Introduction
sleepiness, photosensitive, Alertness
RETINA
Alertness is a prerequisite for attention, represents a general sensitivity to incoming stimuli (external or internal)Light exposure of rods and cones is necessary for visual perception (CIE 086: 1990). However, the human retina contains another photoreceptor type (i.e., intrinsic photosensitive ganglion cells, ipRGCs), that projects photic information directly to brain areas not associated with visionThere is strong evidence for non-visual light effects during the night (see, e.g.,Typically, non-visual light effects are generated by continuous exposure to specific light settings. Another promising approach is exposure to intermittent lightThe present study primarily aimed at investigating the acute effects of repeated exposure to two bright white light pulses with different light doses on attentional parameters on two separate days in a simulated office environment. To avoid a reduction in visual comfort and performance, as highlighted in studies of dynamic workplace lightingIn line with the review by Xu et al.A second measure was complex attentional performance. The task had to be performed after the simple attention task at two constant, strongly different corneal illuminances (1360 lx and 130 lx at eye level, respectively). Again, we hypothesized that reaction speed in the complex attention task would increase at the higher corneal illuminance.Polyvagal theory emphasizes the importance of autonomic parasympathetic activity for cognitive functions and especially for attentional processesWe also hypothesized that subjective sleepiness would decrease after exposure to a bright light pulse.