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Slips, trips, and falls are the costliest source of disabling injuries in the workplace, costing $18.6 billion annually. The purpose of this study was to investigate the effects of mental fatigue on gait variables associated with the risk of slipping and tripping. The study also investigated the efficacy of a 10-minute rest break in mitigating the effect of mental fatigue on those variables. Twenty healthy young adults (10 males and 10 females) participated and completed two experimental sessions. The order of sessions was counter-balanced for each participant. During the mental fatigue session, participants completed a computerized mentally fatiguing task for 90 minutes and performed a set of gait trials every 15 minutes throughout the task. During the control session, participants watched an emotionally neutral documentary in place of the mentally fatiguing task. After 90 minutes of the task or documentary, participants took a 10- minute break and then completed one last set of gait trials. Risk of slipping was inferred from the required coefficient of friction, heel contact velocity, and heel contact angle. Risk of tripping was inferred from minimum toe clearance and obstacle clearance. The results showed no increase in slip or trip risk. Rest breaks appeared to decrease levels of self-reported mental fatigue. However, they did not appear to have any mitigating effect on any of the gait variables that were measured. / Master of Science / Slips, trips, and falls are the costliest source of disabling injuries in the workplace, costing $18.6 billion annually. The purpose of this study was to measure the effect of mental fatigue on the risk of falling. In this study, twenty healthy young adults (10 males and 10 females) completed two sessions. In the first session, the participants completed multiple walking sessions while performing a mentally fatiguing task. In the second session, the participants identical walking sessions, with the exception that instead of performing a mentally fatiguing task, they were watching a documentary. The study also aimed to study whether a 10-minute rest break could reduce the effect of mental fatigue on the participants' risk of falling. The results showed that mental fatigue had no effect on slip or trip risk. The rest break was successful at decreasing the self-reported mental fatigue rating but had no effect on the risk of slipping or tripping.

Approved for public release; distribution is unlimited / Fatigue due to sleep deprivation is a major factor in both mental and physical performance. Failure of Recruits to receive the proper quality and quantity of sleep can be detrimental to a Recruit’s safety and can diminish the amount of information learned during training. During the 1980s, the sleep regimen was decreased to 6 hours of sleep per night. In 2002, a decision was made to give U.S. Navy Recruits an additional two hours of sleep per night. This latest modification was selected to coincide with the acknowledged adolescent/young adult circadian rhythms. The purpose of this study was to determine the impact of the new eight-hour sleep regimen using standardized test scores as a performance measure. One year of data with the eight-hour sleep regimen is compared to two separate years when only six hours of sleep was allowed. There is a significant difference, F(2, 33) = 29.82, p < .0001, between the test scores of Recruits receiving 6-hours of sleep and 8-hours of sleep. On average test scores rose by 11 percent with the additional sleep. The odds of observing such a difference by chance is less than one in ten million. / Lieutenant Commander, United States Navy

The purpose of the study was to investigate adults who have excessive load or demands ("Overloaded Adults") and their readiness level for learning ("Readiness"). The study was intended to discover the relationship, if any, between Overloaded Adults' load and their Readiness, the reasons Overloaded Adults do not participate in particular educational activities, the percentages of Overloaded Adults in a range from "able and willing" to "neither able nor willing" to participate in various educational activities, the power sources Overloaded Adults identify as present or not present, and how Overloaded Adults' demographic characteristics relate to their load and Readiness.The sample in the study consisted of 60 Overloaded Adults. The researcher used a convenience sampling of available passersby walking on downtown sidewalks in four Indiana cities who were willing to stop and complete the written survey, which consisted of two parts: the Type E Stress Inventory developed by Harriet B. Braiker and a questionnaire developed by the researcher. The researcher also conducted 21 tape-recorded telephone interviews. The researcher analyzed the data using the Pearson correlation coefficient statistic and a scatter plot, tallies and percentages, observations, and interview responses incorporated into a profile and description of general themes.The researcher discovered that the majority of adults (77%) walking on downtown sidewalks on Saturdays were Overloaded Adults. Further, the researcher found, unlike McClusky's theory of margin, that there was likely no relationship between Overloaded Adults' load and Readiness and that Overloaded Adults with a surplus of power over load were not necessarily more likely to learn than Overloaded Adults with a surplus of load over power. The researcher also found 1) at least 30 inhibiting conditions or situations that shaped Overloaded Adults' perceptions of their readiness to learn, 2) Overloaded Adults were very willing and somewhat able to participate in various educational activities, 3) Overloaded Adults had numerous available sources of power, and 4) Overloaded Adults with particular demographic characteristics were at high risk for not being ready to learn. Based on these and other findings in the study, the researcher developed a Model for Understanding Overloaded Adults' Readiness Level for Learning. / Department of Educational Leadership

Thesis (M.S. in Operations Research)--Naval Postgraduate School, Sept. 2004. / Thesis advisor(s): Nita Lewis Miller. Includes bibliographical references (p. 87-90). Also available online.

Thesis (M. S.)--Psychology, Georgia Institute of Technology, 2010. / Committee Chair: Dr. Phillip L. Ackerman; Committee Member: Dr. Paul Corballis; Committee Member: Dr. Ruth Kanfer. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Mental fatigue impairs performance of physically-demanding tasks and increases rating of perceived exertion (RPE) while performing. However, there may be ways of overcoming such performance decrements. One possible method includes the use of attentionally focused instructions. Motor learning research has shown that externally focused instructions can lead to improved performance in comparison to internally focused instructions. The purpose of the present study was to investigate the moderating effect of attentional focus on the mental fatigue – endurance performance relationship as well as the mental fatigue – perceived exertion relationship. Undergraduate students (N = 78) completed two wall sit tasks to volitional failure, one before and one after the completion of a cognitive task. Half the participants were randomly assigned to complete a high cognitive demand task to induce mental fatigue (incongruent Stroop; HMF), while the other half performed a low cognitive demand task (documentary viewing; LMF) before the second wall sit. Immediately prior to the second wall sit, half the participants in each cognitive task group also received instructions to focus their attention either internally (INT) or externally (EXT) during the second wall sit. The main effect of mental fatigue (p < .001, d = .873) during the cognitive task and the main effect of attentional focus (p < .001, d = .883) during the wall sit task were significant, indicating effective manipulations. Results found no moderating effect of attentional focus on wall sit performance (p >.500) or RPE (p = .724). However, between-group analyses were conducted to probe the differences in performance between each group. Results indicated the HMF/INT group performed significantly worse than the LMF/EXT (p = .032) and trended towards performing worse than the HMF/EXT and LMF/INT groups (ps < .090). Significant differences in RPE were also seen between trials for the HMF/INT group (p = .009, d = .592) alone, suggesting detrimental effects of both mental fatigue and internal focus combined. Overall, the data indicate a potential moderating effect of internal attentional focus that may exacerbate the detrimental effects of mental fatigue on performance and RPE. / Thesis / Master of Science (MSc)

Thesis (M.S. in Operations Research)--Naval Postgraduate School, September 2009. / "September 2009." Thesis advisor: Nita Lewis Miller. Performed by Naval Postgraduate School, Monterey, CA. Includes bibliographical references (p. 59-60). Also available online from the Naval Postgraduate School (NPS), Dudley Knox Library and the DTIC Online Web sites.

Previous research has examined a variety of behavioural effects, thought to stem from mental exhaustion, following the prior use of inhibitory control. Here we attempt to examine whether such effects are apparent in unconscious behaviours. Chapter 1 demonstrates no effect of prior use of inhibitory control on subsequent susceptibility to subliminal priming of neutral (Experiment 1) and reward (Experiment 2) terms. Chapter 2 explores whether the prior use of inhibitory control influences the degree of susceptibility to an alternative source of influence, hypnotic induction, and provides the novel finding that inhibitory impairment does not affect hypnotic response. Chapter 3 utilises behavioural and fMRI imaging data to examine changes in a conscious facet of human experience often moderated by unconscious influences: emotion regulation. The results support a period of increased mood lability following a challenging inhibitory control task. However, we were unable to provide evidence of any underlying change in cortical activation and connectivity. Finally, Chapter 4 investigates whether this heightened mood lability following prior inhibitory control would also be mirrored in ratings of emotion attributed to positive and negatively valenced images (Experiment 1) and additionally, whether a mindfulness induction, previously documented to improve emotion regulation, would reduce individuals' perception of the degree of valence attributed to the same images (Experiment 2). Contrary to predictions, we report substantial evidence for no effect of prior inhibitory control or a brief mindfulness manipulation on subsequent ratings of emotionally valenced stimuli. Taken together the research indicates that mental exhaustion arising from the use of self-control appears to have no effect on susceptibility to unconscious priming, hypnotic suggestions, and no effect on the perception of emotionally valenced images. However, prior use of inhibitory control does appear to affect the degree of emotional lability experienced following music.

Inaug.-diss.--Heidelberg. / "Sonderabdruck aus Kraepelin, Psychologische arbeiten. I. bd. 2. heft."