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Individual Differences in Subjective Response to Alcohol: Pharmacokinetic and Pharmacodynamic FactorsJanuary 2014 (has links)
abstract: Variability in subjective response to alcohol has been shown to predict drinking behavior as well as the development of alcohol use disorders. The current study examined the extent to which individual differences in alcohol pharmacokinetics impact subjective response and drinking behavior during a single session alcohol administration paradigm. Participants (N = 98) completed measures of subjective response at two time points following alcohol consumption. Pharmacokinetic properties (rate of absorption and metabolism) were inferred using multiple BAC readings to calculate the area under the curve during the ascending limb for absorption and descending limb for metabolism. Following the completion of the subjective response measures, an ad-libitum taste rating task was implemented in which participants were permitted to consume additional alcoholic beverages. The amount consumed during the taste rating task served as the primary outcome variable. Results of the study indicated that participants who metabolized alcohol more quickly maintained a greater level of subjective stimulation as blood alcohol levels declined and reported greater reductions in subjective sedation. Although metabolism did not have a direct influence on within session alcohol consumption, a faster metabolism did relate to increased ad-libitum consumption indirectly through greater acute tolerance to sedative effects and greater maintenance of stimulant effects. Rate of absorption did not significantly predict subjective response or within session drinking. The results of the study add clarity to theories of subjective response to alcohol, and suggest that those at highest risk for alcohol problems experience a more rapid reduction in sedation following alcohol consumption while simultaneously experiencing heightened levels of stimulation. Variability in pharmacokinetics, namely how quickly one metabolizes alcohol, may be an identifiable biomarker of subjective response and may be used to infer risk for alcohol problems. / Dissertation/Thesis / Doctoral Dissertation Psychology 2014
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Subjective Response to Noise in Summer and WinterSturk, Michael E. 11 1900 (has links)
<p> Previous studies on subjective response to noise have been conducted during the summer months. These studies have served as the basis for noise standards and legislation; therefore an implicit assumption has been made that response to noise is similar in summer and winter. Whether or not this applies equally well to the winter months, which represent approximately one-half of the year, warranted investigation. Data on summer and winter responses to comparable noise levels were collected and hypotheses were tested for differences in response to overall noise levels and to specific noise sources. The results indicated that there were no significant differences between summer and winter responses.</p> / Thesis / Master of Arts (MA)
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Proposed automobile steering wheel test method for vibrationJeon, Byung Ho January 2010 (has links)
This thesis proposes a test method for evaluating the perceived vibration which occurs at the driver's hand in automotive steering wheel interface. The objective of the research was to develop frequency weightings for quantifying the human perception of steering wheel hand-arm vibration. Family of frequency weightings were developed from equal sensation curves obtained from the psychophysical laboratory experimental tests. The previous literature suggests that the only internationally standardised frequency weighting Wh is not accurate to predict human perception of steering wheel hand-arm vibration (Amman et. al, 2005) because Wh was developed originally for health effects, not for the human perception. In addition, most of the data in hand-arm vibration are based upon responses from male subjects (Neely and Burström, 2006) and previous studies based only on sinusoidal stimuli. Further, it has been continuously suggested by researchers (Gnanasekarna et al., 2006; Morioka and Griffin, 2006; Ajovalasit and Giacomin, 2009) that only one weighting is not optimal to estimate the human perception at all vibrational magnitudes. In order to address these problems, the investigation of the effect of gender, body mass and the signal type on the equal sensation curves has been performed by means of psychophysical laboratory experimental tests. The test participants were seated on a steering wheel simulator which consists of a rigid frame, a rigid steering wheel, an automobile seat, an electrodynamic shaker unit, a power amplifier and a signal generator. The category-ratio Borg CR10 scale procedure was used to quantify the perceived vibration intensity. A same test protocol was used for each test and for each test subject. The first experiment was conducted to investigate the effect of gender using sinusoidal vibration with 40 test participants (20 males and 20 females). The results suggested that the male participants provided generally lower subjective ratings than the female participants. The second experiment was conducted using band-limited random vibration to investigate the effect of signal type between sinusoidal and band-limited random vibration with 30 test participants (15 males and 15 females). The results suggested that the equal sensation curves obtained using random vibration were generally steeper and deeper in the shape of the curves than those obtained using sinusoidal vibration. These differences may be due to the characteristics of random vibration which produce generally higher crest factors than sinusoidal vibration. The third experiment was conducted to investigate the effect of physical body mass with 40 test participants (20 light and 20 heavy participants) using sinusoidal vibration. The results suggested that the light participants produced generally higher subjective ratings than the heavy participants. From the results it can be suggested that the equal sensation curves for steering wheel rotational vibration differ mainly due to differences of body size rather than differences of gender. The final experiments was conducted using real road signals to quantify the human subjective response to representative driving condition and to use the results to define the selection method for choosing the adequate frequency weightings for the road signals by means of correlation analysis. The final experiment was performed with 40 test participants (20 light and 20 heavy participants) using 21 real road signals obtained from the road tests. From the results the hypothesis was established that different amplitude groups may require different frequency weightings. Three amplitude groups were defined and the frequency weightings were selected for each amplitude group. The following findings can be drawn from the research: • the equal sensation curves suggest a nonlinear dependency on both the frequency and the amplitude. • the subjective responses obtained from band-limited random stimuli were steeper and the deeper in the shape of the equal sensation curves than those obtained using sinusoidal vibration stimuli. • females provided higher perceived intensity values than the males for the same physical stimulus at most frequencies. • light test participants provided higher perceived intensity than the heavy test participants for the same physical stimulus at most frequencies. • the equal sensation curves for steering wheel rotational vibration differ mainly due to differences in body size, rather than differences of gender. • at least three frequency weightings may be necessary to estimate the subjective intensity for road surface stimuli.
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Anxiety and Subjective Response to Alcohol: Moderating Effects of Drinking Context and Mediation by Cortisol Response to AlcoholJanuary 2018 (has links)
abstract: Anxiety disorder diagnosis is a risk factor for alcohol use disorders (AUDs), but mechanisms of risk are not well understood. Studies show that anxious individuals receive greater negative reinforcement from alcohol when consumed prior to a stressor, but few studies have examined whether anxious individuals receive greater negative (or positive) reinforcement from alcohol in a general drinking context (i.e., no imminent stressor). Previous studies have also failed to examine possible moderating effects of specific drinking contexts (e.g., drinking in a group or alone). Finally, no studies have investigated mediating variables that might explain the relationship between anxiety and reinforcement from alcohol, such as physiological response to alcohol (e.g., cortisol response). Data for this study were drawn from a large alcohol administration study (N = 447) wherein participants were randomized to receive alcohol (target peak BAC: .08 g%) or placebo in one of four contexts: group simulated bar, solitary simulated bar, group sterile laboratory, solitary sterile laboratory. It was hypothesized that anxiety would be associated with positive subjective response (SR) under alcohol (above and beyond placebo), indicating stronger reinforcement from alcohol. It was also hypothesized that social and physical drinking context would moderate this relationship. Finally, it was hypothesized that anxiety would be associated with a blunted cortisol response to alcohol (compared to placebo) and this blunted cortisol response would be associated with stronger positive SR and weaker negative SR. Results showed that anxiety was not associated with positive SR in the full sample, but drinking context did moderate the anxiety/SR relationship in most cases (e.g., anxiety was significantly associated with positive SR (stimulation) under placebo in solitary contexts only). There was no evidence that cortisol response to alcohol mediated the relationship between anxiety and SR. This study provides evidence that anxious drinkers expect stronger positive reinforcement from alcohol in solitary contexts, which has implications for intervention (e.g., modification of existing interventions like expectancy challenge). Null findings regarding cortisol response suggest alcohol’s effect on cortisol response to stress (rather than cortisol response to alcohol consumption) may be more relevant for SR and drinking behavior among anxious individuals. / Dissertation/Thesis / Doctoral Dissertation Psychology 2018
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Human emotional response to automotive steering wheel vibration : development of a driver emotional semantic scaleShabani, Arber January 2016 (has links)
The 21st century automobile has become more than just a simple tool for transportation and more of a brand image or a way for drivers to express their personal taste. This has made it increasingly important for automotive manufacturers to design the driver experience and driver feeling so as to tailor their preferences and interests. Currently there is not enough information on how to design or brand the communication of meaningful feedback from the automobile to the driver. With the development of new advanced technologies such as electric steer-by-wire systems or electric automobiles, the need to provide meaningful feedback to the driver plays a central role in the experience of using the new driving technology. Thus it is important to understand how to assess the emotional response to the stimuli reaching the driver so to be able to optimise at later stage the perceived experience. Steering wheel vibration feedback plays an important role for the driver’s control input when driving. There is currently a lack of research on the formal assessment criteria of driver emotional response used to define automotive steering wheel vibration feedback, therefore this thesis proposes a newly Driver Emotional Semantic (DES) Scale to answer the research question: “How can the emotional response to steering wheel vibration be assessed?”. This study starts with a comparison of a questionnaire survey (Exp.1) and a laboratory test (Exp.2) to identify if a correlation exists between the emotional ratings measured from the expected driver’s perception of the vibration and the experienced emotional feeling of steering wheel vibration. The work then defines a semantic scale to capture the vibrational vocabulary used by the driver to express their feeling of perceived vibration during real-road driving scenarios. Experiment 3 was therefore carried out to gather the underlying semantic descriptors used by drivers during driving scenarios. To test the reliability of the descriptive pairs of the DES rating scale developed, two evaluations of the assessment criteria were carried out: in real road scenarios (Exp.4) and laboratory test setting (Exp.5). Current research findings of this thesis suggest that the consistency of the scale dimensions found in the field study has captured with greater accuracy the driver semantic experience of automotive steering wheel vibration character as compared to the laboratory experiment dimensionality. Results suggest that the main vibrotactile semantic descriptors to assess the human emotional response to automotive steering wheel vibration were found to be four: pleasant, smooth, sharp and powerful. The final proposed DES scale could help automotive research and industry determine and customise the aspects of the automobile towards drivers’ preferences of felt experience.
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Contextual Effects on Relations among Alcohol Outcome Expectancies, Subjective Response, and Drinking BehaviorJanuary 2016 (has links)
abstract: Positive alcohol outcome expectancies (AOEs) are consistent longitudinal predictors of later alcohol use; however, exclusion of solitary drinking contexts in the measurement of AOEs may have resulted in an underestimation of the importance of low arousal positive (LAP) effects. The current study aimed to clarify the literature on the association between AOEs and drinking outcomes by examining the role of drinking context in AOE measurement. Further, exclusion of contextual influences has also limited understanding of the unique effects of AOEs relative to subjective responses (SR) to alcohol. The present study addressed this important question by exploring relations between AOEs and SR when drinking context was held constant across parallel measures of these constructs. Understanding which of these factors drives relations between alcohol effects and drinking behavior has important implications for intervention. After conducting confirmatory factor analysis (CFA) and tests of measurement invariance for the AOE and SR measures, 4 aims collectively examined the role of context in reporting of AOEs (Aims 1 and 2), the extent to which context specific AOEs uniquely relate to drinking outcomes (Aim 3), and the importance of context effects on correspondence between AOEs and SR (Aim 4). Results of Aims 1 and 2 demonstrated that participants are imagining contexts when reporting on measures of AOEs that do not specify the context, and found significant mean differences in high and low arousal positive AOEs across contexts. Contrary to the hypotheses of Aim 3, context-specific AOEs were not significantly associated with drinking behavior. Results of Aim 4 indicated that while LAP AOEs for both unspecified and solitary contexts were associated with LAP SR in a solitary setting, unspecified context AOEs had a stronger relation than the solitary context AOEs. No significant relations between high arousal positive (HAP) AOEs and HAP SR emerged. The findings suggest that further investigation of the relation between context-specific AOEs and drinking outcomes/SR is warranted. Future studies of these hypotheses in samples with a wider range of drinking behavior, or at different stages of alcohol involvement, will elucidate whether mean level differences in context specific AOEs are important in understanding alcohol related outcomes. / Dissertation/Thesis / Doctoral Dissertation Psychology 2016
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Alcohol Expectancies versus Subjective Response as Mediators of Disposition in the Acquired Preparedness ModelJanuary 2012 (has links)
abstract: Levels of heavy episodic drinking peak during emerging adulthood and contribute to the experience of negative consequences. Previous research has identified a number of trait-like personality characteristics that are associated with drinking. Studies of the Acquired Preparedness Model have supported positive expectancies, and to a lesser extent negative expectancies, as mediators of the relation between trait-like characteristics and alcohol outcomes. However, expectancies measured via self-report may reflect differences in learned expectancies in spite of similar alcohol-related responses, or they may reflect true individual differences in subjective responses to alcohol. The current study addressed this gap in the literature by assessing the relative roles of expectancies and subjective response as mediators within the APM in a sample of 236 emerging adults (74.7% male) participating in a placebo-controlled alcohol challenge study. The study tested four mediation models collapsed across beverage condition as well as eight separate mediation models with four models (2 beverage by 2 expectancy/subjective response) for each outcome (alcohol use and alcohol-related problems). Consistent with previous studies, SS was positively associated with alcohol outcomes in models collapsed across beverage condition. SS was also associated with positive subjective response in collapsed models and in the alcohol models. The hypothesized negative relation between SS and sedation was not significant. In contrast to previous studies, neither stimulation nor sedation predicted either weekly drinking or alcohol-related problems. While stimulation and alcohol use appeared to have a positive and significant association, this relation did not hold when controlling for SS, suggesting that SS and stimulation account for shared variability in drinking behavior. Failure to find this association in the placebo group suggests that, while explicit positive expectancies are related to alcohol use after controlling for levels of sensation seeking, implicit expectancies (at least as assessed by a placebo manipulation) are not. That the relation between SS and stimulation held only in the alcohol condition in analyses separate by beverage condition indicates that sensation seeking is a significant predictor of positive subjective response to alcohol (stimulation), potentially above and beyond expectancies. / Dissertation/Thesis / M.A. Psychology 2012
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Investigating the Combined Effects of Alcohol Expectancies and Subjective Response on Future Drinking: An Interaction ApproachJanuary 2020 (has links)
abstract: Past research suggests that both Alcohol Expectancies and Subjective Response are strong predictors of drinking. However, most studies do not account for the shared variance or relations between the two. Social cognitive and expectancy theories suggest that cognitions may distort reality, creating a discrepancy between expected and subjective effects. Only one study has tested the effects of such discrepancies (Morean et al., 2015), but that study was cross-sectional, making it impossible to determine the direction of effects. As such, the present study sought to test prospective associations between expectancy-subjective response interactions and future drinking behavior. Participants (N=448) were randomly assigned to receive alcohol (target blood alcohol alcohol =.08 g%) or placebo, with 270 in the alcohol condition. Alcohol expectancies and subjective response were assessed across the full range of affective space of valence by arousal. Hierarchical regression tested whether expectancies, subjective response, and their interaction predicted follow-up drinking in 258 participants who reached a blood alcohol curve of >.06 (to differentiate blood alcohol curve limbs). Covariates included gender, age, drinking context, and baseline drinking. High arousal subjective response was tested on the ascending limb and low arousal subjective response on the descending limb. High arousal positive expectancies and subjective response interacted to predict future drinking, such that mean and low levels of high arousal positive subjective response were associated with more drinking when expectancies were higher. High arousal negative expectancies and subjective response also interacted to predict future drinking, such that high levels of high arousal negative subjective response marginally predicted more drinking when expectancies were lower. There were no interactions between low arousal positive or low arousal negative expectancies and subjective response. Results suggest that those who expected high arousal positive subjective response but did not receive many of these effects drank more, and those who did not expect to feel high arousal negative subjective response but did in fact feel these effects also drank more. The results suggest that challenging inaccurate positive expectancies and increasing awareness of true negative subjective response may be efficacious ways to reduce drinking. / Dissertation/Thesis / Masters Thesis Psychology 2020
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