An analysis of regulatory mechanisms during sustained task execution in cognitive, motor and sensory tasks
- Authors: Tau, Sethunya Harriet Hlobisa
- Date: 2013 , 2013-10-11
- Subjects: Work -- Physiological aspects , Work -- Psychological aspects , Fatigue , Attention , Mental fatigue , Human information processing , Decision making , Labor productivity , Employees -- Workload , Performance
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5140 , http://hdl.handle.net/10962/d1006806 , Work -- Physiological aspects , Work -- Psychological aspects , Fatigue , Attention , Mental fatigue , Human information processing , Decision making , Labor productivity , Employees -- Workload , Performance
- Description: Fatigue is a state that, although researched for many years, is still not completely understood. Alongside this lack of a general understanding of fatigue is a lack of knowledge on the processes involved in the regulation of fatigue. The existing theories relating to regulation are focussed on mental effort regulation, suggesting that performance outcomes are co-ordinated by effort regulation that functions by making alterations to physiological processes and strategic adjustments at a cognitive level in response to cognitive demands and goals. Since fatigue is a multi-dimensional construct with psychological, physiological, and behavioural effects that respond to endogenous and exogenous variables, it follows then that fatigue assessment techniques ought to include multi-dimensional measures to acquire a holistic depiction of the fatigue symptom. This study aimed to assess whether or not a mechanism that regulated fatigue during sustained task execution could be identified and whether this mechanism resulted in regulation patterns that were distinct to a specific task. An additional aim of the study was on assessing whether the manner in which performance, psychophysical and subjective variables were modified over time followed a similar regulation pattern. The research design was aimed at inducing task-related fatigue twice on two different occasions in the same participants and evaluating the resultant changes in fatigue manifestation. This was done to assess the ability of participants to cope with fatigue as a result of previous experience. The research protocol included three tasks executed for an hour aimed at targeting and taxing the sensory, cognitive, motor resources, each task performed twice. 60 participants were recruited to participate in the current study, with 20 participants – 10 males and 10 females – randomly assigned to each of the three tasks. The cognitive resource task consisted of a memory recall task relying on working memory intended to evaluate the extent of reductions in memory and attention. The sensory resource task consisted of a reading task measuring visual scanning and perception designed to evaluate the extent of reduced vigilance. The motor resource task consisted of a modified Fitts’ stimulus response task targeted at monitoring the extent of movement timing disruption. Performance measures comprised of: response delay and the number of correctly identified digits during the cognitive resource task, the amount of correctly identified errors and reading speed during the sensory resource task, response time during the motor resource task, and responses to simple auditory reaction time tests (RTT) initiated at intervals during the task and then again at the end of each task. Physiological measures included ear temperature, eye blink frequency and duration, heart rate (HR), and heart rate variability (HRV). Subjective measures included the use of the Ratings of Perceived Exertion Category Ratio 10 scale (RPE CR 10) to measure cognitive exertion and the NASA-Task Load Index (NASA-TLX) to index mental workload. Eye blink frequency and duration, HR and HRV were sensitive to the type of task executed, showing differing response patterns both over the different tasks and over the two test sessions. The subjective measures indicated increasing RPE ratings over time in all tasks while the NASA-TLX indicated that each task elicited different workloads. Differing task performance responses were measured between the 1st test session and the 2nd test session during all tasks; while performance was found to improve during the 2nd test session for the motor and sensory tasks, it declined during the cognitive task. The findings of this research indicate that there was a regulatory mechanism for fatigue that altered the manner in which performance, psychophysical and subjective variables were modified over time, initiating a unique fatigue regulation pattern for each variable and each task. This regulation mechanism is understood to be a proactive and protective mechanism that functions through reducing a person’s ability to be vigilant, attentive, to exercise discernment, and to direct their level of responsiveness, essentially impacting how the body adapts to and copes with fatigue. The noted overall findings have industry implications; industries should consider accounting for the effects of this regulatory mechanism in their fatigue management interventions, specifically when designing job rotation and work/rest schedules because each cognitive task, having elicited a unique fatigue regulation pattern, ought to also have a different management program. , Microsoft� Office Word 2007 , Adobe Acrobat 9.54 Paper Capture Plug-in
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- Date Issued: 2013
Job satisfaction as a moderator of the relationship between work-family conflict and stress among female civil service managers in the Department of Education in the King William’s Town District
- Authors: Binqela, Thembisa
- Date: 2013
- Subjects: Job satisfaction -- South Africa -- Eastern Cape , Job stress -- South Africa -- Eastern Cape , Work -- Psychological aspects , Role conflict , Women employees -- South Africa -- Eastern Cape , Women executives -- South Africa -- Eastern Cape , Working mothers -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MCom (Industrial Psychology)
- Identifier: vital:11553 , http://hdl.handle.net/10353/d1007092 , Job satisfaction -- South Africa -- Eastern Cape , Job stress -- South Africa -- Eastern Cape , Work -- Psychological aspects , Role conflict , Women employees -- South Africa -- Eastern Cape , Women executives -- South Africa -- Eastern Cape , Working mothers -- South Africa -- Eastern Cape
- Description: The research at hand focuses on job satisfaction as a moderator of the relationship between work-family conflict and stress among female civil service managers in the Department of Education in the King William’s Town District. Samples of 100 employees were used in the study. The data was collected by means of a questionnaire which consisted of the following sections: (i) a biographical and occupational data questionnaire,(ii) Eum, Lee, and Paek’s (2007) Effort-Reward Imbalance questionnaire, (iii) Bedenia, Burke, and Moffat’s (1998) Short-form Work-family Conflict questionnaire, and (iv) Halpern’s (1966) Job Satisfaction questionnaire. The data were analyzed by means of Pearson’s Correlation Technique, Multiple Regression Analysis, and Analysis of Variance. The results showed that job satisfaction does not moderate the relationship between work-family conflict and occupational stress. The study also found a significant positive correlation between work-family conflict and occupational stress and between work-family conflict and job satisfaction. It also showed that both work-family conflict and job satisfaction respectively accounted for a significant proportion of variance in occupational stress. The thesis ends with several recommendations for future research and for future professional or managerial practice.
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- Date Issued: 2013
Relationships between psychological capital, work engagement and organisational citizenship behaviour in South African automative dealerships
- Authors: Harris, Chantel
- Date: 2012
- Subjects: Work -- Psychological aspects , Employee motivation , Job satisfaction -- South Africa , Organizational behavior , Automobile industry and trade
- Language: English
- Type: Thesis , Doctoral , DCom
- Identifier: vital:9395 , http://hdl.handle.net/10948/d1008059 , Work -- Psychological aspects , Employee motivation , Job satisfaction -- South Africa , Organizational behavior , Automobile industry and trade
- Description: Psychological capital (PsyCap), work engagement (WE) and organisational citizenship behaviour (OCB) are all positive constructs which research has indicated will have a positive impact on the bottom line. In light of Positive Organisational Behaviour, this has become increasingly important, particularly in the service industry where good service leads to satisfied customers and ultimately repeat purchases. This research took on the form of a cross- sectional design, using a composite questionnaire to measure PsyCap, WE and OCB. This was a self-report electronic questionnaire which was distributed via email to customer service representatives (N=276) from a national automotive company with dealerships in Gauteng and the Western Cape. The measurement models were revalidated for the South African sample of customer service representatives through conducting Exploratory Factor Analysis. PsyCap remained a four-factor structure, however lost items in the elimination process. Both the UWES and OCB instruments lost items and became two-factor structures. This makes the notion that these instruments are portable to the South African situation questionable. To confirm these structures, item parcelling was utilised and Confirmatory Factor Analysis was conducted. The results indicated that the new measurement models were better suited to the South African sample. Demographic groups had significant differences in the means for PsyCap, WE and OCB. Further to this, relationships between the constructs were tested through multiple regression and structural equation modeling. The most significant relationship was found between PsyCap and work engagement. Finally, PsyCap (barring optimism) and WE were found to load onto a single factor when testing for factorial independence, while OCB came out as a separate factor.
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- Date Issued: 2012
Strategies for managing work related stress
- Authors: Müller, Elsie Franscina
- Date: 2007
- Subjects: Stress management , Job stress , Work -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8577 , http://hdl.handle.net/10948/742 , Stress management , Job stress , Work -- Psychological aspects
- Description: The objective of this study was to identify the strategies (primary, secondary and tertiary) that can be employed to manage work related stress. A questionnaire, was designed based on the strategies found in a literature study on the topic and used to gather inputs from academic head of department and lecturers. The questionnaire was delivered by hand to 18 potential respondents. All 16 questionnaires returned could be used. These were processed and analysed using Microsoft Excel spreadsheets. In general support was found for primary stress management strategies pertaining to work schedule, work load and work pace, job content, career development, the home-work relationship and work environment. Lifestyle management in terms of physical activities and a healthy diet were regarded as the preferred secondary stress management strategies. The strategies related to lifestyle management which were identified from the literature study were physical activities, healthy diet, relaxation techniques such as meditation and yoga. Support was found for tertiary stress management strategies but most of the respondents were not sure if their organisation offered any wellness, employee assistance or stress management programmes. Wellness programmes were indicated as a strategy that will have the most impact on reducing work related stress and employee assistance programmes (EAPs) ranked there after. Overall respondents indicated that they did not perceive their work as very stressful.
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- Date Issued: 2007
The contribution of psychogenic factors limiting prolonged work performed at different relative intensities
- Authors: Rorke, Stafford Conroy
- Date: 1986
- Subjects: Physical fitness -- Measurement , Physical fitness -- Psychological aspects , Work measurement , Work -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5103 , http://hdl.handle.net/10962/d1004772 , Physical fitness -- Measurement , Physical fitness -- Psychological aspects , Work measurement , Work -- Psychological aspects
- Description: This study investigated the physiological and psychological limitations to prolonged work performed at different relative intensities, through the use of an eclectic integrative methodology. Ten young male caucasian subjects (mean V0₂ max. 60,0 ml.kg⁻¹.min⁻¹ ± 7,9) were randomly exposed to treadmill runs at each of four relative intensities, namely 55%, 65%, 75% and 85% of V0₂ maximum, with the instruction to run to the point of subjective discomfort at which they were no longer willing to continue. Physiological measures of oxygen consumption (V0₂), heart rate (HR), respiratory exchange ratio (R) , minute ventilation volume (Vi), breathing frequency (Vf), tidal volume (Vt) and psychological measures of Ratings of Perceived Exertion (RPE), Perceived Thermal Comfo·rt (PTC), Perceived Pain and Perceived Fatigue were recorded throughout the protocol. The relative intensity was held constant by slight decreases in treadmill speed as subjects fatigued, and through feedback from an on-line oxygen consumption computer-aided data acquisition system. Significant increases in both physiological and psychological measures occurred with increases in relative intensity (p<0,05). HR and Vf increased overtime (p<0,05) whilst Rand Vt decreased over time (p < 0,05) . All psychological ratings increased in intensity over time (p < 0,05). Mean endurance times to exhaustion were 243 minutes ± 70 at 55% relative intensity, 159 minutes ±37 at 65%, 96 minutes ±25 at 75 % and 23 minutes +- 8 at 85%, being within the range reported by earlier researchers . A regression equation for prediction of endurance time given a known relative intensity was developed for this sample: % V0₂ max. = 117,8 + (-10,6 x LN (time)) (where r = -0,91) Convergence rankings indicate the greater contribution of local factors in the overall gestalt of perceived exertion, pain and fatigue, with biomechanical limitations to prolonged work (running) strongly implicated . High inter correlations between psychological rating scales suggest the use of the scale considered most applicable to the task at hand and the psychological response measure required. A coefficient of multiple correlation of 0,94 established the close interrelationship amongst the physiological and psychological parameters measured. Pre- and post-test Fatigue Cluster Analysis questionnaires indicated that the most important clusters contributing toward the sensation of fatigue and subsequent decision to cease activity were Task Aversion and General Fatigue (r = 0,96), followed by Leg Fatigue and Thirst. Motivation, the task at hand and an attainable goal appear to be important considerations in prolonged work performance. Relative intensity appears a valid tool for use in prolonged work studies due to its high predictive capacity for endurance performance times (r=-0,91). It is concluded that workloads considerably below 55% of maximal aerobic capacity are indicated as acceptable workloads for an 8 hour working day.
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- Date Issued: 1986