Delayed visual orienting responses in children with developmental and/or intellectual disabilities

Relationship between maternal biological features, environmental factors, and newborn neuromotor development associated with visual fixation abilities

Newborn visual fixation abilities predict future cognitive, perceptive, and motor skills. However, little is known about the factors associated with the newborn visual fixation, which is an indicator of neurocognitive abilities. We analyzed maternal biological and environmental characteristics associated with fine motor skills (visual tracking) in 1 month old infants. Fifty-one infants were tested on visual tracking tasks (Infant Visuomotor Behavior Assessment Scale/ Guide for the Assessment of Visual Ability in Infants) and classified according to visual conducts scores. Differences between groups were compared considering motor development (Alberta Infant Motor Scale) maternal mental health (Edinburgh Postnatal Depression Scale and Hamilton Anxiety Scale); home environment (Affordances in the Home Environment for Development Scale); maternal care (Coding Interactive Behavior); breastmilk composition (total fatty acids, proteins, and cortisol); and maternal metabolic profile (serum hormones and interleukins). Mothers of infants with lower visual fixation scores had higher levels of protein in breastmilk at 3 months. Mothers of infants with better visual conduct scores had higher serum levels of T4 (at 1 month) and prolactin (at 3 months). There were no associations between visual ability and motor development, home environment, or maternal care. Early newborn neuromotor development, especially visual and fine motor skills, is associated with maternal biological characteristics (metabolic factors and breastmilk composition), highlighting the importance of early detection of maternal metabolic changes for the healthy neurodevelopment of newborns.

Oculomotor response to images in primary school children with mild intellectual disability

Oculomotor activity (eye movements) is an essential component of visual data acquisition, analysis and use. The aim of this study was to determine the characteristics of oculomotor response to static images in primary school children with mild intellectual disability (ID). Our sample included a total of 49 schoolers (23 children with mild ID and 26 typically developing children). Oculomotor activity was evaluated using a GP3 Gazepoint eye tracker. The participants were presented with 15 visual stimuli: 10 pictorial and 5 mixed (pictures + text) static color images. Children with mild ID generated significantly fewer fixations (р = 0.038) than typically developing children. So, learning materials containing both pictorial and textual images are ineffective because textual elements are completely ignored by children with mild ID. The total duration of gaze fixations was significantly longer (р = 0.029) in typically developing children than in children with mild ID. However, the average duration of a single gaze fixation was longer in children with mild ID. The identified features of oculomotor response can help to optimize the format of instructional materials for primary school children with mild ID.

Objective assessment of sleep and sleep problems in older adults with intellectual disabilities

Little is known about sleep in older adults with intellectual disability (ID). Aim of this study was to investigate sleep and its associated factors, and to estimate the prevalence of sleep problems in this population. This study was part of the healthy aging and intellectual disabilities study. Sleep was assessed using the Actiwatch, a watch-like device that measures sleep and wakefulness based on movement activity. Participants (n=551) wore the Actiwatch at least seven days and nights continuously. Variables of interest were time in bed (TIB), sleep onset latency, total sleep time, wake after sleep onset, sleep efficiency and get-up time latency. Multivariate analyses were used to investigate factors associated with these sleep parameters. Provisional definitions were drafted to estimate the prevalence of sleep problems. Mean TIB was 630 min. Longer TIB was independently associated with higher age, more severe level of ID, living at a central facility, wheelchair dependence, female gender and depressive symptoms (adjusted R(2)=.358, F-change=8.302, p<.001). The prevalence of sleep problems was 23.9% settling problem, 63.1% night waking problem, 20.9% short sleep time, 9.3% early waking problem. 72% of the participants had at least one problem, 12.3% had three or more sleep problems. Older adults with ID lie in bed very long, and the prevalence of sleep problems is high. Further research should focus on causality of the relationships found in this study, and effects of sleep problems on health and well-being in this population.

Circadian sleep-wake rhythm of older adults with intellectual disabilities

The circadian sleep-wake rhythm changes with aging, resulting in a more fragmented sleep-wake pattern. In individuals with intellectual disabilities (ID), brain structures regulating the sleep-wake rhythm might be affected. The aims of this study were to compare the sleep-wake rhythm of older adults with ID to that of older adults in the general population, and to investigate which factors are associated with the sleep-wake rhythm in older adults with ID. This study is part of the 'Healthy Aging and Intellectual Disabilities' study (HA-ID). We applied actigraphy in 551 persons with ID and 58 persons in the general population, aged 50 years and over. Outcome measures were stability (interdaily stability), fragmentation (intradaily variability) and amplitude (relative amplitude) of the sleep-wake rhythm. Compared to older adults in the general population, the sleep-wake rhythm of older adults with ID was significantly less stable (p=0.03), more fragmented (p<0.001) and had a lower relative amplitude (p<0.001). Multivariate regression analysis revealed that higher age, dementia, depression, visual impairment, severe hearing impairment, epilepsy and spasticity are independently associated with a more disturbed sleep-wake rhythm in this group. The sleep-wake rhythm is more stable in females and those living at a setting for more intensive care. Higher physical activity levels are strongly associated with both a less fragmented (p<0.001) and a more stable (p<0.001) sleep-wake rhythm. Higher age, dementia and depression are also associated with the sleep-wake rhythm in the general population. Neurological and sensory impairments that were associated with the sleep-wake rhythm in older adults with ID, are frequent known conditions in the ID population. Further research should focus on which factors specifically influence the sleep-wake rhythm in older adults with ID, and on the effects of more physical daytime activity on the sleep-wake rhythm in this population.

Factors related to impaired visual orienting behavior in children with intellectual disabilities

It is generally assumed that children with intellectual disabilities (ID) have an increased risk of impaired visual information processing due to brain damage or brain development disorder. So far little evidence has been presented to support this assumption. Abnormal visual orienting behavior is a sensitive tool to evaluate impaired visual information processing. Therefore, the main objective of this study was to investigate possible correlations between the children's characteristics (age, gender, level of ID, mobility, gestational age, cerebral palsy, Down syndrome, visual acuity, strabismus, nystagmus, and epilepsy), and abnormal visual orienting behavior. We quantified data on visual orienting behavior, in terms of visual processing time and ocular motor fixations, in 88 children with ID aged 4-14 years. These visual parameters were combined with data collected from the children's medical records (predictors) and were put in a Pearson bivariate correlation analysis. A predictor was included for multiple regression analysis if the Pearson's correlation coefficient had a level of significance of p<0.05. As shown by multiple regression analysis, age, level of ID, and Down syndrome significantly affected visual processing time. Mobility, strabismus, and nystagmus significantly affected fixation quality. Using a systematic approach, we confirmed the hypothesis that children with ID have an increased risk of impaired visual information processing which is related to a low IQ.