Conducting unattended home sleep studies in children with narcolepsy and healthy matched controls: a feasibility study

Introduction: We investigated the technical feasibility and acceptability of conducting unattended home sleep studies for research purposes in children with and without narcolepsy. Methods: 23 children with narcolepsy (age: 8-15 years) and 23 healthy gender and age-matched controls were recruited. As part of a larger descriptive study called ‘The Paediatric Narcolepsy Project’, we aimed to investigate the differences in sleep architecture between children with and without narcolepsy. Children underwent home polysomnography (PSG) using a portable PSG system (Embla® Systems). A standard montage was used to measure sleep architecture with nine EEG channels (F3, F4, C3, Cz, C4, O1, O2, M1, M2), two electro-oculography (EOG) and two electromyography (EMG) channels. All children were set up in their own homes by the researcher. Study failure was defined as sleep recordings with less than four hours of interpretable sleep data. Four hours of sleep was deemed acceptable to capture two sleep cycles. Failed home studies were classified into three main areas of sensor removal, equipment failure or battery failure. Results: 22/23 children with narcolepsy (male=15, female=8) underwent home PSG. One child declined due to a previous negative PSG experience in hospital. Similarly, 22/23 matched controls underwent the sleep recording. One child became unwell during the set up, so did not proceed.16/22 (73%) of the children with narcolepsy were successfully studied and all of the control children were successfully studied. Discussion: This research has shown that conducting unattended home sleep studies to measure sleep architecture in children with narcolepsy and healthy controls for research purposes is feasible and is tolerated by the majority of children. However, our data show that unattended home sleep studies carry a risk of data loss, even when set up in the home by a trained researcher

Language Structure Is Partly Determined by Social Structure

BACKGROUND: Languages differ greatly both in their syntactic and morphological systems and in the social environments in which they exist. We challenge the view that language grammars are unrelated to social environments in which they are learned and used. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a statistical analysis of >2,000 languages using a combination of demographic sources and the World Atlas of Language Structures--a database of structural language properties. We found strong relationships between linguistic factors related to morphological complexity, and demographic/socio-historical factors such as the number of language users, geographic spread, and degree of language contact. The analyses suggest that languages spoken by large groups have simpler inflectional morphology than languages spoken by smaller groups as measured on a variety of factors such as case systems and complexity of conjugations. Additionally, languages spoken by large groups are much more likely to use lexical strategies in place of inflectional morphology to encode evidentiality, negation, aspect, and possession. Our findings indicate that just as biological organisms are shaped by ecological niches, language structures appear to adapt to the environment (niche) in which they are being learned and used. As adults learn a language, features that are difficult for them to acquire, are less likely to be passed on to subsequent learners. Languages used for communication in large groups that include adult learners appear to have been subjected to such selection. Conversely, the morphological complexity common to languages used in small groups increases redundancy which may facilitate language learning by infants. CONCLUSIONS/SIGNIFICANCE: We hypothesize that language structures are subjected to different evolutionary pressures in different social environments. Just as biological organisms are shaped by ecological niches, language structures appear to adapt to the environment (niche) in which they are being learned and used. The proposed Linguistic Niche Hypothesis has implications for answering the broad question of why languages differ in the way they do and makes empirical predictions regarding language acquisition capacities of children versus adults

Paediatric Narcolepsy: A Review of Diagnosis and Management

Narcolepsy is a chronic disabling neurological sleep disorder that requires lifelong treatment. We have outlined the clinical features of narcolepsy, the assessment and diagnosis process and have summarised the existing treatment options for children and adolescents with narcolepsy. In the future, the approach to management of paediatric narcolepsy should ideally be in a multidisciplinary setting, involving specialists in sleep medicine, sleep physiology, neurologists and psychologists/psychiatrists. A multidisciplinary approach will help to manage the potential impact of narcolepsy on children and adolescents who are in a stage of their life that is critical to their physical, emotional and social development and their academic attainment

Effects of speaker emotional facial expression and listener age on incremental sentence processing

Carminati MN, Knoeferle P. Effects of speaker emotional facial expression and listener age on incremental sentence processing. PLoS ONE. 2013;8(9): e72559.We report two visual-world eye-tracking experiments that investigated how and with which time course emotional information from a speaker's face affects younger (N = 32, Mean age = 23) and older (N = 32, Mean age = 64) listeners’ visual attention and language comprehension as they processed emotional sentences in a visual context. The age manipulation tested predictions by socio-emotional selectivity theory of a positivity effect in older adults. After viewing the emotional face of a speaker (happy or sad) on a computer display, participants were presented simultaneously with two pictures depicting opposite-valence events (positive and negative; IAPS database) while they listened to a sentence referring to one of the events. Participants' eye fixations on the pictures while processing the sentence were increased when the speaker's face was (vs. wasn't) emotionally congruent with the sentence. The enhancement occurred from the early stages of referential disambiguation and was modulated by age. For the older adults it was more pronounced with positive faces, and for the younger ones with negative faces. These findings demonstrate for the first time that emotional facial expressions, similarly to previously-studied speaker cues such as eye gaze and gestures, are rapidly integrated into sentence processing. They also provide new evidence for positivity effects in older adults during situated sentence processing