THE EFFECTS OF ALCOHOL-RELATED VISUAL STIMULI ON INHIBITORY CONTROL AND ATTENTIONAL BIAS: TESTING THE ROLES OF CLASSICAL CONDITIONING AND SEMANTIC PRIMING

Alcohol research has shown that alcohol-related stimuli can disrupt behavioral control and attract more attention in alcohol drinkers. Stimuli typically used in tasks assessing these mechanisms are likely representative of an individual\u27s history. Responses to visual stimuli that no longer closely resemble an individual\u27s history may help shed light on whether these behaviors are due to classical conditioning or processes such as semantic priming. Hypotheses were tested using typical visual stimuli and modified, abstract versions in these tasks. 41 participants were exposed to these stimuli types while using a visual dot probe task. The difference in degree of attentional bias between real and modified stimuli was determined using gaze time. Individuals participated in two versions of the attentional bias-behavioral activation (ABBA) task. Proportion of inhibitory failure differences between versions was examined for the effects of stimuli modification on behavioral control. Results demonstrated that the sample did not exhibit an attentional bias to alcohol. Visual probe results yielded no differences between real and modified stimuli on attentional bias. ABBA performance indicated no differences as a result of image abstraction or stimuli type. Reasons for these findings and comparisons to similar research inquiries using the tasks the current thesis utilized were explored

ATTENTIONAL BIAS TO ALCOHOL IN AN IN VIVO SETTING

The phenomenon of attentional bias to alcohol, where drinkers demonstrate a preference in allocating visual attention towards alcohol-related stimuli rather than neutral stimuli, is well-established. Studies detecting this phenomenon typically utilize computer-administered stimulus presentation tasks such as the visual dot probe task. Despite their frequency of use, these tasks do not represent the ways in which individuals typically encounter alcohol outside of the laboratory. Typical environments where alcohol is present allow individuals to move about freely and encounter alcohol while also being exposed to many other stimuli. This dissertation sought to implement a novel approach to assessing attentional bias in vivo, and identify how alcohol consumption might influence such in vivo attentional bias. This two-study dissertation utilized an in vivo task where participants looked freely around a room representing a recreational setting containing numerous objects while portable eye-tracking glasses monitored what an individual looked at and for how long. Target items of alcohol and neutral beverages were placed throughout the environment and fixation time spent on these objects was recorded. The first study of this dissertation examined attentional bias to alcohol-related objects across two identical testing sessions to understand the impact of novelty on allocation of in vivo attention. The second study tested individuals using the same in vivo assessment following a 0.30 g/kg dose of alcohol, a 0.65 g/kg dose of alcohol and a placebo. Participants also completed the visual dot probe task in order to measure and compare their attentional bias in a more traditionally implemented task to the novel in vivo approach. Results from the first study indicate that as the novelty of stimuli begins to wane and habituation to neutral stimuli occurs, attentional bias to alcohol-related objects emerges. This attentional bias was shown to be related to drinking habits, where heavier drinkers demonstrated increased attentional bias. The second study in this research found no discernible effect of alcohol consumption on in vivo attentional bias, but did identify a satiating effect of consumption on bias as measured by the visual dot probe task. Additional visual dot probe findings suggest the specificity of the effect of alcohol consumption on attentional bias. Together, these findings help inform whether there is benefit in utilizing an ecological model of measuring attentional bias and how the phenomenon might be measured in laboratory settings in the future

Measuring Heightened Attention to Alcohol in a Naturalistic Setting: A Validation Study

Attentional bias to alcohol-related stimuli is believed to be an important contributor to the development and maintenance of drug abuse. There is a considerable body of research examining attentional bias, much of which has typically utilized image-display tasks as a means to assess the phenomenon. Little, however, is known about the nature of this bias in an individual’s natural environment. The current study sought to implement a novel approach to assessing attentional bias in vivo. Participants wore portable eye-tracking glasses that recorded video from their point of view and measured fixation time to objects they observed. They entered a room that was designed to represent a recreational setting in which both alcohol- and nonalcoholic-neutral beverages were placed along with other stimuli. In two different testing sessions, participants were free to visually explore the room. Participants showed similar fixation times to alcohol and neutral beverages during Session 1. Attentional bias to alcoholic beverages was observed in Session 2 because fixation time decreased to neutral but not to alcoholic beverages. The magnitude of attentional bias was positively associated with drinking habits, with heavier drinkers demonstrating a higher degree of bias to alcohol. These findings provide an ecological model of how attentional bias can develop as the net result of attention being sustained to alcoholic stimuli while diminishing to other stimuli over time

“Not in their right mind”: the relation of psychopathology to the quantity and quality of creative thought

This is the published version. Copyright 2014 FrontierThe empirical link between psychopathology and creativity is often correlational and fraught with suspiciously causal interpretations. In this paper, we review research in favor of the position that certain forms of psychopathology that profoundly affect the neural substrates for rule-based thought (e.g., schizophrenia, bipolar disorder) can significantly influence the quantity of creative production. Because highly productive individuals, irrespective of psychopathology, often produce work of greater quality, it seems that such an increase in the quantity of one’s output positively affects the likelihood of generating those statistically rare acts and achievements identified and celebrated as creative. We consider evidence that offers support for such a claim. In addition, we explore findings from neuroscience that can address how a neural mechanism, the flexibility of which relies on tradeoffs between rule-based (e.g., prefrontal cortex) and stimulus-based (e.g., sensorimotor cortex) brain regions, is influenced by psychopathology in ways that can alter dramatically the quantity and quality of creative output

Experimental analysis of thread movement in bolted connections due to vibrations

The objective of this study was to identify the main design parameters contributing to loosening of bolts due to vibration and to identify their relative importance and degree of contribution to bolt loosening. Vibration testing was conducted on a shaketable with a controlled-random input in the dynamic testing laboratory of the Structural Test Division of MSFC. Test specimens which contained one test bolt were vibrated for a fixed amount of time and percentage of pre-load loss was measured. Each specimen tested implemented some combination of eleven design parameters as dictated by the design of experiment methodology employed. The eleven design parameters were: bolt size (diameter), lubrication on bolt, hole tolerance, initial pre-load, nut locking device, grip length, thread pitch, lubrication between mating materials, class of fit, joint configuration and mass of configuration. These parameters were chosen for this experiment because they are believed to be the design parameters having the greatest impact on bolt loosening. Two values of each design parameter were used and each combination of parameters tested was subjected to two different directions of vibration and two different g-levels of vibration. One replication was made for each test to gain some indication of experimental error and repeatability and to give some degree of statistical credibility to the data, resulting in a total of 96 tests being performed. The results of the investigation indicated that nut locking devices, joint configuration, fastener size, and mass of configuration were significant in bolt loosening due to vibration. The results of this test can be utilized to further research the complex problem of bolt loosening due to vibration

Mars-GRAM 2010: Improving the Precision of Mars-GRAM

It has been discovered during the Mars Science Laboratory (MSL) site selection process that the Mars Global Reference Atmospheric Model (Mars-GRAM) when used for sensitivity studies for Thermal Emission Spectrometer (TES) MapYear=0 and large optical depth values, such as tau=3, is less than realistic. Mars-GRAM's perturbation modeling capability is commonly used, in a Monte-Carlo mode, to perform high fidelity engineering end-to-end simulations for entry, descent, and landing (EDL). Mars-GRAM 2005 has been validated against Radio Science data, and both nadir and limb data from TES. Traditional Mars-GRAM options for representing the mean atmosphere along entry corridors include: (1) TES mapping year 0, with user-controlled dust optical depth and Mars-GRAM data interpolated from NASA Ames Mars General Circulation Model (MGCM) results driven by selected values of globally-uniform dust optical depth, or (2) TES mapping years 1 and 2, with Mars-GRAM data coming from MGCM results driven by observed TES dust optical depth. From the surface to 80 km altitude, Mars-GRAM is based on NASA Ames MGCM. Above 80 km, Mars-GRAM is based on the University of Michigan Mars Thermospheric General Circulation Model (MTGCM). MGCM results that were used for Mars-GRAM with MapYear=0 were from a MGCM run with a fixed value of tau=3 for the entire year at all locations. This choice of data has led to discrepancies that have become apparent during recent sensitivity studies for MapYear=0 and large optical depths. Unrealistic energy absorption by time-invariant atmospheric dust leads to an unrealistic thermal energy balance on the polar caps. The outcome is an inaccurate cycle of condensation/sublimation of the polar caps and, as a consequence, an inaccurate cycle of total atmospheric mass and global-average surface pressure. Under an assumption of unchanged temperature profile and hydrostatic equilibrium, a given percentage change in surface pressure would produce a corresponding percentage change in density at all altitudes. Consequently, the final result of a change in surface pressure is an imprecise atmospheric density at all altitudes

The Next Generation of Mars-GRAM and Its Role in the Autonomous Aerobraking Development Plan

The Mars Global Reference Atmospheric Model (Mars-GRAM) is an engineering-level atmospheric model widely used for diverse mission applications. Mars-GRAM 2010 is currently being used to develop the onboard atmospheric density estimator that is part of the Autonomous Aerobraking Development Plan. In previous versions, Mars-GRAM was less than realistic when used for sensitivity studies for Thermal Emission Spectrometer (TES) MapYear=0 and large optical depth values, such as tau=3. A comparison analysis has been completed between Mars-GRAM, TES and data from the Planetary Data System (PDS) resulting in updated coefficients for the functions relating density, latitude, and longitude of the sun. The adjustment factors are expressed as a function of height (z), Latitude (Lat) and areocentric solar longitude (Ls). The latest release of Mars-GRAM 2010 includes these adjustment factors that alter the in-put data from MGCM and MTGCM for the Mapping Year 0 (user-controlled dust) case. The greatest adjustment occurs at large optical depths such as tau greater than 1. The addition of the adjustment factors has led to better correspondence to TES Limb data from 0-60 km as well as better agreement with MGS, ODY and MRO data at approximately 90-135 km. Improved simulations utilizing Mars-GRAM 2010 are vital to developing the onboard atmospheric density estimator for the Autonomous Aerobraking Development Plan. Mars-GRAM 2010 was not the only planetary GRAM utilized during phase 1 of this plan; Titan-GRAM and Venus-GRAM were used to generate density data sets for Aerobraking Design Reference Missions. These data sets included altitude profiles (both vertical and along a trajectory), GRAM perturbations (tides, gravity waves, etc.) and provided density and scale height values for analysis by other Autonomous Aero-braking team members

Biomonitoring Study of a Constructed Wetland Site Treating Acid Mine Drainage

Acid mine drainage (AMD) from an underground coal mine in the Jones Branch watershed in McCreary County, KY, substantially reduced water quality in Jones Branch. Downstream from the mine seeps, the pH was routinely below 4.5 and concentrations of most heavy metals, especially iron, were elevated. A cattail wetland (1,022 m2) was constructed on Jones Branch in 1989 to obviate the effects of the AMD. Monthly chemical monitoring was performed on the water from above, from below, and from the 26 cells within the wetland. Based on chemical monitoring, the wetland initially improved water quality, increasing the pH and removing substantial amounts of heavy metals. Beginning in the spring of 1991, water quality at the wetland outfall began to decline, and has not improved to date. To augment the chemical monitoring, a biomonitoring study was initiated in the spring of 1990. Acute 48-hr static tests were conducted with newly hatched fathead minnows (Pimephales promelas). Water samples were obtained from the seep inlet, four cells within the wetland, and from Jones Branch above and below the wetland site. Median lethal concentration (LC50) values determined monthly reflect the decline in water quality at the outfall over time. However, within the wetland there was gradual improvement in survivability from inlet to outlet, providing evidence that the wetland was responsible for a modest improvement in water quality

The Aquatic Toxicity of Organic Compounds to Embryo-Larval Stages of Fish and Amphibians

Aquatic toxicity tests were conducted on 11 organic compounds considered hazardous to water resources. The toxicity of each compound was evaluated using embryo-larval stages of two to eight fish and amphibian species. Exposure was initiated at fertilization and maintained through 4 days posthatching. The animal test species exhibited varying degrees of sensitivity to the selected toxicants. Combined frequencies for mortality and teratogenesis at 4 days posthatching gave LC50 ranges of 3.66 to 8.25 mg/L for benzene, 1.16 to 22.42 mg/L for carbon tetrachloride, 0.11 to 1.20 mg/L for chlorobenzene, 2.03 to \u3e 68 mg/L for chloroform, 3.01 to 5.56 mg/L for 1,2-dichlorobenzene, 2.54 to .34 mg/L for 1,2-dichloroethane, 13.16 to \u3e 48 mg/L for methylene chloride, 0.002 to 0.64 mg/L for nitrobenzene, 0.04 to .32 mg/L for phenol, 0.02 to 0.85 mg/L for toluene, and 3.53 to 3.77 mg/L for m-xylene. The species which exhibited the greatest susceptibility to organic compounds were the rainbow trout, Rana pipiens, and Rana temporaria. The more sensitive amphibian species generally were those which normaly are restricted to aquatic or moist terrestrial habitats, whereas the more tolerant amphibians included those semi-aquatic and terrestrial species which appear to be more broadly adapted ecologically. Of the 11 test compounds, nitrobenzene, toluene, chlorobenzene, and phenol were the most toxic. The least toxic organics included dichloroethane and methylene chloride. For three chlorinated alkanes, including methylene chloride (CH2Cl2), chloroform (CHCl3), and carbon tetrachloride (CCl4), toxicity was found to 1ncrease with the degree of chlorination. Concerning several aromatic hydrocarbons, benzene always was found to be less toxic than its monosubstituted analogs. Toxicity of the 11 compounds was further evaluated by calculating toxicant concentrations which produced embryo-larval mortality and/or teratogenesis at frequencies of 10% (LC10) and 1% (LC1). The LC values, used to estimate toxicity thresholds, ranged from \u3c 0.l for nitrobenzene to 69.9 μg/L for methylene chloride. A limited number of toxicity tests were performed to determine whether embryo-larval bioassays are suitable to assess effects of transitory chemical exposures, such as those resulting from intermittent discharges or accidental spills of chemicals into water resources. Results indicated that Rana pipiens embryos were sufficiently sensitive to quantify effects produced by short-term exposures to chloroform. Animals tested during the earliest embryonic stage appeared to be less tolerant than organisms exposed later in development

Explaining Africa’s public consumption procyclicality : revisiting old evidence

This paper compiles a novel dataset of time-varying measures of government consumption cyclicality for a panel of 46 African economies between 1960 and 2014. Government consumption has, generally, been highly procyclical over time in this group of countries. However, sample averages hide serious heterogeneity across countries with the majority of them showing procyclical behavior despite some positive signs of graduation from the “procyclicality trap” in a few cases. By means of weighted least squares regressions, we find that more developed African economies tend to have a smaller degree of government consumption procyclicality. Countries with higher social fragmentation and those are more reliant on foreign aid inflows tend to have a more procyclical government consumption policy. Better governance promotes counter- cyclical fiscal policy whileincreased democracy dampens it. Finally, some fiscal rules are important in curbing the procyclical behavior of government consumption.info:eu-repo/semantics/publishedVersio