Smartphone ownership increased dramatically during the last decade and reached already over 80% by today. However, the screens from these devices emit high portions of short-wavelength light, which is known to increase alertness and to affect circadian rhythmicity. Since especially adolescents and young adults use their smartphones and other media devices also in the late evening hours shortly before bedtime, it is of importance to assess the effects of this short-wavelength light exposure during that time-period. There is still a lack of agreeing and ecologically valid evidence on how blue light filters might influence the alerting effects of evening short-wavelength light. Therefore, in this study, we present data from a within-subjects crossover design in which the participants (N = 28, 18-25yrs) spent three nights in the sleep laboratory and had to read for 90 min before bedtime either on a smartphone (1) with or (2) without a blue light filter, or (3) on printed material. Subjective sleepiness was not affected by the reading conditions. However, objective alertness levels, derived from an auditory GO/NOGO task, indicated a decrease in performance in the next-morning which was only present in the smartphone condition without a blue light filter. Potential explanations for the lack of an evening effect on alertness levels are discussed by assessing the physiological EEG data during the evening. However, the next-morning results already indicate a protective effect of the blue light filtering software that could maybe be explained by a protective effect on sleep.
|Online-Konferenz||Salzburg Mind-Brain Annual Meeting (SAMBA) 2021|
|Zeitraum||15/07/21 → 16/07/21|