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The Effects of Early Social Deprivation on Appetitive Motivation in RatsLomanowska, Anna 10 January 2012 (has links)
Social interactions in early life influence the organization of neural and behavioural systems of developing mammalian young. Deprivation of social interactions with the primary caregiver and other immediate conspecifics (early social deprivation) has lasting consequences on behavioural functioning in later life. The purpose of this thesis was to investigate how early social deprivation affects the motivational aspects of behaviour in the context of appetitive stimuli. Rats were reared in complete isolation from the mother and litter using the method of artificial rearing (AR). Control rats were maternally reared (MR). In adulthood, rats were tested in a series of behavioural paradigms designed to assess the motivational impact of primary food reward and reward-related cues on food-seeking behaviour. AR increased the behavioural responsiveness of rats to the motivational impact of reward-related cues, but not to primary rewards themselves. Specifically, there were no significant effects of AR on food consumption or goal-directed instrumental responding for food. However, AR enhanced instrumental responding triggered by a previously conditioned reward cue. AR also increased the expression of approach behaviour towards a localizable conditioned reward cue and instrumental responding when the same cue was used as a reinforcer. An assessment of the mediating factors during development revealed that the lack of tactile stimulation normally received from the mother, but not sustained exposure to the stress hormone corticosterone, contributed to the long-term effects of AR. These findings represent a potential link between early-life social adversity and vulnerability to the development of problems with behavioural inhibition and attention in the presence of appetitive environmental cues.
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Subtle Effects of Sleepiness on Electrocortical Indices of Attentional Resources and Performance MonitoringMurphy, Timothy Ian 02 February 2007 (has links)
In this dissertation, the effect of mild sleep deprivation on attentional allocation and performance monitoring was investigated using a variety of event-related potential (ERP) paradigms with ecologically realistic periods of sleep deprivation. Seventeen female young adults completed several tasks under alert and sleepy conditions, after 3 and 20 hours of wakefulness, respectively. Objective behavioural measures of response times and error rates indicated virtually no decrements that could be attributed exclusively to sleepiness; however, there were consistent alterations in the ERPs indicative of subtly reduced attentional resources and performance monitoring.
The first study (Chapter 2) examined the effect of distraction on the P300, an ERP component related to attention and stimulus processing. Participants performed an auditory oddball task with and without a secondary visual working memory task. Response times (RTs) and P300 amplitudes were affected by the addition of the secondary working memory task. However, an interaction showed that the P300 latency was significantly increased by the secondary task only in the sleepy condition, indicating that processing speed is impaired by a secondary task only when the participant is sleepy. The next study (Chapter 3) used a Go/NoGo contingent negative variation (CNV) task. The CNV is reflective of sustained attention, and is known to be associated with frontal lobe functioning. This task was performed twice, with and without a financial incentive for fast responses, to assess the effect of motivation. The P300 amplitude to the first stimulus and CNV prior to the second were clearly larger to Go stimuli for both levels of alertness when the participant was motivated by the financial incentive. However, with no incentive in the sleepy condition, there was reduced differentiation of the two types of stimuli, indicating a reduced ability to discriminate between important and less important information.
In chapters 4 and 5, performance monitoring was examined using two tasks, the Eriksen Flanker task and the Anti-Saccade task, producing an ERP related to errors with two basic components: the error-negativity (Ne/ERN) and error-positivity (Pe), thought to be related to error recognition and error evaluation, respectively. In both data sets, the amplitude of the Ne/ERN was not significantly reduced by sleep deprivation, but the amplitude of the Pe was. In addition, smaller anti-saccade errors produced reduced Ne/ERN amplitudes compared to larger anti-saccade errors. Another marker of performance monitoring is post-error slowing, which was present in the flanker task only during the alert condition. These results indicate that error detection or recognition (Ne/ERN) appears to be relatively preserved during sleep deprivation, but further error evaluation (Pe) and compensation (post-error slowing) are impaired.
Taken together, the findings demonstrate that even mild sleep deprivation has a subtle but reliable effect on electrocortical activity associated with attention and performance monitoring despite an absence of behavioural changes, indicating deleterious effects before behavioural changes are observed. Therefore, relying on behavioural tests to determine at what point an individual becomes unsafe to operate machinery or perform various tasks may be misleading.
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Subtle Effects of Sleepiness on Electrocortical Indices of Attentional Resources and Performance MonitoringMurphy, Timothy Ian 02 February 2007 (has links)
In this dissertation, the effect of mild sleep deprivation on attentional allocation and performance monitoring was investigated using a variety of event-related potential (ERP) paradigms with ecologically realistic periods of sleep deprivation. Seventeen female young adults completed several tasks under alert and sleepy conditions, after 3 and 20 hours of wakefulness, respectively. Objective behavioural measures of response times and error rates indicated virtually no decrements that could be attributed exclusively to sleepiness; however, there were consistent alterations in the ERPs indicative of subtly reduced attentional resources and performance monitoring.
The first study (Chapter 2) examined the effect of distraction on the P300, an ERP component related to attention and stimulus processing. Participants performed an auditory oddball task with and without a secondary visual working memory task. Response times (RTs) and P300 amplitudes were affected by the addition of the secondary working memory task. However, an interaction showed that the P300 latency was significantly increased by the secondary task only in the sleepy condition, indicating that processing speed is impaired by a secondary task only when the participant is sleepy. The next study (Chapter 3) used a Go/NoGo contingent negative variation (CNV) task. The CNV is reflective of sustained attention, and is known to be associated with frontal lobe functioning. This task was performed twice, with and without a financial incentive for fast responses, to assess the effect of motivation. The P300 amplitude to the first stimulus and CNV prior to the second were clearly larger to Go stimuli for both levels of alertness when the participant was motivated by the financial incentive. However, with no incentive in the sleepy condition, there was reduced differentiation of the two types of stimuli, indicating a reduced ability to discriminate between important and less important information.
In chapters 4 and 5, performance monitoring was examined using two tasks, the Eriksen Flanker task and the Anti-Saccade task, producing an ERP related to errors with two basic components: the error-negativity (Ne/ERN) and error-positivity (Pe), thought to be related to error recognition and error evaluation, respectively. In both data sets, the amplitude of the Ne/ERN was not significantly reduced by sleep deprivation, but the amplitude of the Pe was. In addition, smaller anti-saccade errors produced reduced Ne/ERN amplitudes compared to larger anti-saccade errors. Another marker of performance monitoring is post-error slowing, which was present in the flanker task only during the alert condition. These results indicate that error detection or recognition (Ne/ERN) appears to be relatively preserved during sleep deprivation, but further error evaluation (Pe) and compensation (post-error slowing) are impaired.
Taken together, the findings demonstrate that even mild sleep deprivation has a subtle but reliable effect on electrocortical activity associated with attention and performance monitoring despite an absence of behavioural changes, indicating deleterious effects before behavioural changes are observed. Therefore, relying on behavioural tests to determine at what point an individual becomes unsafe to operate machinery or perform various tasks may be misleading.
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Collective Political Violence in the North Caucasus: Chechen Conflict and Insurgency AnalysisEdwards, Michael January 2012 (has links)
This Bachelor thesis is a study of collective political violence in the context of the Chechen conflict which continues to this present day. The information gathered and analysed as well as the frameworks used in the analysis are taken from numerous academic texts written on the subjects of Chechnya, Terrorism and theories on conflict and conflict resolution. The Chechen conflict is a decade long intra-state conflict which has its roots in a separatist movement for secession following the breakup of the Soviet Union. The dynamics of the conflict has evolved throughout the years, maintaining many of its fundamental elements whilst at the same time transforming as new actors and dimensions emerge. Following an abductive approach, the analytical frameworks of John Burton and Ted Gurr as well as a theoretical perspective derived from Bruce Hoffman’s understanding of terrorism, have been used to recontextualise to information gathered through the selected academic texts relevant to the conflict. The aim of this recontextualisation is to attempt to identify hidden mechanisms that could be responsible for the occurrence of collective political violence in the context of Chechnya. Numerous deprivations of the Chechen people’s basic human needs can potentially lead to frustration being perceived through a sense of shared group interest identity. Elites can then use this identity to mobilize the discontented masses in order to obtain political power for themselves whilst achieving the goals of the group they claim to represent. Russia’s Counterterrorism strategy does not seek to address these grievances and therefore violence is likely to continue to occur.
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Behavioural effects of food deprivation on red junglefowl (Gallus gallus) and White Leghorn layersLind, Jenny January 2007 (has links)
<p>The aim of this study was to examine how food deprivation effects food-related and other behavioural systems of red junglefowl (Gallus gallus) and the domesticated White Leghorn layers. If an animal is denied to perform their natural behaviours, like eating, sleeping or preening, the motivation for the behaviour can increase. Behavioural systems may interact and motivation to perform behaviours may be influenced. After being deprived of a certain need the reaction can become exaggerated or abnormal. Food deprivation is often used in ethology research to motivate animals. The hypothesis in this study was that the chickens would become affected by the food deprivation and reallocate their behaviours. They would get more stressed and frustrated. Domestication effects and sex differences were explored. The birds were tested in four standardized behavioural tests; food consumption test, general behavioural test, open field test and novel object test. The results showed that they foraged and explored more, had less comfort behaviours, and less perching the longer they had been without food. They did not show a higher degree of frustration, stress or aggressive behaviours. There were domestication effects, where the Leghorns seem to have lost some of their ability to respond adaptively to food shortage. Differences between the sexes were found, where the females foraged more and the males were more stressed. The conclusion was that the birds do not get more stressed when food deprived, but they forage and explore more which is a desirable effect of food deprivation used in ethology research.</p>
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Effects of morphine, d-amphetamine, and food deprivation on temporally organized behaviorKnealing, Todd W. January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains vii, 109 p. : ill. Includes abstract. Includes bibliographical references (p. 101-109).
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Hot flashes in men with prostate cancer: Prevalence, severity, and psychosocial correlatesWinters, Erin 01 June 2006 (has links)
The present study evaluated the prevalence, severity, and psychosocial correlates of hot flashes in men receiving androgen deprivation therapy for prostate cancer. Seventy-two men completed a detailed packet of questionnaires prior to the initiation of treatment and again three-months later. Results indicated that the extent to which hot flashes interfered with patients' daily functioning significantly contributed to changes in depressive symptoms. Changes in fatigue were found to mediate the relationship between hot-flash related interference and depressive symptomatology, suggesting that increases in fatigue were responsible for the concurrent increases in symptoms of depression. The coping strategy of catastrophizing moderated the relationship between hot flash-related interference and cancer-related distress, such that levels of cancer-related distress in men reporting greater use of catastrophizing were dependent upon levels of hot flash-related interference. Men who did not engage in catastrophizing reported uniformly low levels of cancer-related distress regardless of the extent to which hot flashes interfered with daily functioning. Expected relationships between hot flashes and sexual functioning or masculine self-image were not confirmed. These findings provide valuable information regarding the experience of hot flashes in this population. Results indicate that reduction of fatigue may lead to reductions in depressive symptoms, while reducing patients' use of catastrophizing may alleviate cancer-related distress.
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Sleep dependent memory consolidation during a daytime nap in adolescentsMcAteer, Susan Mary Elizabeth. January 2010 (has links)
published_or_final_version / Clinical Psychology / Master / Master of Social Sciences
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Effects of partial sleep deprivation on gastric mucosal damageChau, Fung-ling, Jenny., 周鳳玲. January 2000 (has links)
published_or_final_version / Pharmacology / Master / Master of Philosophy
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The effect of touching on the behavior of elderly personsKiley, Barbara Ann January 1981 (has links)
No description available.
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