Cognitive fatigue refers to the decline in mental efficiency and accompanying feelings of strain and weariness that occur over time-on-task. This study extends previous research on the determinants of cognitive fatigue by evaluating the independent and joint effects of individual differences in extraversion and performance context (individual vs. team) on reports of fatigue. Using a within-subjects counterbalanced design, 92 undergraduate participants performed a three-hour series of problem-solving tasks alone and as part of a four-person team. Results indicated main effects for context, such that all participants report greater fatigue in the solitary performance context compared to the team context. Extraversion was also negatively related to fatigue across time-on-task. However, no extraversion X context interaction was observed. I conclude that task engagement provides a specific source of variance in fatigue-reduction, and suggest that extraverts benefit more from task-related arousal or state positive affect.

Decrements in selective attention are a commonly experienced phenomenon that has practical implications for many industries. Two causes of such deficits are mental fatigue and alcohol intoxication, which impair selective attention by decreasing the efficiency of inhibitory processes. The present research examined the effects of these two factors on the selective attention subtest of the Useful Field of View test in both a baseline and an experimental session. Participants in the mental fatigue condition (n = 14) were tested while performing a divided attention task for two hours to induce mental fatigue. Those in the alcohol condition (n = 10) were tested while achieving a peak blood alcohol content of 0.05%. No differences between the two groups were observed, nor was a significant decline in selective attention observed as a result of either manipulation. The results indicate three possible explanations for this lack of a difference including a floor effect on the selective attention task, a pop-out effect in switching from the divided to the selective attention task, and an increase in attentional effort regulation due to the contrast in difficulty of the divided and selective attention tasks.

Prior caffeine research has examined the effects of caffeine on performance using simple, lower-level cognitive tasks. The present study extended this work to investigate the effects of caffeine on performance and self-report mood measures during execution of a complex cognitive task. In a between-subjects design, 116 participants were administered either caffeinated or non-caffeinated chewing gum. Results showed higher fatigue and negative affect (NA) levels and lower positive affect (PA) and task performance levels in the placebo condition. These findings replicate prior findings on mood effects of caffeine; also, they extend the limited results on performance effects of caffeine by demonstrating moderate support for improved complex cognitive task performance after caffeine intake. Furthermore, these results show the efficacy of gum for caffeine administration in research.

The purpose of this study was to determine if fitness levels of individuals affect cognitive function. This study seeks to show how response inhibition and accuracy are affected following a mentally fatiguing task. Response inhibition refers to the suppression of actions that are inappropriate and that interfere with goal driven behavior. Response inhibition in reference to the continuous performance task (CPT) is measured in false clicks. The tasks for the CPT were completed after either a controlled period of rest or moderate-intensity exercise. Subjects were either Georgia Tech Division I track athletes or students leading a sedentary lifestyle. All subjects participated in two test protocols. Athletic subjects completed the resting protocol first, while sedentary subjects completed the exercise protocol first. Subjects reported to the lab following an overnight fast. They completed an initial set of paper work and signed a consent form, filled out a 24 hour history form and completed a Profile of Moods States (POMS) and Visual Analog Scale (VAS) form. Subjects then took a 20-minute (CPT). The CPT is a neuropsychological test that measures an individual’s sustained and selective attention. The length of the test is 20 minutes in order to induce mental fatigue. The goal of the test is to click in a white box when the letter T is seen. Immediately after subjects filled out a secondary set of paperwork. Once paper work was complete subjects either rested or exercised for 35 minutes. If subject was classified as an athlete, trial 1 was rest, while trial 2 was exercise. If subject was classified as a sedentary student, trial 1 was exercise, and trial 2 was rest. After the subject completed either the cycling or resting portion they repeated the CPT for five minutes. It was hypothesized that that the effects of moderate exercise positively affect the subject’s performance on the CPT. I expect false clicks following the 5 minute CPT to be lower after exercising. I hypothesize that for both groups their accuracy should be higher after moderate cycling and that higher fitness level should decrease the level of mental fatigue experienced throughout the CPT.

Restoration landscape theories propound the observation that landscape mitigates human emotion, mental functioning, and behaviour. Those environments that positively affect these spheres are called "restorative". In recent years, many attempts have been made to quantify restorative landscapes, so that landscape architects and others can replicate them in the manipulated environment. An understanding of how certain combinations of landscape attributes affect humans is important in knowing the ramifications of certain designs. A major finding in recent years is that preferred landscapes—or those high in scenic beauty—are generally more restorative than less-attractive environments. One realm of the environment not dealt with, however, is the sacred landscape. One reason for this is the relative difficulty in narrowing down the term “sacred” to something measurable. The purpose of this thesis is to investigate the nature of sacred landscapes, and then to test sacred landscapes against preferred landscapes to measure their restorative potential. This testing involved subjecting participants to a psychological stressor, and then exposing them to slides rated highly in either sacredness or preference. A control group was also tested, but viewed a blank screen rather than images. Implications of this research impact both researchers and practitioners in the fields of landscape architecture, environmental psychology, public land management, and visual resource management. This study found that sacred landscapes are very restorative, although not quite as restorative as environments that rate highly in scenic beauty. This confirms previous research efforts, and opens the study of restorative environments to other landscape typologies as well.

Numerous aspects of job scheduling in manufacturing systems have been the focus of several studies in the past decades. However, human factors in manufacturing systems such as workers’ mental conditions are still neglected issues and have not received adequate attentions. Job boredom and mental fatigue are both aspects of workers’ mental condition. They affect work performances by increasing sick leave duration and decreasing work productivity. On the other hand, job rotation could be an alternative strategy to cope with such human issues at work. The benefits of job rotation for both employees and firms have been widely recognized in the literature. Although some studies found job rotation as a means to reduce workers' physical work-related traumas, they did not consider the effect of variable mental conditions on workers. Despite the proven importance of boredom and mental fatigue at the workplace, they have not been a combined precise objective of any job rotation problem in current literature. The study of mental conditions proposed in this paper attempts to extend the previous works by addressing new methods and developing a feasible solution to increase manufacturing productivity. A new job scheduling program has been designed specifically which combines a new job rotation model and a job assignment method.

Restoration landscape theories propound the observation that landscape mitigates human emotion, mental functioning, and behaviour. Those environments that positively affect these spheres are called "restorative". In recent years, many attempts have been made to quantify restorative landscapes, so that landscape architects and others can replicate them in the manipulated environment. An understanding of how certain combinations of landscape attributes affect humans is important in knowing the ramifications of certain designs. A major finding in recent years is that preferred landscapes—or those high in scenic beauty—are generally more restorative than less-attractive environments. One realm of the environment not dealt with, however, is the sacred landscape. One reason for this is the relative difficulty in narrowing down the term “sacred” to something measurable. The purpose of this thesis is to investigate the nature of sacred landscapes, and then to test sacred landscapes against preferred landscapes to measure their restorative potential. This testing involved subjecting participants to a psychological stressor, and then exposing them to slides rated highly in either sacredness or preference. A control group was also tested, but viewed a blank screen rather than images. Implications of this research impact both researchers and practitioners in the fields of landscape architecture, environmental psychology, public land management, and visual resource management. This study found that sacred landscapes are very restorative, although not quite as restorative as environments that rate highly in scenic beauty. This confirms previous research efforts, and opens the study of restorative environments to other landscape typologies as well.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2005. / Härtill 4 uppsatser.

Restoration landscape theories propound the observation that landscape mitigates human emotion, mental functioning, and behaviour. Those environments that positively affect these spheres are called "restorative". In recent years, many attempts have been made to quantify restorative landscapes, so that landscape architects and others can replicate them in the manipulated environment. An understanding of how certain combinations of landscape attributes affect humans is important in knowing the ramifications of certain designs. A major finding in recent years is that preferred landscapes—or those high in scenic beauty—are generally more restorative than less-attractive environments. One realm of the environment not dealt with, however, is the sacred landscape. One reason for this is the relative difficulty in narrowing down the term “sacred” to something measurable. The purpose of this thesis is to investigate the nature of sacred landscapes, and then to test sacred landscapes against preferred landscapes to measure their restorative potential. This testing involved subjecting participants to a psychological stressor, and then exposing them to slides rated highly in either sacredness or preference. A control group was also tested, but viewed a blank screen rather than images. Implications of this research impact both researchers and practitioners in the fields of landscape architecture, environmental psychology, public land management, and visual resource management. This study found that sacred landscapes are very restorative, although not quite as restorative as environments that rate highly in scenic beauty. This confirms previous research efforts, and opens the study of restorative environments to other landscape typologies as well. / Applied Science, Faculty of / Architecture and Landscape Architecture (SALA), School of / Graduate