Consolidation of vocabulary is associated with sleep in typically developing children, but not in children with dyslexia.

Sleep is known to play an active role in consolidating new vocabulary in adults; however, the mechanisms by which sleep promotes vocabulary consolidation in childhood are less well understood. Furthermore, there has been no investigation into whether previously reported differences in sleep architecture might account for variability in vocabulary consolidation in children with dyslexia. Twenty-three children with dyslexia and 29 age-matched typically developing peers were exposed to 16 novel spoken words. Typically developing children showed overnight improvements in novel word recall; the size of the improvement correlated positively with slow wave activity, similar to previous findings with adults. Children with dyslexia showed poorer recall of the novel words overall, but nevertheless showed overnight improvements similar to age-matched peers. However, comparisons with younger children matched on initial levels of novel word recall pointed to reduced consolidation in dyslexics after 1 week. Crucially, there were no significant correlations between overnight consolidation and sleep parameters in the dyslexic group. This suggests a reduced role of sleep in vocabulary consolidation in dyslexia, possibly as a consequence of lower levels of learning prior to sleep, and highlights how models of sleep-associated memory consolidation can be usefully informed by data from typical and atypical development.

Consolidation of vocabulary is associated with sleep in children.

Although the acquisition of a novel word is apparently rapid, adult research suggests that integration of novel and existing knowledge (measured by engagement in lexical competition) requires sleep-associated consolidation. We present the first investigation of whether a similar time-course dissociation characterizes word learning across development. Consistent with previous research but counter to adults, 7-12-year-olds showed sleep-associated consolidation effects in declarative but not procedural memory. Nevertheless, the relationship between sleep and word learning in children was remarkably similar to the pattern for adults. Following exposure to nonword competitors (e.g. biscal) in the a.m. or p.m., children's ability to recognize and recall the nonwords improved only after sleep (after approximately 12-hrs for the p.m. group and 24-hrs for the a.m. group), with performance stable 1 week later. Novel nonwords only induced lexical competition effects after sleep. These findings suggest that children utilize a dual memory system when acquiring and integrating new vocabulary and highlight sleep as integral to this process. A video abstract of this article can be viewed at http://www.youtube.com/watch?feature=youtube_gdata&v=2UNuKCAakOk&gl=GB.

The role of working memory and contextual constraints in children's processing of relative clauses.

An auditory sentence comprehension task investigated the extent to which the integration of contextual and structural cues was mediated by verbal memory span with 32 English-speaking six- to eight-year-old children. Spoken relative clause sentences were accompanied by visual context pictures which fully (depicting the actions described within the relative clause) or partially (depicting several referents) met the pragmatic assumptions of relativization. Comprehension of the main and relative clauses of centre-embedded and right-branching structures was compared for each context. Pragmatically appropriate contexts exerted a positive effect on relative clause comprehension, but children with higher memory spans demonstrated a further benefit for main clauses. Comprehension for centre-embedded main clauses was found to be very poor, independently of either context or memory span. The results suggest that children have access to adult-like linguistic processing mechanisms, and that sensitivity to extralinguistic cues is evident in young children and develops as cognitive capacity increases.

A systematic review of cognitive function and psychosocial well-being in school-age children with narcolepsy.

In August 2010, concerns were raised about an increase in the incidence rate of narcolepsy diagnosis in children and adolescents. Narcolepsy is a chronic neurological sleep disorder characterised by excessive daytime sleepiness and attacks of muscle weakness which are often precipitated by strong emotions, known as cataplexy. We systematically examined and updated the scientific literature on the consequences of narcolepsy on cognitive function and psychosocial well-being in school-age children. Eight studies published between 2005 and 2015 were eligible for inclusion in this review. Collectively the results provide evidence to suggest that children who develop narcolepsy are at significant risk of cognitive impairment in at least one domain and emotional problems including depression, anxiety and low self-esteem. Children with narcolepsy should be monitored carefully in order to manage and reduce the impact of any impairments present. The existing literature is limited by small sample sizes, lack of appropriate controls and lack of longitudinal data. Future research should aim to address the limitations of the current work and aim to determine the underlying cause of cognitive and psychological impairments. This will enable the design of effective interventions to support children with narcolepsy so that they are able to achieve their full potential.

Graphic imagery is not sufficient for increased attention to cigarette warnings: the role of text captions.

AIMS: The present study aims to assess the extent to which attention to UK cigarette warnings is attributable to the graphic nature of the content. DESIGN: A visual dot probe task was utilised, with the warnings serving as critical stimuli that were manipulated for the presence of graphic versus neutral image content, and the accompanying text caption. This mixed design yielded image content (graphic versus neutrally-matched images) and presence (versus absence) of text caption as within subjects variables and smoking status as a between-participants variable. SETTING: The experiment took place within the laboratories of a UK university. PARTICIPANTS: Eighty-six psychology undergraduates (51% smokers, 69% female), predominantly of Caucasian ethnicity took part. MEASUREMENTS: Reaction times towards probes replacing graphic images relative to probes replacing neutral images were utilised to create an index of attentional bias. FINDINGS: Bias scores (M = 10.20 ± 2.56) highlighted that the graphic image content of the warnings elicited attentional biases (relative to neutral images) for smokers. This only occurred in the presence of an accompanying text caption [t (43) = 3.950, P < 0.001] as opposed to when no caption was present [t (43) = 0.029, P = 0.977]. Non-smokers showed no biases in both instances. CONCLUSIONS: Graphic imagery on cigarette packets increases attentional capture, but only when accompanied by a text message about health risks.

The kindergarten path effect revisited: children's use of context in processing structural ambiguities.

Research with adults has shown that ambiguous spoken sentences are resolved efficiently, exploiting multiple cues--including referential context--to select the intended meaning. Paradoxically, children appear to be insensitive to referential cues when resolving ambiguous sentences, relying instead on statistical properties intrinsic to the language such as verb biases. The possibility that children's insensitivity to referential context may be an artifact of the experimental design used in previous work was explored with 60 4- to 11-year-olds. An act-out task was designed to discourage children from making incorrect pragmatic inferences and to prevent premature and ballistic responses by enforcing delayed actions. Performance on this task was compared directly with the standard act-out task used in previous studies. The results suggest that young children (5 years) do not use contextual information, even under conditions designed to maximize their use of such cues, but that adult-like processing is evident by approximately 8 years of age. These results support and extend previous findings by Trueswell and colleagues (Cognition (1999), Vol. 73, pp. 89-134) and are consistent with a constraint-based learning account of children's linguistic development.