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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Priming Expectancies: Effects on Neurophysiological Indices of Expectancy Violations and Drinking Behavior

Brumback, Tyler 16 February 2010 (has links)
Investigations of the anticipated effects of alcohol indicate that cognitive frameworks are highly correlated with drinking and other variables associated with alcohol use, explaining up to 50% of the variance in drinking outcomes (Goldman, Darkes, & Del Boca, 1999; Goldman, 2002; Goldman et al., 2006; Goldman, Reich, & Darkes, 2006). Furthermore, alcohol expectancies appear to mediate the relationship between a variety of risk factors, such as sensation seeking, and alcohol outcomes (Darkes, Greenbaum, & Goldman, 2004). The current study examined the relationship of these cognitive networks with a physiological index of expectancy violation Participants were presented with statements reflecting a wide range of alcohol outcome effects, which either violated or confirmed the participant’s own set of alcohol expectancies, while the ERPs evoked by these stimuli were recorded. As predicted, the P300 amplitude elicited by negative alcohol expectancy stimuli was positively correlated with the degree of endorsement of positive/arousing expectancies on the self-report measure. That is, the higher the individual’s positive/arousing expectancies, the larger the P300 elicited by stimuli asserting the negative effects of alcohol. There was no significant correlation, however, between P300 amplitude elicited by positive alcohol expectancy stimuli and the degree of endorsement of negative/sedating expectancies on the selfreport measure. In addition, individual differences relating to alcohol expectancies were examined as well. These results were able to identify specific stimuli that violated expectancies for each individual, as well as those that tended to violate expectancies in systematic ways across subjects. These findings provide a way forward for more precise assessment and prediction based on the well developed cognitive model of Alcohol Expectancies. In sum, variations in the amplitude of the P300 were consistent with the model of Alcohol Expectancies. Words imputing negative/sedating effects of alcohol elicited a large P300 in individuals with higher positive alcohol expectancies. By indexing the brain’s electrophysiological response sensitive to expectancy violations, these findings demonstrate concordance between verbal measures of alcohol expectancies, which by their very nature are introspective, and a psychophysiological index of expectancy thought to operate automatically and to be independent of overt responding.
122

The Psychophysiology of Novelty Processing: Do Brain Responses to Deviance Predict Recall, Recognition and Response Time?

Kamp, Siri-Maria 01 January 2013 (has links)
Events that violate expectations are biologically significant and accordingly elicit various physiological responses. We investigated the functional relationship between three of these responses: the P300, the Novelty P3 and the pupil dilation response (PDR), with a particular focus on their co-variance with reaction time and measures of subsequent memory. In a modified Novelty P3 oddball paradigm, participants semantically categorized a sequence of stimuli including (1) words of a frequent category, (2) words of an infrequent category (14% of the trials) and (3) pictures of the frequent category (14% of the trials). The Novelty P3 oddball task was followed by a recall- and a recognition test. Larger amplitudes of the P300, identified by a spatial principal component analysis (PCA), were associated with enhanced subsequent recall as well as faster reaction times during the recognition test, suggesting a close relationship between the cognitive process indexed by the P300 and memory encoding. The PDR was larger for infrequents (which required a response switch) than both frequents and pictures (which did not require a switch). Furthermore, its latency was correlated with reaction time on the same trial and with reaction time on the immediately following trial. There was only weak evidence for a correlation with subsequent memory, suggesting that the cognitive process associated with the PDR might be a direct link in the stimulus-response stream. Larger Novelty P3 amplitudes were associated with both faster reaction times on the same trial and stronger memory traces, suggesting that its amplitude might index resource allocation. These findings suggest that each of the physiological responses carries a distinct functional significance in detecting, processing, or responding to novel events, and we discuss the findings in the light of the prevalent theories of the functional significance of each response.
123

Alcohol expectancy cognitions: Psychophysiological perspective

Fishman, Inna 01 June 2006 (has links)
Considerable evidence indicates that the expectations individuals hold about the effects of alcohol determine, to a degree, the amount of alcohol they drink. However, the bulk of this evidence was acquired using verbally-based measures of expectancy. The present study sought to extend the validation network by utilizing an electrophysiological measure -- the P300 component of the Event Related Potentials (ERPs) -- which is thought to index fundamental neurophysiological processes sensitive to expectancy.Previous research has demonstrated that, when presented with various outcomes of alcohol consumption, heavier drinkers endorse statements that assert positive and arousing effects of alcohol, while lighter drinkers endorse sedating and negative effects of alcohol. Given the sensitivity of the P300 to violation of subjective expectancies, it was hypothesized that P300 amplitude elicited by stimuli violating one's alcohol expectancies (e.g., statements describing sedating effects of alcohol for individuals with high positive expectancies) would be correlated with the participants' alcohol expectancies measured by traditional self-report measures.Participants were presented with statements reflecting a wide range of alcohol outcome effects, which either violated or confirmed the participant's own set of alcohol expectancies, while the ERPs evoked by these stimuli were recorded. As predicted, the P 300 amplitude elicited by negative alcohol expectancy stimuli was positively correlated with the degree of endorsement of positive/arousing expectancies on the self-report measure. That is, the higher the individual's positive/arousing expectancies, the larger the P300 elicited by stimuli asserting the negative effects of alcohol. There was no significant correlation, however, between P300 amplitude elicited by positive alcohol expectancy stimuli and the degree of endorsement of negative/sedating expectancies on the self-report measure.In sum, variations in the amplitude of the P300 were consistent with the model of Alcohol Expectancies: Namely, words imputing negative/sedating effects of alcohol elicited a large P300 in individuals with high but not low positive alcohol expectancies. By indexing the brain's electrophysiological response sensitive to expectancy violations, these findings demonstrate concordance between verbal measures of alcohol expectancies, which by their very nat ure are introspective, and a psychophysiological index of expectancy thought to operate automatically and to be independent of overt responding.
124

文章入力速度向上を目的としたP300 spellerに対する入力文字予測システムの実装とその検討

FURUHASHI, Takeshi, YOSHIKAWA, Tomohiro, TAKAHASHI, Hiromu, TSUGIOKA, Kyoko, 古橋, 武, 吉川, 大弘, 高橋, 弘武, 継岡, 恭子 02 1900 (has links)
No description available.
125

Supporting the link between the locus coeruleus – norepinephrine system, the P300, and the attentional blink

Warren, Christopher M. 27 August 2008 (has links)
This paper provides evidence to support the hypothesis that the locus coeruleus – norephinephrine (LC-NE) system is the neurophysiological basis of both the attentional blink (AB) and the event related potential (ERP) component known as the P300. The LC-NE system is thought to provide a brief burst of processing facilitation in response to motivationally salient events. The AB refers to decreased accuracy for reporting the second of two targets (T1 and T2) inserted into a rapid serial visual presentation (RSVP). The LC-NE account of the AB holds that the AB is the result of a refractory-like period in LC-NE activity. The LC-NE account of the P300 suggests the P300 is the electrophysiological manifestation of the activity of the LC-NE system. I support the three-way link between these different aspects of brain activity by predicting differences in the AB dependent on characteristics of the P300 in response to T1 (T1-P300).
126

Peruvian cinema, national identity and political violence, 1988-2004

Barrow, Sarah Elizabeth January 2007 (has links)
The role of national cinema in shaping, reflecting and contesting a complex national identity that is the site of conflict and struggle is the central interest of this study of contemporary Peruvian cinema, 1988-2004. This project examines the relationship between cinema, state and identity in Peru, with a specific focus on the representation of the political violence between the state and Sendero Luminoso (Shining Path) that began in 1980. It looks in particular at portrayals of important events, characters and consequences of the bloody conflict that for a time threatened to destabilize the nation entirely. It considers these representations in the context of a time of great change for Peruvian society and of transition for Peruvian national cinema, and addresses the relationship between developments in film policy and the formation of Peruvian national identity in cinema. As such, it draws on debates about the nature and function of national cinemas, as well as on discussions between artists, cultural theorists and sociologists about the evolution of peruanidad since the declaration of independence from Spain in the early nineteenth century. Once the main elements of the cinematic and social crises have been explored and established in Chapters Two and Three, the remainder of the project consists of three sets of chronologically ordered analyses of individual films that somehow defied the national cinema crisis, and that provoked debate on both the conflict itself, and on broader questions pertaining to the relationship between national identity and violence. The conclusion considers these films as an interlinked body of cinematic works that share similar themes and concerns. It summarises the issues they tackle, the ideological and formal approaches they take to those issues, the potential social and cultural impact, and their contribution to the crystallization of a Peruvian national identity at the start of the twenty-first century.
127

Processing of Tactile Stimuli in Children with Tourette Syndrome and Attention Deficit Hyperactivity Disorder: An ERP Investigation

Needham, Allison Carissa 16 July 2013 (has links)
Purpose: To investigate and characterize sensory sensitivity in Tourette syndrome (TS) through an evaluation of behaviour, perception and processing of tactile stimuli in children with TS and co-morbid Attention Deficit Hyperactive Disorder (ADHD) compared to typically developing controls (TDC). Methods: Somatosensory evoked P3 potentials were recorded in TS+ADHD and in TDC children aged 6-12 and compared at midline electrodes. Reported sensory sensitivity was measured using the Sensory Profile, while Semmes-Weinstein filaments were used to determine tactile threshold in the same area stimulated during P3 testing. Results: 13 TS+ADHD and 12 TDC were studied. TS+ADHD children reported significantly higher sensory sensitivity (p=.001) and demonstrated a significantly lower tactile threshold (p=.027) than TDC. Furthermore, the amplitude of electrophysiological responses to repetitive tactile stimuli was significantly larger in TS+ADHD (p=.0009). Conclusion: TS+ADHD children are significantly more sensitive to tactile stimulation than controls. ERP differences suggest that central processing alterations could mediate sensory hypersensitivity.
128

Processing of Tactile Stimuli in Children with Tourette Syndrome and Attention Deficit Hyperactivity Disorder: An ERP Investigation

Needham, Allison Carissa 16 July 2013 (has links)
Purpose: To investigate and characterize sensory sensitivity in Tourette syndrome (TS) through an evaluation of behaviour, perception and processing of tactile stimuli in children with TS and co-morbid Attention Deficit Hyperactive Disorder (ADHD) compared to typically developing controls (TDC). Methods: Somatosensory evoked P3 potentials were recorded in TS+ADHD and in TDC children aged 6-12 and compared at midline electrodes. Reported sensory sensitivity was measured using the Sensory Profile, while Semmes-Weinstein filaments were used to determine tactile threshold in the same area stimulated during P3 testing. Results: 13 TS+ADHD and 12 TDC were studied. TS+ADHD children reported significantly higher sensory sensitivity (p=.001) and demonstrated a significantly lower tactile threshold (p=.027) than TDC. Furthermore, the amplitude of electrophysiological responses to repetitive tactile stimuli was significantly larger in TS+ADHD (p=.0009). Conclusion: TS+ADHD children are significantly more sensitive to tactile stimulation than controls. ERP differences suggest that central processing alterations could mediate sensory hypersensitivity.
129

Cited2, an autoregulated transcriptional modulator, in TGF-beta signaling

Chou, Yu-Ting. January 2006 (has links)
Thesis (Ph. D.)--Case Western Reserve University, 2006. / [School of Medicine] Department of Pharmacology. Includes bibliographical references. Available online via OhioLINK's ETD Center.
130

Supporting the link between the locus coeruleus – norepinephrine system, the P300, and the attentional blink

Warren, Christopher M. 27 August 2008 (has links)
This paper provides evidence to support the hypothesis that the locus coeruleus – norephinephrine (LC-NE) system is the neurophysiological basis of both the attentional blink (AB) and the event related potential (ERP) component known as the P300. The LC-NE system is thought to provide a brief burst of processing facilitation in response to motivationally salient events. The AB refers to decreased accuracy for reporting the second of two targets (T1 and T2) inserted into a rapid serial visual presentation (RSVP). The LC-NE account of the AB holds that the AB is the result of a refractory-like period in LC-NE activity. The LC-NE account of the P300 suggests the P300 is the electrophysiological manifestation of the activity of the LC-NE system. I support the three-way link between these different aspects of brain activity by predicting differences in the AB dependent on characteristics of the P300 in response to T1 (T1-P300).

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