Short-term mindfulness practice attenuates reward prediction errors signals in the brain

Activity changes in dopaminergic neurons encode the ongoing discrepancy between expected and actual value of a stimulus, providing a teaching signal for a reward prediction process. Previous work comparing a cohort of long-term Zen meditators to controls demonstrated an attenuation of reward prediction signals to appetitive reward in the striatum. Using a cross-commodity design encompassing primary- and secondary-reward conditioning experiments, the present study asks the question of whether reward prediction signals are causally altered by mindfulness training in naive subjects. Volunteers were randomly assigned to 8 weeks of mindfulness training (MT), active control training (CT), or a one-time mindfulness induction group (MI). We observed a decreased response to positive prediction errors in the putamen in the MT group compared to CT using both a primary and a secondary-reward experiment. Furthermore, the posterior insula showed greater activation to primary rewards, independently of their predictability, in the MT group, relative to CT and MI group. These results support the notion that increased attention to the present moment and its interoceptive features - a core component of mindfulness practice - may reduce predictability effects in reward processing, without dampening (in fact, enhancing) the response to the actual delivery of the stimulus

Interaction of smoking and occupational noise exposure on hearing loss: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Noise is the most common hazardous agent at workplaces. Noise induced hearing loss (NIHL) has been known since the industrial revolution. Although NIHL is permanent, irreversible and frequent, it is preventable. The economic costs of NIHL have been estimated to be about billions of dollars. Besides, cigarette smoking is a common habit worldwide, and according to some recent studies smoking and noise may act in common causal pathways for hearing loss.</p> <p>Methods</p> <p>A cross-sectional study was designed to study the effect of smoking on NIHL in 206 male smoker workers and 206 male non-smoker workers in a large food-producing factory, in which workers were exposed to noise levels exceeding 85dBA. To determine noise exposure level, we used sound level measurements reported by industrial hygienists.</p> <p>A qualified audiologist assessed hearing acuity by using standardized audiometric procedures assuring at least 14 h of noise avoidance.</p> <p>Results</p> <p>We observed that the percentage of workers with hearing threshold differences of greater than or equal to 30 dB between 4000 Hz and 1000 Hz in both ears were 49.5% and 11.2% in smoker and non smoker groups, respectively (Odds ratio = 7.8, 95% CI = 4.7 – 13), and the percentage of workers with a hearing threshold of greater than 25dB at 4000 Hz in the better ear were 63.6% and 18.4% in smoker and non smoker groups, respectively. This difference was statistically significant after adjustment for age and exposure duration.</p> <p>Conclusion</p> <p>It can be concluded that smoking can accelerate noise induced hearing loss, but more research is needed to understand the underlying mechanisms. Accurate follow up of smoker workers who are exposed to noise levels exceeding 85 dBA is suggested. Smokers should periodically attend educational courses on "smoking cessation", especially in noisy workplaces.</p

Cost-effectiveness of a vocational enablement protocol for employees with hearing impairment; design of a randomized controlled trial

Background: Hearing impairment at the workplace, and the resulting psychosocial problems are a major health problem with substantial costs for employees, companies, and society. Therefore, it is important to develop interventions to support hearing impaired employees. The objective of this article is to describe the design of a randomized controlled trial evaluating the (cost-) effectiveness of a Vocational Enablement Protocol (VEP) compared with usual care. Methods/Design. Participants will be selected with the 'Hearing and Distress Screener'. The study population will consist of 160 hearing impaired employees. The VEP intervention group will be compared with usual care. The VEP integrated care programme consists of a multidisciplinary assessment of auditory function, work demands, and personal characteristics. The goal of the intervention is to facilitate participation in work. The primary outcome measure of the study is 'need for recovery after work'. Secondary outcome measures are coping with hearing impairment, distress, self-efficacy, psychosocial workload, job control, general health status, sick leave, work productivity, and health care use. Outcome measures will be assessed by questionnaires at baseline, and 3, 6, 9, and 12 months after baseline. The economic evaluation will be performed from both a societal and a company perspective. A process evaluation will also be performed. Discussion. Interventions addressing occupational difficulties of hearing impaired employees are rare but highly needed. If the VEP integrated care programme proves to be (cost-) effective, the intervention can have an impact on the well-being of hearing impaired employees, and thereby, on the costs for the company as well for the society. Trial registration. Netherlands Trial Register (NTR): NTR2782. © 2012 Gussenhoven et al; BioMed Central Ltd

Modulation of Brain Activity during Action Observation: Influence of Perspective, Transitivity and Meaningfulness

The coupling process between observed and performed actions is thought to be performed by a fronto-parietal perception-action system including regions of the inferior frontal gyrus and the inferior parietal lobule. When investigating the influence of the movements' characteristics on this process, most research on action observation has focused on only one particular variable even though the type of movements we observe can vary on several levels. By manipulating the visual perspective, transitivity and meaningfulness of observed movements in a functional magnetic resonance imaging study we aimed at investigating how the type of movements and the visual perspective can modulate brain activity during action observation in healthy individuals. Importantly, we used an active observation task where participants had to subsequently execute or imagine the observed movements. Our results show that the fronto-parietal regions of the perception action system were mostly recruited during the observation of meaningless actions while visual perspective had little influence on the activity within the perception-action system. Simultaneous investigation of several sources of modulation during active action observation is probably an approach that could lead to a greater ecological comprehension of this important sensorimotor process

A survey of acoustic conditions and noise levels in secondary school classrooms in England

An acoustic survey of secondary schools in England has been undertaken. Room acoustic parameters and background noise levels were measured in 185 unoccupied spaces in 13 schools to provide information on the typical acoustic environment of secondary schools. The unoccupied acoustic and noise data were correlated with various physical characteristics of the spaces. Room height and the amount of glazing were related to the unoccupied reverberation time and therefore need to be controlled to reduce reverberation to suitable levels for teaching and learning. Further analysis of the unoccupied data showed that the introduction of legislation relating to school acoustics in England and Wales in 2003 approximately doubled the number of school spaces complying with current standards. Noise levels were also measured during 274 lessons to examine typical levels generated during teaching activities in secondary schools and to investigate the influence of acoustic design on working noise levels in the classroom. Comparison of unoccupied and occupied data showed that unoccupied acoustic conditions affect the noise levels occurring during lessons. They were also related to the time spent in disruption to the lessons (e.g., students talking or shouting) and so may also have an impact upon student behavior in the classroom

EXPOSITION AUX BRUITS IMPULSIONNELS EN MILIEUX DE TRAVAIL : LA PROTECTION ASSURÉE PAR LES DISPOSITIONS RÈGLEMENTAIRES EST-ELLE SUFFISANTE ?

Les réglementations nationales en matière d'exposition professionnelle aux bruits de type impulsionnel présentent des différences importantes. Certaines prennent en compte quelques paramètres physiques, tels que le niveau crête et le nombre d'impulsions alors que d'autres considèrent le cumul d'énergie sonore ponderée A. Au cours des dix dernières années, le Groupe d'Acoustique de l'Université de Montréal (GAUM) a cumulé des données expérimentales auprès de sujets humains exposés à des bruits impulsionnels qui variaient en fonction du niveau de pression acoustique de crête, du nombre d'impulsions, du contenu spectral et de la durée de décroissance. Des sous-estimations atteignant 30 dB ont été notées entre les données expérimentales et les limites admissibles définies par les diverses réglementations. Un critère de nocivité provisoire est élaboré en intégrant les résultats des études expérimentales faites auprès de sujets humains. Le critère tient compte du niveau d'exposition sonore (SEL), de la pression de crête, de la durée de décroissance, du contenu spectral et du nombre d'impulsions.National regulations concerning exposures to impulse noise in workplaces differ largely from one country to another. Some regulations only take into account a few physical parameters such as peak level and number of impulses whereas others are based on an A weighted energy dose (LAeq,8h). During the last ten years, the GAUM has cumulated experimental data on human subjects exposed to impulse noise which varies in peak level, number of impulses, spectral content and decay time. Under-estimations reaching 30 dB have been found between experimental data and admissible limits by certain regulations. A damage risk criterion has been elaborated based on experimental data. This criterion takes into account sound exposure level (SEL), peak level, decay time, spectral content and number of impulses

APPLICATION D'UN MODÈLE DE DÉTECTION D'AVERTISSEURS SONORES EN MILIEUX DE TRAVAIL BRUYANTS

Le Groupe d'Acoustique de l'Université de Montréal (GAUM) a développé un modèle informatisé ("Détectson") qui permet de prédire les capacités de détection d'avertisseurs sonores de danger par les travailleurs en milieu bruyant. Le logiciel a été utilisé pour évaluer 93 conditions d'utilisation de ce type de signaux dans une acierie. Dans plus de la moitié des cas, les signaux ne rencontrent pas les critères minima pour assurer leur reconnaissance par des travailleurs âgés entre 20 et 60 ans. Une version conviviale du logiciel sera bientôt disponible. Cet outil pratique permettra de corriger les situations problématiques et de concevoir des signaux adéquats.The Groupe d'Acoustique de l'Université de Montréal (GAUM) has developped a computerized model ("Detectsound") for the detection of warning sounds by workers in noisy environments. The program was used to analyse 93 different configurations of warning signals in a steel plant. In more than half of the cases, the warning signals did not meet the recognition criteria for workers aged between 20 and 60. A "user friendly" version of the program will be soon available. This practical tool will allow to improve and to design safer existing signals