Cinzia Arzilli

The effect of a daytime nap on priming and recognition tasks in preschool children.

STUDY OBJECTIVES The beneficial effect of sleep on memory consolidation is widely accepted in the adult population and has recently been shown in children. However, the few available data almost exclusively refer to school-aged children. Here we explore the effect of a daytime nap on memory consolidation in a sample of preschool children. DESIGN Subjects performed both a figures recognition task and a priming task, in order to differentiate effects on explicit and implicit memory. SETTING Nursery school. PARTICIPANTS Twenty-three children (mean age: 52.6 ± 8 mo; 13 males) participated in the study. INTERVENTION After a study phase in which children had to name 40 pictures of objects and animals, each subject either took an actigraphically monitored nap or stayed awake. At retest, children were administered both an implicit and an explicit memory task. MEASUREMENTS AND RESULTS The implicit memory task consisted of naming 40 pictures presented at eight ascending levels of spatial filtering. The explicit memory task consisted of judging 40 pictures as old or new. The number of correct answers at the explicit recognition task was significantly higher in the nap compared to the wake condition, whereas priming effects did not differ between conditions. CONCLUSIONS A positive role of sleep in explicit memory consolidation, similar to the one observed in the adult, was detected in our sample of preschool children. In contrast, our data suggest that implicit perceptual learning, involved in priming tasks, does not benefit from sleep.

Schooltime subjective sleepiness and performance in Italian primary school children

ABSTRACT Despite its clinical importance, the issue of the diurnal time course of sleepiness and performance in children remains largely unexplored. The objective of this study is to draw a profile of daytime subjective sleepiness and performance, at simple and complex tasks, in a cohort of Italian primary school children.To this aim, a sample of 316 children (age range: 5–11 years; mean 8.2 ± 1.5) was recruited and sub-divided into three groups, according to age: Group 1 (5–7 years; N = 127), Group 2 (8–9 years; N = 108), Group 3 (10–11 years; N = 81). Subjective sleepiness and simple performance were evaluated, respectively, through the Pictorial Sleepiness Scale and the Simple Reaction Time Task. Executive functions were addressed by means of the “Go/No-Go Task.” Measurements were made in the children’s class three times a day, one day a week over a 3-week period in order to reliably reflect the habitual time course of sleepiness and performance, within the following time intervals: a) 8:30 am–10:30 am; b) 11 am–1 pm; c) 2 pm–4 pm.For the global sample, a significant increase of subjective sleepiness was found at the end of school day (2–4 pm), although at relatively low levels. No significant differences were observed in reaction times across the day, whereas a significant worsening was detected in performance at complex task already since mid-morning. Significant correlations were found between subjective sleepiness and complex performance at all points.Slight age-related differences were found in the time courses of subjective sleepiness: in fact, a significant overday reduction of vigilance levels, from mid-morning onwards, was observed in children aged 5–9 years, but not in the older children (10–11 years). However, the daily time course of both simple and complex performances did not differ among children of the three age groups. Our results show changes in vigilance and cognitive functions across a typical school day in childhood, as well as age-related differences in sleepiness profile, that we suggest to thoroughly consider when conceiving chronopsychological interventions in the school context.

Systemic oxidative stress in the Congenital Central Hypoventilation Syndrome

Congenital central hypoventilation syndrome (CCHS), also known as Ondines curse, is a rare disorder characterised by severe hypoventilation during sleep and autonomic dysregulation [1, 2]. The incidence of CCHS is about one in 200 000 live births. In >90% of cases, polyalanine repeat expansion mutations are present in the paired-like homeobox PHOX2B gene, although a frameshift variant may also be found [3]. The PHOX2B gene encodes a highly conserved homeobox domain transcription factor that plays a regulatory role in the differentiation of the motor neuron and the serotonergic neuronal fate in the development of the central nervous system [4]. The hallmark of CCHS is the “forgotten breathing”, which implies the need for life-long mechanical ventilation during sleep. However, in more severe cases characterised by global hypoventilation, mechanical ventilation must also be extended during wakefulness. Ventilatory support may be provided by tracheostomy and assisted ventilation, noninvasive ventilation or diaphragm pacemakers. Severe respiratory depression typically arises at birth but in milder cases, CCHS may be diagnosed later on in childhood or adulthood (later-onset CCHS) [1, 2]. This study is the first to demonstrate an increase in ROS in CCHS patients. This implies that therapeutic strategies based on antioxidants should be taken in consideration and the mechanisms provoking the increase of ROS should be clarified. http://ow.ly/5Rhp30lJ7Yi

The Effect of Cognitive Activity on Sleep Maintenance in a Subsequent Daytime Nap

ABSTRACT Background/Objective: The aim of this study is to assess the effects of a learning task on the characteristics of a subsequent daytime nap. Participants and Methods: Thirty-eight subjects were administered a control nap (C) and one preceded by a cognitive training session (TR). Results: Relative to C, TR naps showed significantly increased sleep duration with decreased sleep latency, as well as significantly increased sleep efficiency due to reduced awakening frequency. Meaningful trends were also found toward an increase of Stage 2 sleep proportion and a reduction of Stage 1 sleep, percentage of wake after sleep onset (WASO), and frequency of state transitions. Conclusions: Our results indicate that presleep learning favors sleep propensity and maintenance, offering the possibility to explore planned cognitive training as a low-cost treatment for sleep impairments.

Priming recognition in good sleepers and in insomniacs

Insomniacs often report memory and concentration problems, but these complaints have not been consistently supported by performance measurements. Furthermore, while the majority of studies have addressed explicit memory, few have investigated the implicit domain, and very little is known concerning other types of implicit memory besides procedural memory, such as priming. Thus, the purpose of the study was to investigate priming effect for visual stimuli in insomniacs and good sleepers. Twenty‐three insomniacs and 20 good sleepers performed a visual priming task in which they were asked to name new and old pictures presented at nine ascending levels of spatial filtering. Both neutral and sleep‐related stimuli were used, as previous research evidenced an attentional bias for sleep‐related stimuli. Visual priming effect was observed in both groups, suggesting that poor sleep quality does not affect this type of implicit memory. However, the identification process in insomniacs is influenced by the nature of the stimulus to identify: insomniacs recognized both new and old sleep‐related stimuli at lower spatial frequencies compared with good sleepers. The tendency to selectively attend to sleep‐related stimuli may influence top‐down processes occurring during identification of filtering stimuli, by determining a pre‐allocation of attentional resources and facilitating identification processes even when sensorial information is scant. Differences in the identification processes of sleep‐related stimuli compared with neutral ones should be carefully taken into account as possible pre‐clinical markers of insomnia in poor sleepers.

Apparent Life-Threatening Events (ALTE): Italian guidelines

Five years after the first edition, we have revised and updated the guidelines, re-examining the queries and relative recommendations, expanding the issues addressed with the introduction of a new entity, recently proposed by the American Academy of Pediatrics: BRUE, an acronym for Brief Resolved Unexplained Events. In this manuscript we will use the term BRUE only to refer to mild, idiopathic cases rather than simply replace the acronym ALTE per se.In our guidelines the acronym ALTE is used for severe cases that are unexplainable after the first and second level examinations.Although the term ALTE can be used to describe the common symptoms at the onset, whenever the aetiology is ascertained, the final diagnosis may be better specified as seizures, gastroesophageal reflux, infection, arrhythmia, etc. Lastly, we have addressed the emerging problem of the so-called Sudden Unexpected Postnatal Collapse (SUPC), that might be considered as a severe ALTE occurring in the first week of life.