SCREENS: Sleep, Circadian Rhythms, and Electronics in the EveNing Study

Circadian phase can be examined by measuring the circadian timing of melatonin onset under dim light conditions (dim light melatonin onset; DMLO). Following established procedures with children, salivary DLMO will be collected under dim light conditions (<5 lux), via a cheek swab every 30-60 minutes beginning 5 hours prior to and ending 1-hour following typical bedtime. Saliva samples will be centrifuged, frozen, and assayed using radioimmunoassay test kits by Solid Phase in Portland Me. DLMO phase will be determined using linear interpolation across the time points before and after melatonin concentration increased to and remained above 4pg/mL. We will examine differences in the change from night 8 to night 10 and the change from night 15 to night 17.

Children will wear an Actiwatch Spectrum watch (Philips Respironics, Inc.) on the wrist of their non-dominant hand. Sleep latency (i.e., the time between when they child starts to try to fall asleep as indicated by a push of the event marker button on the Actiwatch and when the child falls asleep (first 3 consecutive epochs of sleep).

Heart rate (HR) will be assessed using a Polar H10 HR monitor which integrates with the Actigraph GT3X-BT devices to record HR data from which raw data can be extracted. The Polar H10 HR monitor will be worn on a chest strap fitted to the child according to manufacturer guidelines during the 1-hour experimental and internal negative exposures.

Heart rate variability (HRV) will be assessed using a Polar H10 HR monitor which integrates with the Actigraph GT3X-BT devices to record HR data from which raw data can be extracted. The Polar H10 HR monitor will be worn on a chest strap fitted to the child according to manufacturer guidelines during the 1-hour experimental and internal negative exposures.

the Pre-Sleep Arousal Scale for Children (PSAS-C) will be used to assess Children's subjective report of arousal prior to sleep on Night 2. The PSAS-C contains 16 items comprising 2 subscales assessing somatic and cognitive arousal and demonstrated high internal consistency. Items are scored on a Likert scale from 1 to 5 with scores ranging from 16 to 80. Higher scores indicate greater pre-sleep arousal.

The Pictorial Sleepiness Scale is a measure of perceived sleepiness in a given moment that has been validated with individuals 4- to 73-years of age, demonstrating a strong correlation with the Karolinska Sleepiness Scale (r=.72) and the Sandford Sleepiness Scale(r=.94). The use of cartoon faces facilitates the assessment of sleepiness in population with minimal literacy skills. Almost all participants (99%) correctly ranked the faces in order of sleepiness. Children will complete the sleepiness scale before the start of the experimental condition (~60 minute prior to bedtime), 30 minutes later, and again at bedtime.

To assess objective emotion regulation in the home on Day 3, we will use a modified version the Trier Social Stress Test (TSST), The task will begin with a 5-min baseline segment, during which children will be asked to relax while they listen to a recording of nature sounds (i.e., waves at the beach) in order to collect resting HR and HRV). After this baseline period, children will then engage in a task in which they To assess objective emotion regulation in the home on Day 3, we will use a modified version the Trier Social Stress Test (TSST), The task will begin with a 5- min baseline segment, during which children will be asked to relax while they listen to a recording of nature sounds (i.e., waves at the beach) in order to collect resting HR and HRV). After this baseline period, children will then engage in a task in which they imagine they are giving a speech in front of a class of 20 kids they have never met. Resting and task-based HR and HRV data will be collected.

Subjective reports of emotional arousal and regulation will also be collected before and after the 5-minute speech task. Children will provide ratings of arousal using the Self-Assessment Manikin (SAM), a widely-used non-verbal pictorial scale that measures arousal associated with a person's affective reaction to a wide variety of situations and stimuli. Emotion regulation will be assessed via a likert-type rating requiring children to indicate how difficult it was to regulate (control) their emotions during the speech task, from ) (not hard at all) to 10 (very hard).

Letter-number sequencing Test (WISC-V) asks children to listen to lists of letters and digits and repeat the letters back in alphabetical order, and the digits in ascending numerical order, with the lists increasing in length from 2-8 alphanumeric characters throughout the test. Children will be read three different alphanumeric series for each list lengths, and one point will be awarded for each correct recall, for a total of 21 points. This performance score will be used as a measure of working memory.

The Color-Word Interference Test (D-KEFS) is a standard "Stroop-like" task. Across the two tasks, inhibition and inhibition switching, completion time and errors (4 indicators in total) are used as markers of inhibitory control. The inhibition task is a standard "Stroop-like" task. During inhibition switching, participants also encounter words in colored ink wherein they say the color and inhibit reading the work. However, during some trials, words are enclosed by a box wherein the participant needs to switch to reading, not naming, the color in which it is printed.

Assesses vigilant attention (reaction time to changes in visual stimuli) and is sensitive to changes in sleep.