Exploring an objective measure of overactivity in children with rare genetic syndromes.

BACKGROUND: Overactivity is prevalent in several rare genetic neurodevelopmental syndromes, including Smith-Magenis syndrome, Angelman syndrome, and tuberous sclerosis complex, although has been predominantly assessed using questionnaire techniques. Threats to the precision and validity of questionnaire data may undermine existing insights into this behaviour. Previous research indicates objective measures, namely actigraphy, can effectively differentiate non-overactive children from those with attention-deficit hyperactivity disorder. This study is the first to examine the sensitivity of actigraphy to overactivity across rare genetic syndromes associated with intellectual disability, through comparisons with typically-developing peers and questionnaire overactivity estimates. METHODS: A secondary analysis of actigraphy data and overactivity estimates from The Activity Questionnaire (TAQ) was conducted for children aged 4-15 years with Smith-Magenis syndrome (N=20), Angelman syndrome (N=26), tuberous sclerosis complex (N=16), and typically-developing children (N=61). Actigraphy data were summarized using the M10 non-parametric circadian rhythm variable, and 24-hour activity profiles were modelled via functional linear modelling. Associations between actigraphy data and TAQ overactivity estimates were explored. Differences in actigraphy-defined activity were also examined between syndrome and typically-developing groups, and between children with high and low TAQ overactivity scores within syndromes. RESULTS: M10 and TAQ overactivity scores were strongly positively correlated for children with Angelman syndrome and Smith-Magenis syndrome. M10 did not substantially differ between the syndrome and typically-developing groups. Higher early morning activity and lower evening activity was observed across all syndrome groups relative to typically-developing peers. High and low TAQ group comparisons revealed syndrome-specific profiles of overactivity, persisting throughout the day in Angelman syndrome, occurring during the early morning and early afternoon in Smith-Magenis syndrome, and manifesting briefly in the evening in tuberous sclerosis complex. DISCUSSION: These findings provide some support for the sensitivity of actigraphy to overactivity in children with rare genetic syndromes, and offer syndrome-specific temporal descriptions of overactivity. The findings advance existing descriptions of overactivity, provided by questionnaire techniques, in children with rare genetic syndromes and have implications for the measurement of overactivity. Future studies should examine the impact of syndrome-related characteristics on actigraphy-defined activity and overactivity estimates from actigraphy and questionnaire techniques.

Higher level domain specific skills in mathematics; The relationship between algebra, geometry, executive function skills and mathematics achievement.

Algebra and geometry are important components of mathematics that are often considered gatekeepers for future success. However, most studies that have researched the cognitive skills required for success in mathematics have only considered the domain of arithmetic. We extended models of mathematical skills to consider how executive function skills play both a direct role in secondary-school-level mathematical achievement as well as an indirect role via algebra and geometry, alongside arithmetic. We found that verbal and visuospatial working memory were indirectly associated with mathematical achievement via number fact knowledge, calculation skills, algebra and geometry. Inhibition was also indirectly associated with mathematical achievement via number fact knowledge and calculation skills. These findings highlight that there are multiple mechanisms by which executive function skills may be involved in mathematics outcomes. Therefore, using specific measures of mathematical processes as well as context-rich assessments of mathematical achievement is important to understand these mechanisms.

The developmental trajectory of sleep in children with Smith-Magenis syndrome compared to typically developing peers: a 3-year follow-up study.

Study Objectives: To determine the trajectory of: (i) objective sleep parameters and (ii) caregiver-reported sleep questionnaire scores over 3 years in children with Smith-Magenis syndrome (SMS) compared to age-matched typically developing (TD) controls. We also aimed to (iii) describe individual profiles of change in sleep parameters over time. Methods: Week-long, overnight actigraphy and questionnaire data from 13 children with SMS and 13 age-matched TD children were collected at Time 1 and Time 2 (3 years later). Independent samples t-tests, paired samples t-tests, and Bayesian analyses were used to compare sleep parameters and sleep questionnaire scores between groups at each time point and compare data within groups to assess change over time. Results: Sleep parameters were consistently more disrupted in the SMS group than the TD group, with significantly reduced sleep efficiency, increased wake after sleep onset and earlier get up times at both time points. This was mirrored in the questionnaire data, with children with SMS evidencing higher scores for overall sleep disturbance, night waking, and daytime sleepiness. While TD sleep parameters demonstrated expected developmental changes over 3 years, in the SMS group sleep parameters and variability between and within children remained largely stable. However, some children with SMS showed substantial variation in sleep parameters over time. Questionnaire scores remained stable over 3 years in both groups. Conclusions: Overall, sleep disturbance appears to be a stable feature of SMS, indicative of a divergent sleep trajectory compared to TD peers. Proactive intervention approaches should be considered for poor sleep in SMS.

Positive impact of sleep on recall of multiplication facts.

This study tested the hypothesis that learning complex multiplication problems (e.g. 8 × 23 = 184) prior to sleep would benefit recall in adult participants compared with learning the problems prior to a period of wakefulness. This study used a within-participant design where all participants learnt complex multiplication problems in two conditions separated by one week. In one condition, learning was before bed (sleep learning condition) and in the other condition learning was in the morning (wake learning condition). In each condition, recall was tested approximately 10.5 h later. Data were collected online from 77 participants. In the subset of the sample with greater than or equal to 60% accuracy at the initial learning session (n = 37), the sleep learning condition participants had better recall compared with the wake learning condition. This equated to a moderate effect size, Cohen's d = 0.51. Regardless of initial levels of learning (n = 70) the same beneficial effect of sleep on recall was found with a small effect size, Cohen's d = 0.33. This study has identified a beneficial effect of learning prior to sleep on recall of complex multiplication problems compared with learning these problems during the daytime. Future research should explore whether similar effects are observed with children learning simple multiplication facts.