In everyday life our eyes are exposed to massive amounts of visual stimuli. However, even though the stimuli’s features grab our attention, we have a natural tendency to focus on the centre of the scenes. This central spatial bias is not steady; in fact, while freely viewing a scene, the eyes shift towards the left for two seconds and then return to the centre (Ossandón, Onat, & König, 2014). The leftward spatial bias has also been reported in other behavioural studies, suggesting the role of the lateralization of the attention network. The attention network is activated dominantly on the right hemisphere when detecting new/novel stimuli, causing stronger effects on the contralateral (left) hemispatial side. Hence, in this thesis a series of behavioral studies were conducted using an eye-tracking technique to modulate the leftward spatial bias using different types of primes. Five different eye-tracking experiments were performed in the Neurobiopsychology (NBP) Department at Osnabrück University to investigate the interplay between the horizontal spatial bias and multiple different primes displayed prior to the presentation of images in free viewing tasks. The goal of Experiment 1 was to investigate if different reading directions can alter the leftward spatial bias. The results showed that native right-to-left (RTL) readers showed RTL spatial bias after reading RTL texts and left-to-right (LTR) spatial bias after reading LTR texts. This result suggests the dynamic role that the reading direction has on modifying the horizontal spatial bias. On the other hand, native LTR readers who learned RTL languages later in life showed a leftward spatial bias after reading both LTR and RTL texts. While these results suggest the crucial role of mastering RTL languages in modulating the spatial bias, a larger sample size is required to confirm these findings. The aim of Experiment 2 was to investigate if the reader’s second language has a different effect than his/her native language on the leftward spatial bias. Compared to native language LTR texts, LTR/LTR bilinguals demonstrated a slight increase in the leftward spatial bias after reading second language LTR texts. This finding demonstrates the effect that the second language has on enhancing and reinforcing the leftward spatial bias. The goal of Experiment 3 was to study the difference between habitual reading and non-habitual reading (mirrored reading) on the leftward spatial bias. LTR bilinguals read LTR and mirrored LTR (mLTR) texts prior to image exploration and showed a strong leftward bias after reading both texts. The outcome of this experiment suggests that there is an influence of habitual (normal LTR) reading and not of non-habitual (mLTR) reading on the horizontal spatial bias, even though the same language was used in the primes. Experiment 4 investigated if the oculomotor control of the eye movement, without reading, can modulate the leftward spatial bias as in habitual reading. Thus, LTR and RTL moving-dot primes without reading were presented prior to image exploration, mimicking the readers’ eye movement. Native LTR readers showed a leftward bias after primed with LTR and RTL moving-dots. However, in a pilot study within this experiment, native RTL bilinguals demonstrated rightward bias after RTL moving-dots and a weak leftward bias after LTR moving-dots. These findings strengthen the effect of the habitual reading direction and exclude the role of language in reshaping the leftward horizontal bias. Following this, Experiment 5 studied the effect of different factors, including age, gender, first language, second language, second language proficiency, and age of second language acquisition, on the magnitude of the horizontal spatial bias. This Experiment is considered an extension of Experiment 1 in order to study the interindividual differences among native RTL readers after reading RTL texts in a free viewing task. Compared to the native LTR/LTR readers of Experiment 2, the rightward spatial bias among individuals of native RTL readers was strong and profound, but with a large variance of the measurements, suggesting inter-individual differences. This study found no correlation between the magnitude of the RTL spatial bias and the age, gender, first language, second language, second language proficiency, and age of second language acquisition of the participants. Thus, these findings strengthen the profound role that the habitual reading direction has on the RTL spatial bias, regardless of the biological and cultural variables mentioned above. Overall, the thesis proves that the RTL habitual reading direction has a flexible role in modulating the leftward spatial bias (Experiment 1). In addition, the LTR habitual scanning direction can reinforce the leftward bias among native LTR readers to a certain degree (Experiment 2). Yet, non-habitual reading process (Experiment 3) and oculomotor control without language involvement (Experiment 4) showed no influence on the horizontal spatial bias. Moreover, there was no evidence to suggest whether or not age, gender, first language, second language, second language proficiency, and age of second language acquisition influence the magnitude of the rightward horizontal spatial bias (Experiment 5). This leads to the conclusion that forming a habit of scanning direction is a strong factor in changing the natural spatial bias. Furthermore, even though no correlation was found between several biological/cultural factors and the magnitude of the RTL spatial bias, certain speculations can be proposed. First, the strength of the LTR and RTL scanning habits among RTL individuals could lead to an antagonizing effect and yield to interindividual differences. Second, the interindividual differences at the structural and functional cortical level among healthy individuals could cause interindividual differences in the horizontal spatial bias. Third, the narrow group sample of the LTR readers could lead to a small variance in comparison to the diversity of the RTL group sample. Overall, these five experiments have shed light on the dynamic effect of reading direction on the natural spatial bias and opened the door for potential cross-cultural studies regarding visuospatial attention.

Trichotillomania is defined as recurrent pulling of one’s hair that results in distress and negative effects on general functioning and quality of life. Estimates of trichotillomania lifetime prevalence generally range from approximately 1% to 3% and it is likely as common as disorders such as obsessive-compulsive disorder and agoraphobia. Yet, quality treatment for trichotillomania is often difficult to find as many mental health professionals are uninformed about the disorder and its treatment. Moreover, mental health services in general are inaccessible to many with estimates suggesting that 96.5 million people do not have access to adequate services. The use of telepsychology has been an effective method for disseminating treatment services for a variety of mental health conditions. However, no research has examined the effectiveness of telepsychology to treat trichotillomania. The current study reports the results of a randomized clinical trial of Acceptance and Commitment Therapy Enhanced Behavior Therapy for the treatment of trichotillomania delivered by way of telepsychology. The study compared an active treatment condition (n = 12) to a waitlist control condition (n = 10). Results showed significant reductions in hair pulling severity from pre- to post-treatment compared to the waitlist condition. Participants in the waitlist condition received the same treatment as participants in the treatment condition following the waitlist period. All participants were then combined to examine overall treatment effects from pre-treatment to a 12-week follow-up. The effect of treatment on hair pulling severity was still significant at follow-up, however the effect was not as strong as at post-treatment. Conversely, the effect on quality of life was maintained and even increased following post-treatment. Additional measures of psychological flexibility, perceived shame, and valued action also saw significant changes from pre-treatment to follow-up. The findings demonstrate that telepsychology is a viable option to disseminate treatment for trichotillomania. Implications, limitations, and future research directions are discussed.

Indiana University-Purdue University Indianapolis (IUPUI) / Habit expression is emerging as a theory of addiction: subjects begin to use drugs to attain positive reinforcing effects but continue to use in spite of negative effects because the behavior becomes habitual, and therefore divorced from its outcome. Many studies have shown that a history of drug and alcohol use lead to expedited acquisition of a habit, but the acute effects of these drugs on behavior is still unknown. Behaviors that result from acute intoxication, such as increased aggression, risky sexual behavior, and impaired judgment, could be interpreted as habitual: actions performed without regard for the outcome. Therefore, we studied the transition from goal-directed to habitual behavior, when a response is made regardless of outcome value, and how acute intoxication of ethanol (EtOH), amphetamine (AMP), nicotine (NIC), and yohimbine (YOH) affect the resulting behavior. Through a series of four experiments, selectively bred crossed High Alcohol Preferring (cHAP) mice were trained on an operant task to self-administer 1% banana solution, which was subsequently devalued via LiCl CTA. EtOH (1 & 1.5 g/kg), AMP (2.0 mg/kg), NIC (0.5 mg/kg), YOH (1.0 mg/kg), or SAL were administered prior to baseline and post-devaluation tests. We found that acute EtOH at 1- and 1.5-g/kg doses facilitated the expression of a habit, whereas all other pretreatments resulted in devaluation. These data may indicate a unique role for EtOH in facilitating the retrieval of habitual over outcome-based associations. This could shed light on why intoxicated individuals display impaired judgment and a mechanism by which relapse after a period of abstinence can occur.

No description available.

The present study investigated the effectiveness of health related feedback as a positive reinforcer of abstinence from smoking during the 11 week period following cessation. Fifty-three subjects were randomly assigned to one of three groups: (a) maintenance program plus health related feedback (MF), (b) maintenance program only (M) and, (c) discussion control (D). All groups received an aversive treatment for smoking after which the MP group received coping skills raining and several forms of health related feedback, the M group received coping skills training only, and the D group received discussion. Groups did not differ significantly in abstinence at each of the 11 weeks.

No description available.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24429号 / 理博第4928号 / 新制||理||1704(附属図書館) / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)准教授 三宅 亮, 教授 野口 高明, 教授 下林 典正 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

This thesis studies currency premia and their connections with macroeconomics. In the first essay, I link currency premia to capital-output ratios and the well-known “Lucas Paradox”. The “Lucas Paradox” states that there are large and persistent differences in capital-output ratios across countries, suggesting capital is not flowing to countries where it is relatively scarce. In the data, capital-output ratios vary a lot cross-sectionally even within developed countries, and they are negatively correlated with currency risk premia and risk-free rates. To rationalize these patterns, I build a quantitative multi-country model of capital accumulation with external habit and heterogeneous exposures to a global productivity shock. I show that currency risk in this model generates cross-country variations in risk-free rates and capital-output ratios that are consistent with the data. I estimate the model using GDP data from countries issuing the G10 currencies and find two main results: (1) The heterogenous loadings that I extract from GDP data alone are highly correlated with capital-output ratios; and (2) when I feed the estimated loadings into the model, model-generated capital-output ratios account for roughly 55% of the cross-country variation in the data. I conclude that variation in currency risk and therefore currency risk premia have significant effects on the real economy. In the second essay, I identify a quantitative puzzle when using canonical consumption-based asset pricing models to match currency premia under complete markets. Canonical long-run risk and habit models induce a strong, negative correlation between the variance and the mean of the log stochastic discount factor to address the well-known equity premium puzzle. When applied to an open economy with complete markets, this key feature requires that differences in currency returns should arise primarily from predictable appreciations, a requirement that is at odds with the data. We term this tension between a high equity premium, smooth risk-free rates, and largely unpredictable exchange rates the currency premium puzzle and argue it is the underlying reason why existing international asset pricing models have struggled to simultaneously match data on currency returns, equity returns, and risk-free rates. In the third essay, I show that perturbation methods lead to significant computational errors when used to solve international risk-sharing models with Epstein and Zin (1989) preferences. In particular, if countries feature different sizes, the simulating results violate law of iterated expectations. Even under symmetric setups, the errors along a typical simulation path are non-negligible. I conclude that perturbation-based solutions of EZ risk-sharing models should be used with caution.

Sustaining behaviour change is fundamental for the effective uptake of policies and practices aimed at improving individual and collective health, yet it can be very difficult for individuals to adhere to new desired health-related behaviours. A prospective solution is to focus on instilling these behaviours as a habit. Once instilled as a habit, behaviours are performed automatically given specific cues, and they relieve the cognitive stress of having to make a volitional decision towards performing the behaviour - making it more resistant to relapse. Several information systems (IS) are being proposed to help individual users instil target behaviours as habits so that they can be performed even when intentions shift. However, these systems tend to be designed in an ad hoc manner and, as a result, their effectiveness can vary substantially. To better guide the design of information systems that can support users in forming health-related behaviours as a habit, we define a subclass of systems called Habit Formation Support Systems (HFSS) and adopt the design science research approach to develop two artifacts: (1) a design-relevant theory explaining and predicting how IS-supported habit formation can be achieved called the Theory for the Formation of IS-Supported Habits (T-FISSH); and (2) a suite of design principles to guide the design of systems that can effectively support users in forming a desired health-related behaviour as a habit. We contend that habit theory and IS continuance theory can be used to anchor the development of the two artifacts. The T-FISSH was refined and validated using exploratory and confirmatory focus groups with academics and health behaviour change practitioners respectively. The design principles were refined with systems design and development professionals and validated through a reusability check that involved a design activity and reusability questionnaire. The theoretical contribution of the thesis lies in moving the habit formation knowledge base into the design realm through the development of a design-relevant explanatory/predictive theory. From a practical perspective, this research presents a suite of theory-anchored design principles that are intended to guide the design and development of systems that can support users in forming desired health-related behaviours as a habit.

Sedentary behavior has been among the major challenges facing employees working in offices subsequently failing to attain WHO recommendations on physical activity. Office employees are mostly at high risk of developing non-communicable diseases because most of their work is executed while sitting. This study aims to explore how employees have experienced the influence of physical activity on their job performance at work by using a qualitative research approach. Semi-structured interviews were conducted with nine employees working in the banking industry in Tanzania. A content analysis was used to analyze the collected data. The main findings of this study highlighted the need to create a workplace culture that encourages physical activity. Having regular movement in the office has promoted employees’ health and overall job performance. Furthermore, employees experienced challenges such as time constraints, and high job demands hindering them from participating in physical activity which needs to be addressed. Finally, workplace health promotion influenced their overall health and enhanced well-being. Through physical activity, they experienced improved cognitive functions and better health. Therefore, this study concludes that there should be increased support of physical activity in the workplace for the benefit of employees’ health leading to their job performance.