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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/3

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Department: search.filters.department.Department of PsychologySubject: search.filters.subject.Clinical neurology

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Now showing 1 - 5 of 5
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    Etanercept rescues cognitive deficits, depression-like symptoms, and spike-wave discharge incidence in WAG/Rij rat model of absence epilepsy
    (Elsevier, 2021) Karson, Ayşe; Utkan, Tijen; Şahin, Tuğçe Demirtaş; Arkan, Sertan; Ateş, Nurbay; Department of Psychology; Balcı, Fuat; Faculty Member; Department of Psychology; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); College of Social Sciences and Humanities; 51269
    Pro-inflammatory cytokines have been shown to be associated with the development of seizures in the WAG/Rij rat model of absence epilepsy. Importantly, WAG/Rij rats also exhibit cognitive deficits and depression-like behaviors. It is possible that pro-inflammatory cytokines mediate these comorbid conditions of absence epilepsy given their well-established effects on cognition and affective responses. The current study investigated the potential therapeutic effect of etanercept (tumor necrosis factor inhibitor) on cognitive impairment, depression-like behavior, and spike-wave discharges (SWDs) typically observed in the WAG/Rij rats. Eight-month-old male WAG/Rij rats and Wistar controls were tested in Morris water maze (MWM), passive avoidance (PA), forced swimming, sucrose preference, and locomotor activity tests, and electroencephalogram (EEG) recordings were taken from a separate group of WAG/Rij rats after 8 weeks of etanercept or vehicle treatment. Consistent with earlier work, WAG/Rij rats exhibited cognitive deficits and depression-like behavior. From these, the cognitive deficits and despair-like behavior were rescued by etanercept administration, which also reduced the frequency of SWDs without affecting their duration. Our results support the hypothesis that pro-inflammatory cytokines mediate the absence seizures and comorbid symptoms of absence epilepsy.
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    Infliximab rescues cognitive impairment induced by unpredictable chronic mild stress in a rat model of depression
    (Elsevier, 2014) Demirtaş, Tuna; Utkan, Tijen; Yazir, Yusufhan; Karson, Ayşe; Bayramgürler, Dilek; Department of Psychology; Balcı, Fuat; Faculty Member; Department of Psychology; College of Social Sciences and Humanities; 51269
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    Do neoliberal values provide a fertile soil for suicidal ideation?
    (Elsevier, 2022) Department of Psychology; Department of Psychology; Eskin, Mehmet; Baydar, Nazlı; Faculty Member; Faculty Member; Department of Psychology; College of Social Sciences and Humanities; College of Social Sciences and Humanities; 2210; 50769
    Background: Values associated with neoliberal ideologies are blamed for damaging the social fabric. They may also have deleterious effects on suicidal ideation.Objective: We investigated whether neoliberal values were associated with the risk for suicidal ideation through a set of mediating factors (suicide stigma, help-seeking attitudes, perceived stress, and suicide acceptability).Methods: A total of 508 (249 female) adults from the U.S. responded to a self-administered questionnaire that contained measures of suicidal ideation, neoliberal values, suicide stigma, help-seeking attitudes, perceived stress, and suicide acceptability. We tested a path model that linked neoliberal values to suicidal ideation through multiple mediators. We tested total versus partial mediation models. Results: We found empirical evidence for a full mediation of the association of neoliberal values with perceived stress. Neoliberal values were associated with suicide stigma; suicide stigma was associated with negative atti-tudes towards help-seeking, which, in turn, were associated with high levels of perceived stress. The association of neoliberal values with suicide acceptability was partially mediated. Perceived stress was positively associated with suicide risk directly and indirectly through suicide acceptability. Conclusion: Our findings suggest that values related to neoliberal ideologies prepare a context that fosters the risk for suicide. For a contextualized understanding of suicidal behavior, more research is needed that explores the role of social, cultural, political, and economic ideologies in the suicidal process.
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    Obsessive-compulsive tendencies and action sequence complexity: an information theory analysis
    (Springer, 2019) Zeki, Mustafa; Moustafa, Ahmed A.; Department of Psychology; Department of Psychology; Balcı, Fuat; Öztel, Tutku; Faculty Member; Teaching Faculty; Department of Psychology; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); College of Social Sciences and Humanities; College of Social Sciences and Humanities; 51269; N/A
    Obsessive-compulsive disorder (OCD) is a psychiatric condition that is primarily associated with anxiety provoking repetitive thoughts (i.e., obsessions) and actions that are manifested to neutralize the resultant anxiety (i.e., compulsions). Interestingly, OCD patients continue compulsive behaviors (e.g., repeatedly rechecking if the door is locked) although they are typically aware of the irrationality of these behaviors. This suggests that compulsive behaviors have habit-like features. We predicted that the motor actions (e.g., sequence of goalless key presses) would deviate from randomness in individuals with stronger obsessive-compulsive (OC) tendencies and thus expected to observe more rigid sequential action patterns in these individuals (e.g., pressing keys according to a motif). We applied entropy theory approach, defined as the rate of change of information in a given sequence, to test this hypothesis. We collected two different types of sequential behavioral data from healthy individuals and scored their obsessive-compulsive tendencies based on the Padua Inventory. In the first method, we asked participants to press one of the two buttons sequentially. In the second method, participants were asked to mark one of the four different options sequentially (on a multiple-choice optic form). The behavioral characterization was carried out by quantifying the entropy in the sequence of two sets of behavioral data using the Shannon metric entropy and Lempel-Ziv complexity measures. Our results revealed a negative relationship between the degree of washing tendencies and the level of information contained in action sequences. These results held only for the data collected with key presses and not for the choice sequences in the paper-pencil task. Based on these results, we conclude that the behavioral rigidity observed in the form of compulsive actions may generalize to some other behaviors of the individual.
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    Integrity and function of gestures in aphasia
    (Taylor & Francis, 2018) Nozari, Nazbanou; N/A; Department of Psychology; Akhavan, Niloofar; Göksun, Tilbe; Master Student; Faculty Member; Department of Psychology; Graduate School of Social Sciences and Humanities; College of Social Sciences and Humanities; N/A; 47278
    Background: Gestures can provide an excellent natural alternative to verbal communication in people with aphasia (PWA). However, despite numerous studies focusing on gesture production in aphasia, it is still a matter of debate whether the gesture system remains intact after language impairment and how PWA use gestures to improve communication. A likely source for the contradicting results is that many studies were conducted on individual cases or in heterogeneous groups of individuals with additional cognitive deficits such as conceptual impairment and comorbid conditions such as limb apraxia.Aims: The goal of the current study was to evaluate the integrity and function of gestures in PWA in light of cognitive theories of language-gesture relationship. Since all such theories presuppose the integrity of the conceptual system, and the absence of comorbid conditions that selectively impair gesturing (i.e., limb apraxia), our sample was selected to fulfill these assumptions.Methods & Procedures: We examined gesture production in eight PWA with preserved auditory comprehension, no comorbidities, and various degrees of expressive deficit, as well as 11 age- and education-matched controls, while they described events in 20 normed video clips. Both speech and gesture data were coded for quantitative measures of informativeness, and gestures were grouped into several functional categories (matching, complementary, compensatory, social cueing, and facilitating lexical retrieval) based on correspondence to the accompanying speech. Using rigorous group analyses, individual-case analyses, and analyses of individual differences, we provide converging evidence for the integrity and type of function(s) served by gesturing in PWA.Outcomes & Results: Our results indicate that the gesture system can remain functional even when language production is severely impaired. Our PWA heavily relied on iconic gestures to compensate for their language impairment, and the degree of such compensation was correlated with the extent of language impairment. In addition, we found evidence that producing iconic gestures was related to higher success rates in resolving lexical retrieval difficulties.Conclusions: When comprehension and comorbidities are controlled for, impairment of language and gesture systems is dissociable. In PWA with good comprehension, gesturing can provide an excellent means to both compensate for the impaired language and act as a retrieval cue. Implications for cognitive theories of language-gesture relationship and therapy are discussed.