International journal of psychophysiology : official journal of the International Organization of Psychophysiology
-
Int J Psychophysiol · Dec 2008
Effects of nocturnal railway noise on sleep fragmentation in young and middle-aged subjects as a function of type of train and sound level.
Due to undisputable effects of noise on sleep structure, especially in terms of sleep fragmentation, the expected development of railway transportation in the next few years might represent a potential risk factor for people living alongside the rail tracks. The aim of this study was to compare the effects of different types of train (freight, automotive, passenger) on arousal from sleep and to determine any differential impact as a function of sound level and age. Twenty young (16 women, 4 men; 25.8 years+/-2.6) and 18 middle-aged (15 women, 3 men; 52.2 years+/-2.5) healthy subjects participated in three whole-night polysomnographic recordings including one control night (35 dBA), and two noisy nights with equivalent noise levels of 40 or 50 dB(A), respectively. ⋯ Awakenings (>10 s) were produced more frequently by freight train than by automotive and passenger trains. Normal age-related changes in sleep were observed, but they were not aggravated by railway noise, thus questioning whether older persons are less sensitive to noise during sleep. These evidences led to the conclusion that microscopic detection of sleep fragmentation may provide advantageous information on sleep disturbances caused by environmental noises.
-
Int J Psychophysiol · Dec 2008
You can see pain in the eye: pupillometry as an index of pain intensity under different luminance conditions.
Pupil dilation is regulated autonomically and it may be a valid measure of pain, but pupillometry for pain intensity recordings has not been evaluated under different luminance conditions. We hypothesized that the pupil response may serve as an objective indicator of pain intensity even if luminance conditions differ which is often the case in experiments with pictures. In 20 healthy females we applied a tonic pressure pain to the fingers (20 s). ⋯ While this maximum pupil dilation did not differ with pressure intensity, the pupil dilation was larger for the higher pressure intensity in the period from 10 s after pressure onset to pressure offset. Even under different luminance conditions, pupillometry can serve as an objective indicator of pressure pain intensity. Thus, it seems promising to use pupillometry with complex experimental designs combining pain and pictorial stimuli.