Odile Rohmer

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. Arousal responsiveness increased with sound level. It was the highest in S2 and the lowest in REM sleep. Micro-arousals (3-10 s) occurred at a rate of 25-30%, irrespective of the type of train. 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.

Social Judgment of People with a Disability in the Workplace: How to Make a Good Impression on Employers

This research investigates the social judgment of people with a disability in a professional context. In Study 1, participants without a disability were asked to rate people with a disability on scales measuring competence and warmth. In Study 2 individuals with and without a disability were asked to present themselves in such a way as to make the best possible impression on a potential employer. In a second round, they were asked to make the best possible impression assuming that they had (or did not have) a disability. As predicted, people with a disability were systematically presented as warm, but incompetent. This evaluation was observed in groups of people with and in those without a disability.

INTERACTION OF AGE WITH TIME OF DAY AND MENTAL LOAD IN DIFFERENT COGNITIVE TASKS

Extensive research has demonstrated that shiftwork produces deleterious effects on health because of the desynchrony it induces in the biological clock. The problem is even more crucial for older workers who present, in addition, various decrements in their cognitive functioning, particularly on attention and memory. The present study assessed whether age was related to task complexity as a function of time of day and time-on-task in a rapid rotating work-rest schedule. 24 subjects (12 juniors: 20–30 years and 12 seniors: 50–60 years) performed either a simple task (visual discrimination) or a complex task (descending subtraction) on three different moments of the day simulating the main shifts (morning, evening, and night). Analysis indicated that an age effect was only present on the more complex task, which was demanding in attentional resources and memory load. Seniors had no deficit in performance on the simple task compared to juniors. The effect of time of day was restricted to the simple task for both age groups. However, some differential strategies appear to distinguish juniors and seniors, specifically on accuracy during the night, suggesting that subjects of different ages cope with cognitive tasks in different ways and that perhaps some adverse effects apparently associated with aging could be counteracted by efficient strategies, but not others.

Implicit measures of the stereotype content associated with disability

The present research aimed to show that the mixed stereotype content of persons with disability observed at an explicit level does not manifest itself using implicit measures. Two experimental studies were conducted to analyse the stereotype content of persons with a disability at the implicit level. The procedure used in this study was the concept priming paradigm. Furthermore, Study 2 also included an explicit measure. Results show important discrepancies between implicit and explicit measures. At an explicit level, previous work supporting the mixed stereotype content of persons with disability was replicated: participants judged these persons as warmer but less competent than persons without a disability. At an implicit level, a quite different pattern of results emerged: persons with a disability were associated not only with less competence than persons without disability, but also with less warmth. These findings suggest that the mixed pattern between warmth and competence generally observed at an explicit level may be based on societal pressures against prejudice and discrimination.

Living alongside railway tracks: Long-term effects of nocturnal noise on sleep and cardiovascular reactivity as a function of age

Very few studies were devoted to permanent effects of nocturnal railway noise on sleep and cardiovascular reactivity. We investigated the effects of nocturnal railway noise on sleep and cardiovascular response in young and middle-aged adults living for many years either near a railway track or in a quiet area. Forty subjects (50% males) divided into two age groups (juniors: 26.2+/-3.6 and seniors: 56.2+/-4.2) participated in this experiment. Half of them lived near a railway track (RW group: 2.6 to 19 years) and the other half in a quiet environment (QE group: 8.1 to 14.2 years). After an adaptation night, all subjects underwent two nights in the laboratory: one control night and one noisy night (30 by-passes of a freight train). Sleep and cardiovascular modifications were assessed in response to noise. Sleep fragmentation indices were lower in RW subjects compared to QE whatever their age. In response to noise, there was a higher cardiovascular response rate to noise in RW juniors and a lower cardiovascular response rate in RW seniors compared to their age-paired QE counterparts. In conclusion, permanent exposure to nocturnal railway noise leads to decreased sleep fragmentation and to cardiovascular habituation. It is suggested that during the initial period experienced by residents living near railway tracks, nocturnal railway noise could induce a sensitization process on the autonomic response to noise reflecting a startle/defense reflex due to its functional significance, which progressively turns to habituation in the long-term if no adverse effect is experienced.

Effects of acute and chronic sleep deprivation on daytime alertness and cognitive performance of healthy snorers and non-snorers

BACKGROUND Respiratory events during sleep usually lead to micro arousals resulting in consecutive daytime sleepiness even in healthy snorers. The present study investigated the evolution of subjective and objective daytime sleepiness and reaction time in healthy snorers submitted to acute and chronic sleep deprivation. METHODS Objective sleepiness was measured by the MSLT, subjective sleepiness by the Karolinska Sleepiness Scale (KSS), and reaction time (RT) by the Psychomotor Vigilance Test. Mean sleep latencies, KSS scores and performance were analyzed through repeated measures ANOVAs with one between-factor (snorers and non-snorers) and two within-factors (sleep deprivation [baseline, acute, and chronic sleep deprivation] and time-of-day). RESULTS The findings reveal that sleep deprivation does not enhance snoring but that, during baseline, objective daytime sleepiness is higher in snorers than in non-snorers (shorter sleep latencies) with no difference in subjective assessments. The effects of acute and chronic sleep deprivation on sleep are similar in both groups, but, after acute sleep deprivation, RT and attentional lapses (RT >500 ms) are higher in snorers. Chronic sleep deprivation produces similar results in both groups. CONCLUSION These results suggest that respiratory efforts may be involved in the increased vulnerability to sleep deprivation of healthy snorers when compared to non-snorers.

Le stéréotype des personnes handicapées en fonction de la nature de la déficience Une application des modèles de la bi-dimensionnalité du jugement social

EnglishThe present research concerns the stereotypes associated with subgroups of persons with disability. Building on the ambivalent nature of social judgment (Dubois & Beauvois, 2008 ; Fiske, Cuddy, Glick & Xu, 2002), we assessed the degree to which participants without disability (N = 210) differentiate among particular disability subgroups on scales reflecting personality traits. A principal-components analysis revealed that social judgment centers on three distinguishable factors: the two fundamental dimensions traditionally found, i.e. warmth and competence, and a third dimension, that we labelled courage. Results suggest that persons with disability are seen as less competent, but more warm and courageous than persons without disability. Moreover, we showed that people conceptualize disability at two levels: mental and physical disability. Persons with mental disability are viewed as less competent and less courageous than persons with physical disability. Implications of these stereotypes for understanding discriminatory behaviors against persons with disability are discussed. francaisEn s�appuyant sur les modeles recents de la bi-dimensionnalite du jugement social (Dubois & Beauvois, 2008 ; Fiske, Cuddy, Glick & Xu, 2002), l�objectif de cette etude est d�analyser le stereotype associe aux differents sous-groupes de personnes en situation de handicap. 210 etudiants ont evalue differents sous groupes de personnes handicapees, a partir de traits de personnalite. Au-dela des dimensions d�agreabilite et competence classiquement relevees dans la litterature, nos resultats font apparaitre une troisieme dimension, celle du courage. Les comparaisons de moyennes montrent que les personnes handicapees sont jugees moins competentes, mais plus agreables et plus courageuses que les personnes sans handicap. Par ailleurs, il apparait que le handicap est subdivise en deux categories : le handicap physique et le handicap mental. Les personnes avec un handicap mental sont percues moins competentes et moins courageuses que celles avec un handicap physique.

Are OSAS patients impaired in their driving ability on a circuit with medium traffic density

OBJECTIVES Many studies have demonstrated that patients with Obstructive Sleep Apnea Syndrome (OSAS), a very common sleep-related breathing disorder, are usually impaired in their driving ability because of decreased sleep quality. However, most of the simulation procedures in laboratories are designed to create monotonic conditions with low traffic density, if any, thereby leading to a dramatic decrease in performance in OSAS patients because of the lack of stimulation. The aim of this study was therefore to evaluate driving abilities in OSAS patients involved in a driving simulation task with medium traffic density, in order to replicate as far as possible real world conditions. The behavioral and physiological attributes likely to predict driving performance in these patients were also investigated. METHODS After a normal night of sleep, 12 OSAS patients and 8 healthy controls performed 6 driving sessions during a 24-h period of sustained wakefulness. Driving performances (speed, lateral position, distances...) were measured and correlated to sleep parameters and to a waking EEG recorded during the task. RESULTS Compared to controls, patients showed difficulties in speed adjustment. However, they maintained longer inter-vehicle distances, including during overtaking. Their waking EEG, while driving, showed increased spectral power in theta (3.9-7.8Hz) but also in beta (12.7-29.2Hz) activity, alpha power (7.9-12.6Hz) being increased in both groups due to sustained wakefulness. Poor sleep indices were correlated to increased theta and beta activities, as well as to more cautious behavior. DISCUSSION In medium traffic density conditions, driving performance in OSAS patients remained at near normal levels, but with more cautious behavior than controls. This could be the result of a bigger effort to stay awake, as suggested by an increased beta activity in these patients.

Les travailleurs handicapés sont-ils perçus comme des travailleurs compétents ?

Resume En reference aux modeles actuels dans le domaine du jugement social, l’objectif de ce travail est d’analyser l’image des personnes en situation de handicap dans le monde du travail. Dans trois etudes, les participants (valides) devaient evaluer des personnes avec ou sans handicap, qui travaillent ou non, sur des traits refletant les principales dimensions du jugement social (desirabilite sociale et utilite sociale). Les resultats ont montre que les personnes avec handicap sont systematiquement jugees moins utiles, mais plus desirables que les personnes sans handicap. Concernant plus specifiquement l’utilite sociale, les personnes avec handicap etaient considerees moins competentes, mais plus courageuses que les personnes sans handicap. Ces resultats sont discutes en reference a la valeur economique des personnes en situation de handicap.

Combined Effects of Noise and Shift Work on Fatigue as a Function of Age

The study was conducted to analyse possible interactions between noise and shift work on fatigue as a function of age. In a large questionnaire survey, we assessed personal and environmental risk factors related to fatigue. Noise exposure at work (LAeq, 8hr) was measured with personal noise dosimetry. The sample included 254 day and shift workers, and was divided into 2 age groups (<40- and >40-year-olds). Noise exposure had a main effect on fatigue. The highest noise exposure resulted in an increase in the fatigue level of older shift workers. The quantity of sleep mainly depended on the type of shift and age. Our data suggest that the most important factor generating fatigue could be related to industrial noise exposure, a factor which seems to aggravate work-related fatigue generated in a synergic manner by shift work and ageing. Senior workers should be prevented from cumulating those occupational stressors.