Psychometric, Cognitive, and Oculomotor Characteristics of Schizotypy and Schizophrenia Spectrum Disorders

Schizophrenia spectrum disorders are considered to be among the most severe mental health issues. However, the question of their etiological mechanisms is still unsolved and requires further research. One promising approach in this context is the study of schizotypy, defined as a temporally stable set of personality traits that mimic symptoms of schizophrenia in an attenuated, subclinical form. Comparing schizotypy to the full-blown clinical disorder can help identify etiological mechanisms, including both risk and protective factors. In this thesis, I provide a detailed overview of schizotypy, including its psychometric characteristics, introduce cognitive and oculomotor continuities between schizophrenia spectrum disorders and schizotypy, and summarize discontinuities suggesting the operation of protective mechanisms in schizotypy. Subsequently, I present four original studies that build upon previous findings and fill relevant gaps left by prior research: In a psychometric study, network analysis was applied to resolve previously reported inconsistencies in one of the most widely used schizotypy questionnaires. In a behavioral investigation, I examined how schizotypy was related to cognitive functions and whether this was affected by experimentally induced sleep deprivation, a manipulation that is considered to evoke transient schizophrenia-like behaviors and experiences. In two studies combining eye tracking with psychophysical approaches, functional magnetic resonance imaging, and machine learning, I examined the cognitive, perceptual, and neural mechanisms of altered smooth pursuit eye movements (an oculomotor marker of schizophrenia) in schizotypal individuals and schizophrenia spectrum patients. Together, the studies of the present thesis indicate that similarities between schizotypy and schizophrenia spectrum disorders are selective and may be found in basic, specific sub-components of complex, high level functions rather than in the complex functions themselves. This interpretation corroborates the hypothesis that protective mechanisms operate in schizotypal individuals, suggesting that such mechanisms prevent schizotypes from displaying the full phenotype of schizophrenia spectrum disorders. Additionally, embedding the original studies presented in this thesis into previously published research, it appears that different schizophrenia like characteristics might develop in a highly differentiated fashion along a continuum from low to high levels of schizotypy. Accordingly, more advanced expressions of schizotypy might be associated with a wider range of schizophrenia-like characteristics compared to less intense expressions

Impact of insect herbivory on plant stress volatile emissions from trees : A synthesis of quantitative measurements and recommendations for future research

Plants, and particularly trees, are the largest source of atmospheric volatile organic compounds globally. Insect herbivory alters plant volatile emission rates and the types of compounds that are emitted. These stress volatiles are a major contribution to total plant volatile emissions during active herbivore feeding, with important implications for atmospheric chemistry processes. However, emission models do not currently have a quantitative description of plant volatile emission rates during and after insect herbivore feeding. This review provides a brief background on plant volatile organic compounds, the urgency of including biotic stress emissions in models, and a summary of plant volatile emission models and steps they have taken to incorporate stress emissions into their framework. The review ends with a synthesis of volatile emissions from trees during insect herbivory. This synthesis highlights key gaps in studied systems and measurement approaches. We provide a summary of recommendations for future work to address these gaps, improve comparability between studies, and generate the data-sets we need to develop a descriptive model of these plant stress volatile emissions.Peer reviewe

Extreme mediation: Observing mental and physical health in everyday life

The excessive use of smartphones resulting in extreme mediation has been identified to result in psychological problems including anxiety, depression, and an overall neural change that is impacting people of all ages on many levels. An exploratory study using Experience Sampling Method (ESM) concluded a significant increase in positive mood, conscious awareness of the surrounding environment, and an increased number of participants self-reporting physical activity lasting 15 minutes on days without smartphone use. Results suggest the need to avoid increased use of noninvasive technology such as smartphones resulting in deterioration of mental and physical health

Consumer Health Informatics: Empowering Healthy-Lifestyle-Seekers Through mHealth

People are at risk from noncommunicable diseases (NCD) and poor health habits, with interventions like medications and surgery carrying further risk of adverse effects. This paper addresses ways people are increasingly moving to healthy living medicine (HLM) to mitigate such health threats. HLM-seekers increasingly leverage mobile technologies that enable control of personal health information, collaboration with clinicians/other agents to establish healthy living practices. For example, outcomes from consumer health informatics research include empowering users to take charge of their health through active participation in decision-making about healthcare delivery. Because the success of health technology depends on its alignment/integration with a person's sociotechnical system, we introduce SEIPS 2.0 as a useful conceptual model and analytic tool. SEIPS 2.0 approaches human work (i.e., life's effortful activities) within the complexity of the design and implementation of mHealth technologies and their potential to emerge as consumer-facing NLM products that support NCDs like diabetes

The Influence of Holistic and Analytic Cognitive Styles on Online Information Design: Toward a communication theory of cultural cognitive design

Although studies have linked culture to online user preferences and performance, few communication researchers have recognized the impact of culture on online information design and usability. It is important to ask if people are better able to use and prefer Web sites created by designers from their own culture. We propose that to improve computer-mediated communication, Web site design should accommodate culturally diverse user groups. First, a body of research is presented that aligns East Asian cultures with more holistic cognitive styles and Western cultures with more analytical cognitive styles. Building on this contrast, a theory of cultural cognitive design is proposed as a means of understanding how cognitive styles that develop under the influence of culture lead to different ways of designing and organizing information for the Web