The impact of stress and anxiety on the neurocognitive performance of Australian nurses : an electroencephalographic and psychometric assessment

University of Technology Sydney. Faculty of Science.Stress and anxiety both have demonstrable impact, causing neuronal damage and death (Sapolsky, 1996, Conrad, 2006), functional connectivity changes (Bishop, 2009, Andreescu et al., 2014), and various cognitive impairments (de Quervain et al., 2000, Savage et al., 2000, Wetzel et al., 2006, Henderson et al., 2012, Nieuwenhuys et al., 2015). However, despite demonstrated quality of care reductions (Sveinsdóttir et al., 2006, Berland et al., 2008) and calls for further research (LeBlanc, 2009, Lees and Lal, 2017), a limited amount of research investigating the impact of stress and anxiety on the cognitive performance of health professionals has been conducted (LeBlanc, 2009). Therefore, the aim of the present study was to examine the relationships between stress, anxiety and cognitive performance in health professionals via comprehensive psychometric and electroencephalography (EEG) assessment; as well as assess the predictive capability of EEG in measuring cognitive performance. Presently, this doctoral research reports on results obtained by analysing data from 118 nurses and 144 non-health professionals. The experimental protocol commenced by capturing participant demographic data, such as, blood pressure, heart rate, as well as hip and waist measurements, followed by the completion of pre-study questionnaires including the Lifestyle Appraisal questionnaire (Craig et al., 1996), the Depression, Anxiety, Stress scale (Lovibond and Lovibond, 1995b), and the Fatigue State Question (Lal and Craig, 2002). Following this, a two lead bipolar or 32 lead monopolar EEG was captured during a resting baseline and a Stroop test based active phase. After the electroencephalogram recording, psychometric cognitive performance was assessed by the Mini-Mental State Examination (Folstein et al., 1975) and the Cognistat (Mueller et al., 2007). Participants then completed the revised Ways of Coping Checklist (Vitaliano et al., 1985), and the Fatigue State Question, again for the latter. Nurse participants also completed parts of the Standard Shiftwork Index (Barton et al., 1995). Lastly, participant’s blood pressure was again recorded and the experiment concluded. The results indicate that both non-health professionals and nurses experience stress and anxiety. In both groups, a stress level within the normal range was significantly associated (p < 0.05) with increased memory performance and delta activity, while theta and beta activity increases were similarly implicated for the nurse group only. However, with an increase in stress levels, stress was associated with increased judgement performance and fronto-temporal and parietal gamma activity, as well as reduced fronto-temporal delta activity in non-health professionals. Additionally, impaired memory performance as well as fronto-central delta, fronto-temporal and parietal gamma, and fronto-central and temporal beta activity increases were associated with this increased stress in nurses. With respect to anxiety, it was associated with increased lifestyle risk factors, impaired global, attention, and memory domain performance, as well as delta, alpha and gamma activity changes in non-health professionals. Comparatively, in nurses anxiety was associated with improved Stroop test performance, global cognitive performance and delta and gamma activity, as well as impaired memory performance. Lastly, it was found that global cognitive performance could be predicted by a combination of fast wave EEG activity variables (R² ≥ 0.440; p ≤ 0.013). Similarly, unique combinations of EEG variables from the 5 investigated frequency bands predicted, in varying degrees, attention (R² ≥ 0.204; p ≤ 0.014), memory (R² ≥ 0.443, p ≤ 0.010) and judgement (R² ≥ 0.407; p ≤ 0.001) domain performance. Collectively, these findings provide an insight into the cognitive impact of stress and anxiety, and determine a unique impact profile of stress and anxiety for both non-health professionals and nurses. Additionally, they demonstrate the multifaceted nature of the relationship between stress, anxiety and cognitive performance, where both improvements and impairments are observed. Further understanding the impact of stress and anxiety on cognitive performance may enable the development and implementation of management and intervention strategies to preserve the cognitive health of health professionals, and in turn, ensure quality of patient care and reduce adverse medical event incidence. Further, it may be possible to use EEG activity to predict early cognitive impairment, which has strong implications for developing diagnostic measures for cognitive impaired states such as dementia and Alzheimer’s disease

A systematic review of the current evidence regarding interventions for anxiety, PTSD, sleepiness and fatigue in the law enforcement workplace

Law enforcement is inherently stressful, and police officers are particularly vulnerable to mental and physical disorders. As such, researchers are currently assessing intervention strategies that may combat or manage these psychological, physical and mental issues. To review most recent information regarding anxiety, PTSD, and sleepiness and fatigue and identify the interventions and treatments proposed to overcome work related stressors and associated mental illnesses inflicting law enforcement officers. The EMBASE, OVID MEDLINE and PsycINFO databases were canvassed for articles investigating anxiety, post-traumatic stress disorder, sleepiness, and fatigue. Initial article selections were made based on title, whilst final inclusion was informed by a full critical appraisal with respect to the primary and secondary effects. The systematic search returned 363 records, of which 183 were unique. Following screening, 43 records were included in the final review. The included literature assessed the efficacy of several interventions, and provided a number of recommendations regarding interventions, and policy. Moreover, literature indicates that police officers benefit from interventions targeting work-related stress and potential psychological disorders, if these interventions are continuous. Furthermore, larger controlled studies are required to further elucidate the benefits of psychosocial intervention in law enforcement

A Search for Dark Higgs Bosons

Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb-1 of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the Standard Model-dark sector mixing angle and the dark sector coupling constant.Comment: 7 pages, 5 postscript figures, published version with improved plots for b/w printin

B0 meson decays to rho0 K*0, f0 K*0, and rho-K*+, including higher K* resonances

We present branching fraction measurements for the decays B0 -> rho0 K*0, B0 -> f0 K*0, and B0 -> rho- K*+, where K* is an S-wave (K pi)_0* or a K*(892) meson; we also measure B0 -> f0 K_2*(1430)^0. For the K*(892) channels, we report measurements of longitudinal polarization fractions (for rho final states) and direct CP-violation asymmetries. These results are obtained from a sample of (471.0 +/- 2.8) x 10^6 BBbar pairs collected with the BaBar detector at the PEP-II asymmetric-energy e+ e- collider at the SLAC National Accelerator Laboratory. We observe rho0 K*(892)^0, rho0 (K pi)_0^{*0}, f0 K*(892)^0, and rho- K*(892)+ with greater than 5 sigma significance, including systematics. We report first evidence for f0 (K pi)_0^{*0} and f0 K_2*(1430)^0, and place an upper limit on rho- (K pi)_0^{*+}. Our results in the K*(892) channels are consistent with no direct CP-violation.Comment: 17 pages, 6 postscript figures, submitted to Phys. Rev.

Electrophysiological Brain-Cardiac Coupling in Train Drivers during Monotonous Driving

Electrophysiological research has previously investigated monotony and the cardiac health of drivers independently; however, few studies have explored the association between the two. As such the present study aimed to examine the impact of monotonous train driving (indicated by electroencephalogram (EEG) activity) on an individual’s cardiac health as measured by heart rate variability (HRV). Sixty-three train drivers participated in the present study, and were required to complete a monotonous train driver simulator task. During this task, a 32 lead EEG and a three-lead electrocardiogram were recorded from each participant. In the present analysis, the low (LF) and high frequency (HF) HRV parameters were associated with delta (p &lt; 0.05), beta (p = 0.03) and gamma (p &lt; 0.001) frequency EEG variables. Further, total HRV was associated with gamma activity, while sympathovagal balance (i.e., LF:HF ratio) was best associated fronto-temporal delta activity (p = 0.02). HRV and EEG parameters appear to be coupled, with the parameters of the delta and gamma EEG frequency bands potentially being the most important to this coupling. These relationships provide insight into the impact of a monotonous task on the cardiac health of train drivers, and may also be indicative of strategies employed to combat fatigue or engage with the driving task