Interindividual variabilities in cognitive performance degradation after alcohol consuption and sleep loss are related

Introduction The sleep inducing effects of alcohol as well as the increase in sleep propensity and sleepiness after sleep loss have been linked to the adenosinergic system in the brain. While the performance impairing effects of ethanol have partly been related to the inhibitory effects of cerebral adenosine, sleep loss has been found to increase adenosine receptor density. The interindividual variability of cognitive performance impairments after alcohol intake as well as after sleep loss is extensive. Thus, we examined in humans whether performance degradations resulting from sleep loss and alcohol consumption are related. Methods Performance in a 10-min Psychomotor Vigilance Task (PVT) was tested in 47 healthy volunteers (mean age 27 ± 5 (SD) years, 21 females) at 6 pm 1) after an 8 hour control night, 2) after alcohol consumption (aiming at a blood alcohol concentration (BAC) of 0.08%), and 3) after 35 hours of total sleep deprivation. After alcohol intake, 35 of the participants reached a BAC of more than 0.06% prior to the performance testing (mean BAC 0.074%, SD 0.009%, min. 0.063%, max. 0.095%) and were included in the analyses. Two recovery nights were scheduled between conditions. Results Performance impairments due to acute alcohol intake and due to 35 hours of sustained wakefulness were calculated as differences from performance under control conditions. The degree in performance degradation correlated highly between both conditions (i.e. 10% slowest reaction times: Pearson’s r=0.73, p<0.0001; standard deviation of reaction times: r=0.75, p<0.0001; mean reaction time: r=0.59, p=0.0002). Conclusions Participants whose PVT performance proved to be vulnerable to the effects of alcohol consumption were also vulnerable to sleep loss, whereas individuals who were resilient against the effects of alcohol were also less susceptible to the impact of sleep deprivation. These results suggest that the effects of alcohol and sleep deprivation on performance are mediated – at least in part – by a common pathway that may involve the adenosinergic system in the brain

Residents’ negative attitude towards air traffic is associated with impaired objective sleep quality

Objectives: Nocturnal aircraft noise induces sleep disturbances and is associated with impaired quality of life. The magnitude of physiological and psychological responses to noise varies among individuals. Stable individual vulnerabilities have been reported for aircraft noise induced awakenings. To date it is unknown, whether the subjective attitude towards air traffic and residents' sleep quality impact on each other. Methods: Seventy-four out of 81 investigated residents around Frankfurt Airport (Germany) rated their attitude towards air traffic (from 1 = negative to 5 = positive; negative attitude: score ≤ 2, N=28, mean age 44 ± 16 years; moderate to positive attitude: score > 3, N=46, mean age 44 ± 15 years) and evaluated its necessity (from 1 = not necessary to 5 = highly necessary; no to moderate necessity: score ≤ 3, N=22, mean age 45 ± 10 years; high necessity: score > 3, N=52, mean age 43 ± 17 years). In addition, polysomnographical recordings were obtained in residents' home environment. These investigations were part of the NORAH sleep study in 2012. Results: Significant impairments in sleep quality (prolonged sleep onset latency, increased wake after sleep onset, reduced sleep efficiency, and less deep sleep) were found for participants with a negative attitude towards air traffic. The judgement of no or moderate necessity of air traffic was associated with a significantly reduced deep sleep duration. Conclusions: Residents' subjective attitude towards air traffic and their objective sleep quality are related. Cause and effect in this relationship remain to be identified

Impact Of Sleep Restriction And Recovery On Motivation During Repeated Cognitive Performance Testing

Introduction: Both motivation and sleep deprivation affect cognitive performance. Especially during long-lasting studies with repeated cognitive performance tasks there is concern that subjects will lose motivation over time. Results may be confounded due to changes in motivation. Methods: In an ongoing study, 29 healthy volunteers performed 55 cognitive performance tasks at three-hourly intervals in a 12-day inpatient study. After two baseline nights with 8 h time in bed (TIB) the intervention group (N=20; mean age 26 ± 4 years, 9 females) underwent chronic sleep restriction for 5 nights (5 h TIB) with a following recovery night of 8 h TIB. The control group (N=9; mean age 25 ± 5 years, 3 females) had the opportunity to sleep 8 hours every night. Participants completed the Karolinska Sleepiness Scale (KSS) and a questionnaire about their motivation (from 1=very little/not motivated to 5=very motivated) at 6 p.m. on all days. Results: Wilcoxon signed-rank tests showed a significant decrease in motivation (p=.0439) and a significant increase in subjective sleepiness (p=.0184) from baseline (motivation: 2.8 ± 0.6 (SD), sleepiness: 3.2 ± 1.2) to the last day of chronic sleep restriction (motivation: 2.2 ± 0.5, sleepiness: 5.1 ± 1.8) for the experimental group. Motivation remained low after recovery sleep (2.2 ± 0.8; p=.0198). Sleepiness and motivation scores showed a significant Spearman correlation (r=-0.43, p<0.001). Discussion: Chronic sleep restriction for five days leads to an increase in sleepiness and a decrease in motivation. One night of recovery is insufficient to reverse the motivation loss, contrasting with the beneficial effect on sleepiness. During chronic sleep restriction conditions subjective motivation seems to decrease as a function of subjective sleepiness

The Atlantic Ocean at the last glacial maximum: 1. Objective mapping of the GLAMAP sea-surface conditions

Recent efforts of the German paleoceanographic community have resulted in a unique data set of reconstructed sea-surface temperature for the Atlantic Ocean during the Last Glacial Maximum, plus estimates for the extents of glacial sea ice. Unlike prior attempts, the contributing research groups based their data on a common definition of the Last Glacial Maximum chronozone and used the same modern reference data for calibrating the different transfer techniques. Furthermore, the number of processed sediment cores was vastly increased. Thus the new data is a significant advance not only with respect to quality, but also to quantity. We integrate these new data and provide monthly data sets of global sea-surface temperature and ice cover, objectively interpolated onto a regular 1°x1° grid, suitable for forcing or validating numerical ocean and atmosphere models. This set is compared to an existing subjective interpolation of the same base data, in part by employing an ocean circulation model. For the latter purpose, we reconstruct sea surface salinity from the new temperature data and the available oxygen isotope measurements

Dissolved noble gases and stable isotopes as tracers of preferential fluid flow along faults in the Lower Rhine Embayment, Germany

Groundwater in shallow unconsolidated sedimentary aquifers close to the Bornheim fault in the Lower Rhine Embayment (LRE), Germany, has relatively low δ2H and δ18O values in comparison to regional modern groundwater recharge, and 4He concentrations up to 1.7 × 10−4 cm3 (STP) g–1 ± 2.2 % which is approximately four orders of magnitude higher than expected due to solubility equilibrium with the atmosphere. Groundwater age dating based on estimated in situ production and terrigenic flux of helium provides a groundwater residence time of ∼107 years. Although fluid exchange between the deep basal aquifer system and the upper aquifer layers is generally impeded by confining clay layers and lignite, this study’s geochemical data suggest, for the first time, that deep circulating fluids penetrate shallow aquifers in the locality of fault zones, implying  that sub-vertical fluid flow occurs along faults in the LRE. However, large hydraulic-head gradients observed across many faults suggest that they act as barriers to lateral groundwater flow. Therefore, the geochemical data reported here also substantiate a conduit-barrier model of fault-zone hydrogeology in unconsolidated sedimentary deposits, as well as corroborating the concept that faults in unconsolidated aquifer systems can act as loci for hydraulic connectivity between deep and shallow aquifers. The implications of fluid flow along faults in sedimentary basins worldwide are far reaching and of particular concern for carbon capture and storage (CCS) programmes, impacts of deep shale gas recovery for shallow groundwater aquifers, and nuclear waste storage sites where fault zones could act as potential leakage pathways for hazardous fluids

Influence of transient pressure changes on speech intelligibility: Implications for nextgeneration train travel

High-speed trains are operated in increasingly complex railway networks and continual improvement of driver assistance systems is necessary to maintain safety. Speech offers the opportunity to provide information to the driver without disrupting visual attention. However, it is not known whether the transient pressure changes inside trains passing through tunnels interfere with speech intelligibility. Our primary goal was to test whether the most severe pressure variations occurring in high-speed trains (25 hPa in 2 s) affect speech intelligibility in individuals with normal hearing ability and secondly whether a potential effect would depend on the direction of the pressure change. A cross-over design was used to compare speech intelligibility, measured with the monosyllable word test by Wallenberg and Kollmeier, in steady ambient pressure versus subsequent to pressure events, both realised in a pressure chamber. Since data for a power calculation did not exist, we conducted a pilot study with 20 participants to estimate variance of intra-individual differences. The upper 80% confidence limit guided sample size of the main campaign, which was performed with 72 participants to identify a 10% difference while limiting alpha (5%) and beta error (10%). On average, a participant understood 0.7 fewer words following a pressure change event compared to listening in steady ambient pressure. However, this intra-individual differences varied strongly between participants, standard deviation (SD) +/- 4.5 words, resulting in a negligible effect size of 0.1 and the Wilcoxon signed rank test (Z = -1.26; p = 0.21) did not distinguish it from chance. When comparing decreasing and increasing pressure events an average of 0.2 fewer words were understood (+/- 3.9 SD). The most severe pressure changes expected to occur in high-speed trains passing through tunnels do not interfere with speech intelligibility and are in itself not a risk factor for loss of verbal information transmission

Using network science to understand the aging lexicon: Linking individuals' experience, semantic networks, and cognitive performance

People undergo many idiosyncratic experiences throughout their lives that may contribute to individual differences in the size and structure of their knowledge representations. Ultimately, these can have important implications for individuals' cognitive performance. We review evidence that suggests a relationship between individual experiences, the size and structure of semantic representations, as well as individual and age differences in cognitive performance. We conclude that the extent to which experience‐dependent changes in semantic representations contribute to individual differences in cognitive aging remains unclear. To help fill this gap, we outline an empirical agenda that utilizes network analysis and involves the concurrent assessment of large‐scale semantic networks and cognitive performance in younger and older adults. We present preliminary data to establish the feasibility and limitations of such empirical, network‐analytical approaches

Data from the MySWOW proof-of-concept study: Linking individual semantic networks and cognitive performance

We report data from a proof-of-concept study involving the concurrent assessment of large-scale individual semantic networks and cognitive performance. The data include 10,800 free associations—collected using a dedicated web-based platform over the course of several weeks—and responses to several cognitive tasks, including verbal fluency, episodic memory, associative recall tasks, from four younger and four older native German speakers. The data are unique in scope and composition and shed light on individual and age-related differences in mental representations and their role in cognitive performance across the lifespan