Türkarslan, Kutlu Kağan
A number of theoretical models have been proposed to understand and explain insomnia disorder and its etiology. The present thesis argued that intrusive visual imagery (IVI) in the pre-sleep period may lead to classical conditioning which evokes and perpetuates hyperarousal in chronic insomnia. In Study 1 (N = 651), Pre-sleep Arousal Scale (PSAS) and Intrusive Visual Imagery and Verbal Thoughts Questionnaires (IVIVTQ) were adapted to Turkish. Factor structures of the Turkish forms were tested with exploratory factor analysis and confirmatory factor analysis in split half samples. The validities (convergent, divergent, incremental, discriminant) and reliabilities (internal consistency and test-retest) of the Turkish forms were also assessed in a subsample (N = 556) and a separate third sample (N = 88). The results of Study 1 showed that the Turkish forms of PSAS and IVIVTQ had good validity and reliability features. In Study 2, a path model comprising the variables of intrusive visual imagery (IVI), intrusive verbal thoughts (IVT), visual imagery ability (VIA), pre-sleep arousal (PSA), and insomnia severity (IS) was tested with 168 of 1444 participants who met DSM-5 criteria for Insomnia Disorder. The results showed that IVI, but not IVT, significantly predicted PSA and PSA predicted IS. Furthermore, the indirect effects of IVI via PSA on IS was significant. Finally, the moderator role of VIA on the relationship between IVI and PSA was not significant. The results of the studies were discussed in the light of existing literature. Clinical implications and suggestions for the future studies were proposed.


The Relationship Between Illness Duration And Brain Morphometry in Schizophrenia: Heschl's Gyrus and Prefrontal Cortex Volumetry
KARABAY, NURİ; ÖNİZ, ADİLE; Gökçay, Didem; ALPTEKİN, KÖKSAL; Hugdahl, Kenneth; ÖZGÖREN, MURAT (2013-01-01)
Introduction: The relationship between brain morphology and illness duration has been observed as a biomarker in psychiatric and neurologic patients, especially in schizophrenia. In this study, we aimed to investigate the relationship between the volumes of two target regions [prefrontal cortex (PFC) and Heschl's gyrus (HG)] and illness duration in schizophrenia. Such measurements can have implications for then understanding of cognitive impairments in schizophrenia.
The temporal precedence of metacognition in the development of anxiety and depression symptoms in the context of life-stress: A prospective study
YILMAZ, ARZU AKMAN; Gençöz, Tülin; Wells, Adrian (2011-04-01)
According to the metacognitive theory of psychological disorder, metacognitions are vulnerability factors in predicting development of psychological symptoms. The present study investigated metacognitive factors and life stress in a prospective test of their proposed temporal precedence in the development of anxiety and depression symptoms. Participants were 172 students and adults recruited in Ankara and Bolu, Turkey. Two separate sets of hierarchical regression analyses were conducted. In these analyses, ...
The Effect of context luminance on contrast perception
Pamir, Zahide; Acartürk, Cengiz; Boyacı, Hüseyin; Department of Cognitive Sciences (2014)
The present study has employed psychophysics and functional magnetic resonance imaging (fMRI) methodologies. The aim of the study is to investigate the role of bottom-up and top-down processing of luminance in contrast perception. In particular, since it is thought that visual illusions occur as a result of top-down processing by means of visual context, the present study investigates how luminance in context affects contrast perception by using brightness illusion. In other words, the purpose of the study ...
The effect of arginine-428 mutation on modulation of activity of human liver flavin monooxygenase 3 (FMO3) by imipramine and chlorpromazine
Adalı, Orhan; Philpot, RM (1999-07-01)
This study was carried out to investigate the molecular basis for modulation of recombinant FMO3-catalyzed activity by the tricyclicantidepressants, imipramine and chlorpromazine. A mutant of human liver FMO3 (T428R) was formed by site-directed mutagenesis and characterized along with the native enzyme in order to elucidate a possible structure-function relationship. Functional properties of native and T428R human FMO3s were studied with methimazole as substrate. Both enzymes catalyzed the S-oxidation of me...
An Information Theoretic Approach to Classify Cognitive States Using fMRI
Onal, Itir; Ozay, Mete; Firat, Orhan; GİLLAM, İLKE; Yarman Vural, Fatoş Tunay (2013-11-13)
In this study, an information theoretic approach is proposed to model brain connectivity during a cognitive processing task, measured by functional Magnetic Resonance Imaging (fMRI). For this purpose, a local mesh of varying size is formed around each voxel. The arc weights of each mesh are estimated using a linear regression model by minimizing the squared error. Then, the optimal mesh size for each sample, that represents the information distribution in the brain, is estimated by minimizing various inform...
Citation Formats
K. K. Türkarslan, “THE ROLES OF INTRUSIVE VISUAL IMAGERY AND VISUAL IMAGERY ABILITY IN INSOMNIA DISORDER,” Ph.D. - Doctoral Program, Middle East Technical University, 2022.