterogeneous and complex manifestations. This study aimed to objectively characterize the behavioral phenotypes of ASD children by exploring the multiscale behavioral dynamics. Methods: We applied behavioral organization (BO) and multiscale sample entropy (MSE) analyses to physical activity data collected from ASD and typically developing children, using wearable monitors in their daily life. We also examined their correlation with auditory startle response measures and clinical questionnaires, including the Social Responsiveness Scale (SRS) and the Strengths and Difficulties Questionnaire (SDQ). Results: A significant decrease in MSE at timescales longer than 6 min was observed in ASD children, suggesting decreased irregularity or unpredictability, potentially linked to repetitive behaviors or stereotyped patterns commonly observed in ASD. Additionally, an increase in MSE positively correlated with prepulse inhibition levels, indicating its relationship with sensorimotor gating. Moreover, the observed significant negative correlation with the total difficulty score of SDQ substantiates MSE's potential as an objective metric for assessing general mental health problems associated with ASD. Conclusion: Multiscale analysis enhances the understanding of ASD's behavioral dynamics, providing valuable metrics for real-world assessments.

Associations between media exposure and mental health among children and parents after the Great East Japan Earthquake.

Background: Exposure to natural disaster media coverage is associated with mental health problems, but its long-term impacts are still unclear. Also, no study has analysed the psychological impact of exposure to natural disaster media coverage among children who are generally sensitive to threatening events.Objective: We aimed to examine how television images of victims after the 2011 Great East Japan Earthquake were associated with mental health among children and their parents.Methods: In 2012, questionnaires for sociodemographic factors were distributed to 2053 families. Parents who provided written consent were contacted in 2013 and invited to provide information on mental health problems (outcome) and retrospectively provide information on television watching at the time of the earthquake (exposure). We used data from 159 parents who completed the survey as the final sample. We used a dichotomous variable to evaluate exposure to media coverage. Multivariable regression was used to examine the association between exposure to television images of victims and mental health, adjusting for potential confounders. Bias-corrected and accelerated bootstrap confidence intervals (CIs) were used.Results: Exposure to television images of victims was significantly associated with worse psychopathology among children (ß, 1.51; 95% CI, 0.07-2.96) and greater psychological distress among their parents (ß, 1.49; 95% CI, 0.28-2.70). Child psychopathology and parental psychological distress were significantly correlated (r = 0.36, p < .001).Conclusions: Exposure to television images of disaster victims may produce long-term impacts on mental health among children and their parents. To reduce the likelihood of mental health problems associated with disasters, clinicians may recommend reducing exposure to television images of victims.

Television images of victims after the 2011 Great East Japan Earthquake were associated with worse psychopathology among children in 2013, adjusted for potential confounders.Similar associations were found in psychological distress among their parents.Child psychopathology and parental psychological distress were correlated with each other.

Association between autistic traits and binge drinking: Findings from Japan.

PURPOSE: Substance misuse may be elevated in some individuals with autism spectrum disorder (ASD). As yet, however, little is known about the association between autistic traits (AT) and substance use/misuse in adults. This study examined the association between AT and binge drinking (BD) among individuals in Japan. METHODS: Data were analyzed from 1452 individuals aged 18 and above collected during an online survey in February 2021. Self-reported information was obtained on BD assessed as consuming 5 or more (males) or 4 or more (females) drinks containing any kind of alcohol within a 2-h period. AT were assessed with the Japanese version of the Autism Spectrum Quotient - the AQ-J-10. Logistic regression analysis was used to examine associations. RESULTS: The prevalence of past-month BD was significantly higher in individuals with AT compared to those without AT (42.7% > 27.6%). In a fully adjusted analysis that controlled for mental health (anxiety, depression) and attention-deficit/hyperactivity disorder symptoms, individuals with AT had significantly higher odds for BD once a week or more often (OR: 1.54, 95%CI: 1.04-2.29). AT were also associated with significantly higher odds for BD among women (OR: 2.27, 95%CI: 1.08-4.76), and those aged 18-34 (OR: 2.37, 95%CI: 1.09-5.18) and aged 60 and above (OR: 2.15, 95%CI: 1.02-4.53). CONCLUSION: Individuals with AT have higher odds for BD. Increased efforts to detect alcohol use/misuse in adults with AT and AT in adults misusing alcohol may be efficacious in efforts to manage symptoms and eliminate harmful alcohol misuse.

Preliminary efficacy of cognitive-behavioral therapy on emotion regulation in adults with autism spectrum disorder: A pilot randomized waitlist-controlled study.

Previous studies have demonstrated the clinical utility of cognitive-behavioral therapy in improving emotion regulation in children on the autism spectrum. However, no studies have elucidated the clinical utility of cognitive-behavioral therapy in improving emotion regulation in autistic adults. The aim of the present pilot study was to explore the preliminary clinical utility of a group-based cognitive-behavioral therapy program designed to address emotion regulation skills in autistic adults. We conducted a clinical trial based on a previously reported protocol; 31 participants were randomly allocated to the intervention group and 29 to the waitlist control group. The intervention group underwent an 8-week program of cognitive-behavioral therapy sessions. Two participants from the intervention group withdrew from the study, leaving 29 participants (93.5%) in the group. Compared with the waitlist group, the cognitive-behavioral therapy group exhibited significantly greater pre-to-post (Week 0-8) intervention score improvements on the attitude scale of the autism spectrum disorder knowledge and attitude quiz (t = 2.21, p = 0.03, d = 0.59) and the difficulty describing feelings scale of the 20-item Toronto Alexithymia Scale (t = -2.07, p = 0.04, d = -0.57) in addition to pre-to-follow-up (Week 0-16) score improvements on the emotion-oriented scale of the Coping Inventory for Stressful Situations (t = -2.14, p = 0.04, d = -0.59). Our study thus provides preliminary evidence of the efficacy of the group-based cognitive-behavioral therapy program on emotion regulation in autistic adults, thereby supporting further evaluation of the effectiveness of the cognitive-behavioral therapy program in the context of a larger randomized clinical trial. However, the modest and inconsistent effects underscore the importance of continued efforts to improve the cognitive-behavioral therapy program beyond current standards.

Emotional and behavioral problems in Japanese preschool children with subthreshold autistic traits: findings from a community-based sample.

BACKGROUND: Recently, there has been a growing recognition that autistic traits exist along a continuum beyond diagnostic categories and that even subclinical symptoms may be associated with an increased risk for the psychosocial well-being and mental health of children. However, as yet, there has been little research on whether preschool children with autism spectrum disorder (ASD) symptoms, who do not meet the diagnostic criteria for ASD, are more likely to experience difficulties. To address this deficit this study examined whether young children with subthreshold autistic traits have an increased risk for emotional/behavioral difficulties. METHODS: Data were analyzed from 1057 Japanese preschool children aged 5-years old collected during the first wave of the Tama Children's Survey (TCS) cohort study. Parent-reported autistic traits were assessed with the Social Responsiveness Scale (SRS), while they provided information on their child's emotional/behavioral problems using the Strengths and Difficulties Questionnaire (SDQ). Logistic regression analysis was used to examine associations. RESULTS: Preschool children with mild-to-moderate autistic traits, corresponding to subclinical autism were significantly more likely to score above the clinical thresholds for emotional/behavioral problems compared to children with fewer autistic traits. Follow-up diagnostic assessments and analyses of 72 children from the cohort confirmed these findings and showed that these children with subthreshold autistic traits also had a significantly lower intelligence quotient (IQ) as measured by the Wechsler Preschool and Primary Scale of Intelligence (WPPSI). CONCLUSIONS: Although subthreshold autistic traits are difficult to define due to the sometimes vague border between typical and atypical development, there may be a large number of preschool children with subthreshold autistic traits, who may have an increased risk for a variety of different emotional/behavioral difficulties as well as lower cognitive functioning.

Training types associated with knowledge and experience in public health workers.

BACKGROUND: Training non-specialist workers in mental healthcare improves knowledge, attitude, confidence, and recognition of mental illnesses. However, still little information is available on which type of mental health training is important in the improvement of these capacities. METHODS: We studied web-based survey data of 495 public health workers to examine training types associated with knowledge and experience in supporting individuals with mental illness. Multivariable logistic regression analysis was conducted to evaluate the association between a lack of knowledge and experience (outcome) and mental health training (exposure). We fitted three regression models. Model 1 evaluated unadjusted associations. Model 2 adjusted for age and sex. Model 3 adjusted for age, sex, years of experience, mental health full-time worker status, and community population. Bias-corrected and accelerated bootstrap confidence intervals (CIs) were used. RESULTS: For all training types, the association between a lack of knowledge and experience and mental health training attenuated as the model developed. In Model 3, a lack of knowledge and experience was significantly associated with training in specific illness (OR, 0.54; 95% CI, 0.32-0.93) and screening and assessment (OR, 0.63; 95% CI, 0.39-0.99). Non-significant results were produced for training in counseling, psychosocial support, collaborative work, and law and regulation in Model 3. CONCLUSIONS: We believe that the present study provides meaningful information that training in specific illness and screening and assessment may lead to knowledge and experience of public health workers. Further studies should employ a longitudinal design and validated measurements.

Emotional and behavioral problems in Japanese preschool children with motor coordination difficulties: the role of autistic traits.

There has been little research on whether younger children with developmental coordination disorder (DCD) symptoms have an increased risk for emotional and behavioral problems. This study examined whether coordination difficulties are associated with emotional and behavioral problems (emotional symptoms, conduct problems, hyperactivity/inattention, peer problems, reduced prosocial behavior) in preschool children and the role of autistic traits in this association. Data (N = 1042, age 58-71 months) were analyzed from the Tama Children's Survey (TCS). The Little Developmental Coordination Disorder Questionnaire (LDCDQ) was used to measure coordination difficulty symptoms. Information was obtained on emotional/behavioral problems using the Strengths and Difficulties Questionnaire (SDQ) and on autistic traits with the Social Responsiveness Scale (SRS). Higher autistic traits were based on SRS cutoff scores (53.5 for boys and 52.5 for girls). Logistic regression analysis was used to assess associations between the variables. In adjusted models, children with probable DCD (pDCD) were significantly more likely to score above the clinical thresholds on all SDQ emotional/behavioral domains. However, nearly all of these associations became nonsignificant after including autistic traits in the analysis. Additional analyses showed that children with pDCD with higher autistic traits had significantly increased odds for emotional problems (odds ratio [OR]: 4.47, 95% confidence interval [CI]: 1.52-13.19), hyperactivity/inattention (OR: 3.74, 95% CI: 1.45-9.64), peer problems (OR: 15.81, 95% CI: 5.96-41.99), and total difficulties (OR: 28.78, 95% CI: 7.23-114.57), compared to children with pDCD alone. These results indicate that the increased risk of emotional/behavioral difficulties in preschool children with pDCD might be mediated by autistic traits.

Changes in self-efficacy in Japanese school-age children with and without high autistic traits after the Universal Unified Prevention Program: a single-group pilot study.

BACKGROUND: Research has shown the efficacy of school-based programs for mental health problems in children. However, few studies have focused on the strengths of children, such as resilience, which is essential in preventing mental health problems. Moreover, no research has investigated the effect of a universal school-based program on children with increased autistic traits in mainstream classes. We examined the changes in children's self-efficacy, social skills, and general mental health after the implementation of a newly developed universal program, the Universal Unified Prevention Program for Diverse Disorders (Up2-D2), and whether similar changes occurred in children with and without higher autistic traits. METHODS: To assess possible changes associated with the program, questionnaires were collected from 396 children (207 boys and 189 girls) aged 9-12 years old before (T1), immediately after (T2), and three months after (T3) the implementation of the program. RESULTS: Results from a linear mixed-effects model showed a significant increase in children's self-efficacy at T2 (adjusted difference 0.49, 95% CI 0.03-0.94; p < 0.05) and T3 (0.78, 95% CI 0.32-1.23; p < 0.001). There were also significant positive changes in social skills and general mental health. Similar changes were observed in children with high autistic traits. Autistic traits at T1 did not contribute to the degree of change in self-efficacy. CONCLUSIONS: Our pilot study suggests that a universal program has the potential to promote positive attitudes and mental health in both at-risk and not-at-risk children.

Association between sleep habits/disorders and emotional/behavioral problems among Japanese children.

Actual sleep status and the association between sleep habits/disorders and emotional/behavioral problems among children in the development stage have not been fully clarified. A questionnaire survey was conducted on the sleep habits/disorders (Brief Child Sleep Questionnaire; BCSQ) and emotional/behavioral problems (Strengths and Difficulties Questionnaire; SDQ) of 87,548 children enrolled in ordinary classes in nine grade levels from the first grade of elementary school to the third grade of junior high school from December 2009 to April 2010. As school grade increased, children's bedtimes were delayed and sleep duration was reduced by 2.0 h over the nine grade levels. Based on the BCSQ, 18.3% of children were judged to have some type of sleep disorder, and about 30% to 40% of children had sleep symptoms at bedtime, during sleep, and at wake time. Multiple regression analysis showed that emotional and behavioral problems were associated with presence of any sleep symptom, longer sleep latency, and longer awake time after sleep onset, whereas total sleep time was not. Sleep symptoms at wake time were most strongly associated with emotional and behavioral problems. Status of sleep habits/disorders should be considered when interpreting emotional/behavioral problems in school-age children.

Attention-deficit/hyperactivity disorder symptoms and sleep problems in preschool children: the role of autistic traits.

BACKGROUND: Sleep problems are elevated in children with attention-deficit/hyperactivity disorder (ADHD). However, until now there has been comparatively little research on the role of autistic traits in this association. The current study examined the association between ADHD symptoms and sleep problems in Japanese preschool children and whether autistic traits might also be important for this relationship. METHODS: Data were analyzed from 1053 children (average age 64.14 months, range 58-71; 50.3% male) that were drawn from the Tama Children's Survey (TCS). Parent-reported information was obtained on ADHD symptoms using the Strengths and Difficulties Questionnaire (SDQ) and autistic traits with the Social Responsiveness Scale Second Edition (SRS-2). Parents also provided information on three different categories of sleep problems experienced by their children - parasomnias, sleep disordered breathing and awakening/daytime problems. Ordinal logistic regression analysis was used to examine the associations. RESULTS: In analyses adjusted for sociodemographic factors, the mother's mental health and child's emotional problems, compared to children with no ADHD symptoms or autistic traits, children with only ADHD symptoms had significantly increased odds for only one of 11 individual sleep problems - waking in a negative mood. In contrast, children with comorbid ADHD symptoms and autistic traits had elevated odds for five sleep problems with odds ratios ranging from 2.10 (takes time to become alert in the morning) to 3.46 (excessive body movement while sleeping). CONCLUSIONS: Sleep problems may be especially elevated in children with comorbid ADHD symptoms and autistic traits.

Practical applications of brief screening questionnaires for autism spectrum disorder in a psychiatry outpatient setting.

OBJECTIVES: This study was designed to examine the diagnostic performance of the social and communication disorders checklist (SCDC) and strength and difficulties questionnaire (SDQ) to detect autism spectrum conditions (ASC), along with the social responsiveness scale-second edition (SRS-2) as reference, in a psychiatry outpatient setting. METHODS: We translated the SCDC into Japanese since its Japanese version was unavailable. We examined its test-retest reliability as well as the internal consistency reliability and diagnostic performance of the three questionnaires among 41 Japanese psychiatric outpatients, using the best-estimate diagnosis of ASC based on the diagnostic interview for social and communication disorders, as a gold standard. RESULTS: The test-retest reliability was high for the SCDC. Although the internal consistency reliability was high for the SCDC and SRS-2, that was low for the prosocial and peer problem subscales of the SDQ. The performance of the SCDC, SDQ, and SRS-2 to detect ASC was moderate: the area under the ROC curve of 0.78, 0.78, and 0.84, respectively. CONCLUSIONS: Although questionnaires to detect ASC, including the three examined, generally have only moderate performance in this setting, these can be successfully applied to high-risk populations such as psychiatry outpatients, when multi-level rather than dichotomous likelihood ratios are used.

Developing the universal unified prevention program for diverse disorders for school-aged children.

BACKGROUND: Psychological problems during childhood and adolescence are highly prevalent, frequently comorbid, and incur severe social burden. A school-based universal prevention approach is one avenue to address these issues. OBJECTIVE: The first aim of this study was the development of a novel, transdiagnostic cognitive-behavioral universal prevention program: The Universal Unified Prevention Program for Diverse Disorders (Up2-D2). The second aim of this study was to examine the acceptability and fidelity of the Up2-D2. METHODS: Classroom teachers who attended a 1-day workshop implemented the Up2-D2 independently as a part of their regular curricula. To assess the acceptability of the Up2-D2, 213 children (111 boys and 102 girls) aged 9-12 years completed questionnaires about their enjoyment, comprehension, attainment, applicability, and self-efficacy after completing Lessons 1-12. For fidelity, research assistants independently evaluated audio files that were randomly selected and assigned (27.3%). RESULTS: Our preliminary evaluation revealed the program was highly enjoyable, clear, and applicable for students. In addition, self-efficacy demonstrated a trend of gradually increasing over the 12 sessions. The total fidelity observed in the two schools was sufficient (76.2%), given the length of the teacher training. CONCLUSIONS: The results of this study supported the theory that the Up2-D2 could be feasible in real-world school settings when classroom teachers implement the program. We discussed current research and practical issues of using universal prevention to address mental health problems in school, based on implementation science for user-centered design.

Attention deficit/hyperactivity disorder and future expectations in Russian adolescents.

In recent years, there has been an increasing focus on the role of future expectations-the extent to which a future outcome is deemed likely-in the health and well-being of adolescents, with research linking future expectations to outcomes such as an increased likelihood of engaging in risky health behaviors. As yet, however, there has been no research on future expectations and attention deficit/hyperactivity disorder (ADHD) in adolescence. To address this research gap, the current study examined the association between ADHD symptoms/possible ADHD status and future expectations in a school-based sample of adolescents. Data were analyzed from 537 Russian adolescents (aged 12-17) with teacher-reported ADHD symptoms and self-reported future expectations. Logistic regression analysis was used to examine associations. In fully adjusted analyses, inattention symptoms/possible ADHD inattentive status was associated with lower future educational expectations, while a possible ADHD hyperactivity status was associated with increased odds for negative future expectations relating to work, family and succeeding in what is most important. The findings of this study suggest that greater ADHD symptoms/possible ADHD status in adolescence may be linked to an increased risk for negative future expectations across a variety of different life domains.

The orbitofrontal cortex modulates parenting stress in the maternal brain.

Many mothers are adaptive, deploying successful coping strategies that mitigate the deleterious effects of parenting stress on caregiving, nevertheless, the neural mechanisms underlying these adaptive responses remain unclear. We utilized functional magnetic resonance imaging to investigate brain activity in 28 healthy mothers of typically developing, 2-to-3-year-old children in response to the feeding behavior of their own children versus that of other children. We then examined the correlation between maternal brain activation and subjective feelings of parenting stress. Brain regions associated with maternal motivation including the orbitofrontal cortex (OFC), ventral pallidum, periaqueductal gray (PAG), dorsal raphe nucleus (DRN), and anterior insular cortex (AIC)-as well as those associated with the recognition of one's own child's state (e.g., cerebellum)-exhibited significant activation in response to their own children. While mothers with higher activation in the OFC showed less parenting stress related to one's sense of competence in the parental role, mothers with higher co-activation of the OFC with both of the AIC and PAG/DRN, and with the cerebellum showed less parenting stress caused by child characteristics. Our findings suggest that well-balanced maternal brain mechanisms integrated by the OFC may provide effective adaptive responses in daily parenting scenarios.

Relationship of the Acoustic Startle Response and Its Modulation to Adaptive and Maladaptive Behaviors in Typically Developing Children and Those With Autism Spectrum Disorders: A Pilot Study.

Background: Autism spectrum disorder (ASD) is associated with persistent impairments in adaptive functioning across multiple domains of daily life. Thus, investigation of the biological background of both adaptive and maladaptive behaviors may shed light on developing effective interventions for improving social adaptation in ASD. In this study, we examined the relationship between adaptive/maladaptive behaviors and the acoustic startle response (ASR) and its modulation, which are promising neurophysiological markers for ASD translational research. Method: We investigated the ASR and its modulation in 11 children with ASD and 18 with typical development (TD), analyzing the relationship between startle measures and adaptive/maladaptive behaviors assessed with the Vineland Adaptive Behavior Scales (VABS) Second Edition. Results: Peak-ASR latency was negatively correlated with the VABS total score and socialization domain score of adaptive behaviors, while the ASR magnitude for relatively weak stimuli of 75-85 dB was positively correlated with VABS maladaptive behavior scores. Prepulse inhibition (PPI) at the prepulse intensity of 70-75 dB was also correlated with VABS maladaptive behavior. However, these relationships did not remain significant after adjustment for multiple comparisons. Conclusions: Our results indicate that the prolonged peak-ASR latency of ASD children might be associated with impairment in the developmental level of adaptive behavior, and that the greater ASR magnitude to relatively weak acoustic stimuli and smaller PPI of ASD children might increase the risk of maladaptive behavior. Future studies that have larger sample sizes will be important for further elucidating the neurophysiological factors that underpin adaptive as well as maladaptive behaviors in ASD.

Stability of Autistic Traits from 5 to 8 Years of Age Among Children in the General Population.

Little is known about the across time stability of autistic traits during the transition period from preschool to school age in the general population. The current study compared autistic traits assessed by a mother-reported quantitative measure, the Social Responsiveness Scale, at age 5 and 8 years and examined the intraclass correlation coefficients of scores across the period for 168 Japanese community-based children. Results showed that total and two subdomain-related autistic trait scores remained primarily stable in males and females. This stability was observed for both children with higher and lower autistic traits scores with a possible sex-specific pattern. Our findings suggest that autistic traits in the general population can be reliably assessed using quantitative measures for this age period.

Prevalence of childhood obstructive sleep apnea syndrome and its role in daytime sleepiness.

OBJECTIVES: To investigate childhood obstructive sleep apnea syndrome (OSAS) and its role in daytime sleepiness among school-age children. METHODS: A questionnaire survey was conducted with 25,211 children aged 6-15 (mean, 10.39) years attending 148 elementary and 71 middle schools in 10 prefectures across Japan and their parents. Questions concerned 4 sleep habit items (bedtime, sleep onset latency, wake time after sleep onset, wake-up time) and 4 sleep disorder items (loud snoring, snorts/gasps, breathing pauses, seems very sleepy in the daytime). Total sleep time (TST) was calculated with sleep habits. Severe possible OSAS (p-OSAS) was defined as having loud snoring, snorts and gasps, or breathing pauses "frequently" (≥ 5 times per week), and mild p-OSAS was rated as having any of these "sometimes" (2-4 times per week). Severe daytime sleepiness was defined as seeming very sleepy "frequently" and mild daytime sleepiness as seeming very sleepy "sometimes". RESULTS: Mean prevalence of mild to severe p-OSAS and severe p-OSAS in children across all grade levels was 9.5% and 1.6%, respectively. p-OSAS was particularly prevalent in children at lower elementary levels, decreasing with advancing grade levels. Prevalence of mild and severe daytime sleepiness was 6.1% and 0.9%, respectively, among all children (7.0%). Prevalence of daytime sleepiness increased with advancing grade levels, particularly in middle-school level. Average TST was 8.4 ± 2.2 h in both elementary and middle-school levels, and decreased as grades advanced, particularly in middle-school levels. Multivariate logistic regression analysis showed that middle-school level, TST < 8 h, and p-OSAS were independent factors for daytime sleepiness. Strong correlations were found between severe daytime sleepiness and severe p-OSAS or TST < 6 h, and between daytime sleepiness and loud snoring or breathing pauses. CONCLUSION: p-OSAS may be an independent factor influencing daytime sleepiness in school-age children. Loud snoring and breathing pauses could be clinical markers for children with severe daytime sleepiness.

Relationship between Autistic Spectrum Trait and Regional Cerebral Blood Flow in Healthy Male Subjects.

OBJECTIVE: Autistic spectrum traits are postulated to lie on a continuum that extends between individuals with autism and individuals with typical development. The present study was carried out to investigate functional and network abnormalities associated with autistic spectrum trait in healthy male subjects. METHODS: Subjects were 41 healthy male subjects who underwent the social responsiveness scale-adult (SRS-A) and magnetic resonance imaging. RESULTS: There was significant positive correlation between the total score of SRS-A and the regional cerebral blood flow (CBF) in posterior cingulate cortex (PCC). Also, there were changes in functional network such as in cingulate corti, insula and fusiform cortex. Further, we also found the significant difference of functional networks between the healthy male subjects with high or low autistic spectrum trait, and these points were congruent with the previous perceptions derived from autistic-spectrum disorders. CONCLUSION: These findings suggest a biological basis for the autistic spectrum trait and may be useful for the imaging marker of autism symptomatology.

Acoustic Hyper-Reactivity and Negatively Skewed Locomotor Activity in Children With Autism Spectrum Disorders: An Exploratory Study.

Investigation of objective and quantitative behavioral phenotypes along with neurobiological endophenotypes might lead to increased knowledge of the mechanisms that underlie autism spectrum disorders (ASD). Here, we investigated the association between locomotor dynamics and characteristics of the acoustic startle response (ASR) and its modulation in ASD (n = 14) and typically developing (TD, n = 13) children. The ASR was recorded in response to acoustic stimuli in increments of 10 dB (65-105 dB SPL). We calculated the average ASR magnitude for each stimulus intensity and peak-ASR latency. Locomotor activity was continuously measured with a watch-type actigraph. We examined statistics of locomotor activity, such as mean activity levels and the skewness of activity. Children with ASD had a significantly greater ASR magnitude in response to a weak acoustic stimulus, which reflects acoustic hyper-reactivity. The skewness of all-day activity was significantly more negative in children with ASD than those with TD. Skewness of daytime activity was also more negative, although only of borderline statistical significance. For all children, the higher mean and more negatively skewed daytime activity, reflecting hyperactivity that was associated with sporadic large daytime "troughs," was significantly correlated with acoustic hyper-reactivity. The more negatively skewed locomotor activity occurring in the daytime was also associated with impaired sensorimotor gating, examined as prepulse inhibition at a prepulse intensity of 70 dB. This comprehensive investigation of locomotor dynamics and the ASR extends our understanding of the neurophysiology that underlies ASD.