The Goodnight Screen Media Study

Circadian phase can be examined by measuring the circadian timing of melatonin onset under dim light conditions (dim light melatonin onset; DMLO). Compared to markers of endogenous circadian rhythms, melatonin is relatively robust. Salivary DLMO measures have demonstrated high intraclass correlations (.93) with plasma and sensitivity and specificity comparable to plasma assays. Following established procedures with children, salivary DLMO will be collected on a in the laboratory 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.

Circadian phase can be examined by measuring the circadian timing of melatonin onset under dim light conditions (dim light melatonin onset; DMLO). Compared to markers of endogenous circadian rhythms, melatonin is relatively robust. Salivary DLMO measures have demonstrated high intraclass correlations (.93) with plasma and sensitivity and specificity comparable to plasma assays. Following established procedures with children, salivary DLMO will be collected on a in the laboratory 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.

Actigraphs (GT3X-BT, Pensacola, FL) worn on the wrist of the non dominant hand 24 hours a day for 4-5 days will measure sleep duration and timing of sleep onset and waking. Wrist placement reliably measures sleep duration. Sleep diaries will be completed. Monitor-wear logs will identify times the accelerometer is removed and the activity engaged in while the monitor is off.

Actigraphs (GT3X-BT, Pensacola, FL) worn on the wrist of the non dominant hand 24 hours a day for 4-5 days will measure sleep duration and timing of sleep onset and waking. Wrist placement reliably measures sleep duration. Sleep diaries will be completed. Monitor-wear logs will identify times the accelerometer is removed and the activity engaged in while the monitor is off.

Actigraphs (GT3X-BT, Pensacola, FL) worn on the wrist of the non dominant hand 24 hours a day for 4-5 days will measure sleep duration and timing of sleep onset and waking. Wrist placement reliably measures sleep duration. Sleep diaries will be completed. Monitor-wear logs will identify times the accelerometer is removed and the activity engaged in while the monitor is off.

Actigraphs (GT3X-BT, Pensacola, FL) worn on the wrist of the non dominant hand 24 hours a day for 4-5 days will measure sleep duration and timing of sleep onset and waking. Wrist placement reliably measures sleep duration. Sleep diaries will be completed. Monitor-wear logs will identify times the accelerometer is removed and the activity engaged in while the monitor is off.

Children's inhibitory control will be assessed using the Day/Night task. The order of this task will be counterbalanced across Day 14 and 21. This task can be used interchangeably with Grass/snow, so we will examine the difference in performance from the test administered on day 14 to the test administered on day 21.

Children's inhibitory control will be assessed using the Grass/Snow. The order of this task will be counterbalanced across Day 14 and 21. This task can be used interchangeably with Grass/snow, so we will examine the difference in performance from the test administered on day 14 to the test administered on day 21.

Children's Working Memory will be assessed using the Missing Scan assessment. This task will be administered at Day 14 and 21.

Children's Working Memory will be assessed using the Spin the Pots assessment. This task will be administered at Day 14 and 21.

The Head-Toes-Knees-Shoulder Task assesses both working memory and inhibitory control and will be administered on Day 14 and Day 21.

ActLumus devices containing a photocell will be used to assess ambient light exposure. Devices will be pinned to the shirt. ActLumus devices are capable of assessing light intensity and wavelength. Light exposure will be used as a covariate in analyses.

Children's tablet use on Android and iOS devices will be assessed during the study period. Daily screen use will be used as a covariate in the analysis. The Chronicle app will be used to assess the timing and amount of children's Android device use. Code developed by Arcascope will be used to assess the amount of children's iOS device usage.

The Chronicle and Acrascope data will be used to assess adherence to the evening tablet use conditions.

The Chronicle and Acrascope data will be used to assess adherence to the evening tablet use conditions.

Sleep hygiene will be assessed by parent report on the Children's Sleep Hygiene Scale. Contains 22 items. Response options are scored as follows: Never (1 point); Once in Awhile (2 points); Sometimes (3 points); Quite Often (4 points); Frequently, if not Always (5 points); Always (6 points). It contains 6 subscales that are computed by computing the mean of the items (each subscale could range from 1-6). The total score is computed by computing the mean of the subscales, with a potential range of 1-6. The total score will be used as the outcome of interest in the current study. Higher scores indicate better sleep hygiene practices.

Chronotype will be assessed by parent report of the child's preference for morningness or eveningness. The M/E score is calculated by adding items 17-26 (responses scored as a=1, b=2, c=3, d=4, d=5), except items 17,18,24,25 are reverse scored. the M/E score ranges from 10 (extreme morningness) to 49 (extreme eveningness). Morning types are defined as having a M/E scale score of ≤23, intermediate types: score of 24-32, and evening types: score ≥33.

Parents will be asked to report children's sleep behaviors and problems on the Child Sleep Habits Questionnaire. The total sleep disturbance score is comprised of 33 items. Response options are scored as Usually = 3; Sometimes = 2; and Never/Rarely = 1. Scores range from 33 to 99. Higher scores indicate more sleep problems.