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Publication Metadata only A Bayesian network analysis to examine the effects of HIV stigma processes on self-concept and depressive symptoms among persons living with HIV(Wiley, 2024) Pala, Andrea Norcini; Department of Psychology; Turan, Bülent; Department of Psychology; College of Social Sciences and HumanitiesObjective: This study examines the relationships between HIV stigma dimensions, self-related mechanisms, and depressive symptoms among persons living with HIV. Background: HIV stigma hinders the well-being of individuals living with HIV, which is linked to depressive symptoms and increased risk of poor clinical outcomes. However, the mechanisms underlying stigma's impact on depression are poorly understood. Psychosocial theories propose that experiencing HIV stigma leads to internalized stigma, impacting self-concept and mental health. Method: Using Bayesian network analysis, we explored associations among HIV stigma processes (experienced, anticipated, internalized, perceived community stigma, and HIV status disclosure) and self-related mechanisms (self-esteem, fear of negative evaluation [FNE], self-blame coping, and social exclusion), and depressive symptoms. Results: Our diverse sample of 204 individuals, primarily men, gay/bisexual, Black, and lower-middle SES, who experienced stigma showed increased anticipated, internalized, and perceived community stigma, FNE, and depressive symptoms. Internalized stigma contributed to self-blame coping and higher depressive symptoms. Anticipated and perceived community stigma and FNE correlated with increased social exclusion. Discussion: This study investigates potential mechanisms through which HIV stigma may impact depression. Identifying these mechanisms establishes a foundation for future research to inform targeted interventions, enhancing mental health and HIV outcomes among individuals living with HIV, especially from minority backgrounds. Insights gained guide evidence-based interventions to mitigate HIV stigma's detrimental effects, ultimately improving overall well-being and health-related outcomes for people with HIV.Publication Metadata only A simple three layer excitatory-inhibitory neuronal network for temporal decision-making(Elsevier, 2020) Zeki, Mustafa; Department of Psychology; Balcı, Fuat; Faculty Member; Department of Psychology; College of Social Sciences and Humanities; 51269Humans and animals do not only keep track of time intervals but they can also make decisions about durations. Temporal bisection is a psychophysical task that is widely used to assess the latter ability via categorization of durations as short or long. Many existing models of performance in temporal bisection primarily account for choice proportions and tend to overlook the associated response times. We propose a time-cell neural network that implements both interval timing and temporal categorization. The proposed model can keep track of time intervals based on lurching wave activity, it can learn the reference durations along with their association with different categorization responses, and finally, it can carry out the comparison of arbitrary intermediate durations to the reference durations. We compared the model's predictions about choice behavior and response times to the empirical data previously gathered from rats. We showed that this time-cell neural network can predict the canonical behavioral signatures of temporal bisection performance. Specifically, (a) the proposed model can account for the sigmoidal relationship between the probability of the long choices and the test durations, (b) the superposition of choice functions on a relative time scale, (c) the localization of the point of subjective equality at the geometric mean of the reference durations, and (d) the differential modulation of short and long categorization response times as a function of the test durations.Publication Open Access A simplified model of communication between time cells: accounting for the linearly increasing timing imprecision(Frontiers, 2019) Department of Psychology; Balcı, Fuat; Faculty Member; Department of Psychology; College of Social Sciences and Humanities; 51269Many organisms can time intervals flexibly on average with high accuracy but substantial variability between the trials. One of the core psychophysical features of interval timing functions relates to the signatures of this timing variability; for a given individual, the standard deviation of timed responses/time estimates is nearly proportional to their central tendency (scalar property). Many studies have aimed at elucidating the neural basis of interval timing based on the neurocomputational principles in a fashion that would explain the scalar property. Recent experimental evidence shows that there is indeed a specialized neural system for timekeeping. This system, referred to as the “time cells,” is composed of a group of neurons that fire sequentially as a function of elapsed time. Importantly, the time interval between consecutively firing time cell ensembles has been shown to increase with more elapsed time. However, when the subjective time is calculated by adding the distributions of time intervals between these sequentially firing time cell ensembles, the standard deviation would be compressed by the square root function. In light of this information the question becomes, “How should the signaling between the sequentially firing time cell ensembles be for the resulting variability to increase linearly with time as required by the scalar property?” We developed a simplified model of time cells that offers a mechanism for the synaptic communication of the sequentially firing neurons to address this ubiquitous property of interval timing. The model is composed of a single layer of time cells formulated in the form of integrate-and-fire neurons with feed-forward excitatory connections. The resulting behavior is simple neural wave activity. When this model is simulated with noisy conductances, the standard deviation of the time cell spike times increases proportionally to the mean of the spike-times. We demonstrate that this statistical property of the model outcomes is robustly observed even when the values of the key model parameters are varied.Publication Metadata only A sniff of happiness(Sage, 2015) de Groot, Jasper H. B.; Smeets, Monique A. M.; Rowson, Matt J.; Bulsing, Patricia J.; Blonk, Cor G.; Wilkinson, Joy E.; Department of Psychology; Semin, Gün Refik; Researcher; Department of Psychology; College of Social Sciences and Humanities; N/AIt is well known that feelings of happiness transfer between individuals through mimicry induced by vision and hearing. The evidence is inconclusive, however, as to whether happiness can be communicated through the sense of smell via chemosignals. As chemosignals are a known medium for transferring negative emotions from a sender to a receiver, we examined whether chemosignals are also involved in the transmission of positive emotions. Positive emotions are important for overall well-being and yet relatively neglected in research on chemosignaling, arguably because of the stronger survival benefits linked with negative emotions. We observed that exposure to body odor collected from senders of chemosignals in a happy state induced a facial expression and perceptual-processing style indicative of happiness in the receivers of those signals. Our findings suggest that not only negative affect but also a positive state (happiness) can be transferred by means of odors.Publication Metadata only A systematic review and meta-analysis of social cognition among people living with HIV;implications for non-social cognition and social everyday functioning(Springer, 2024) Vance, David E.; Billings, Rebecca; Lambert, Crystal Chapman; Fazeli, Pariya L.; Goodin, Burel R.; Kempf, Mirjam-Colette; Rubin, Leah H.; Wise, Jenni; Hellemann, Gerhard; Lee, Junghee; Department of Psychology; Turan, Bülent; Department of Psychology; ; College of Social Sciences and Humanities;Social cognition-the complex mental ability to perceive social stimuli and negotiate the social environment-has emerged as an important cognitive ability needed for social functioning, everyday functioning, and quality of life. Deficits in social cognition have been well documented in those with severe mental illness including schizophrenia and depression, those along the autism spectrum, and those with other brain disorders where such deficits profoundly impact everyday life. Moreover, subtle deficits in social cognition have been observed in other clinical populations, especially those that may have compromised non-social cognition (i.e., fluid intelligence such as memory). Among people living with HIV (PLHIV), 44% experience cognitive impairment; likewise, social cognitive deficits in theory of mind, prosody, empathy, and emotional face recognition/perception are gradually being recognized. This systematic review and meta-analysis aim to summarize the current knowledge of social cognitive ability among PLHIV, identified by 14 studies focused on social cognition among PLHIV, and provides an objective consensus of the findings. In general, the literature suggests that PLHIV may be at-risk of developing subtle social cognitive deficits that may impact their everyday social functioning and quality of life. The causes of such social cognitive deficits remain unclear, but perhaps develop due to (1) HIV-related sequelae that are damaging the same neurological systems in which social cognition and non-social cognition are processed; (2) stress related to coping with HIV disease itself that overwhelms one's social cognitive resources; or (3) may have been present pre-morbidly, possibly contributing to an HIV infection. From this, a theoretical framework is proposed highlighting the relationships between social cognition, non-social cognition, and social everyday functioning.Publication Metadata only A universal cue for grammatical categories in the input to children: frequent frames(Elsevier Science Bv, 2018) Moran, Steven; Blasi, Damian E.; Schikowski, Robert; Pfeiler, Barbara; Allen, Shanley; Stoll, Sabine; Department of Psychology; Küntay, Aylin C.; Faculty Member; Department of Psychology; College of Social Sciences and Humanities; 178879How does a child map words to grammatical categories when words are not overtly marked either lexically or prosodically? Recent language acquisition theories have proposed that distributional information encoded in sequences of words or morphemes might play a central role in forming grammatical classes. To test this proposal, we analyze child-directed speech from seven typologically diverse languages to simulate maximum variation in the structures of the world's languages. We ask whether the input to children contains cues for assigning syntactic categories in frequent frames, which are frequently occurring nonadjacent sequences of words or morphemes. In accord with aggregated results from previous studies on individual languages, we find that frequent word frames do not provide a robust distributional pattern for accurately predicting grammatical categories. However, our results show that frames are extremely accurate cues cross-linguistically at the morpheme level. We theorize that the nonadjacent dependency pattern captured by frequent frames is a universal anchor point for learners on the morphological level to detect and categorize grammatical categories. Whether frames also play a role on higher linguistic levels such as words is determined by grammatical features of the individual language.Publication Metadata only Abnormal high-energy phosphate molecule metabolism during regional brain activation in patients with bipolar disorder(Nature Publishing Group (NPG), 2015) Yuksel, C.; Du, F.; Ravichandran, C.; Goldbach, J. R.; Thida, T.; Lin, P.; Gelda, J.; O'Connor, L.; Sehovic, S.; Gruber, S.; Ongur, D.; Cohen, B. M.; Department of Psychology; Dora, Begüm; PhD Student; Department of Psychology; College of Social Sciences and Humanities; N/AConverging evidence suggests bioenergetic abnormalities in bipolar disorder (BD). In the brain, phosphocreatine (PCr) acts a reservoir of high-energy phosphate (HEP) bonds, and creatine kinases (CK) catalyze the transfer of HEP from adenosine triphosphate (ATP) to PCr and from PCr back to ATP, at times of increased need. This study examined the activity of this mechanism in BD by measuring the levels of HEP molecules during a stimulus paradigm that increased local energy demand. Twenty-three patients diagnosed with BD-I and 22 healthy controls (HC) were included. Levels of phosphorus metabolites were measured at baseline and during visual stimulation in the occipital lobe using P-31 magnetic resonance spectroscopy at 4T. Changes in metabolite levels showed different patterns between the groups. During stimulation, HC had significant reductions in PCr but not in ATP, as expected. In contrast, BD patients had significant reductions in ATP but not in PCr. In addition, PCr/ATP ratio was lower at baseline in patients, and there was a higher change in this measure during stimulation. This pattern suggests a disease-related failure to replenish ATP from PCr through CK enzyme catalysis during tissue activation. Further studies measuring the CK flux in BD are required to confirm and extend this finding.Publication Metadata only Addressing the mental health needs of those affected by the earthquakes in Türkiye(Elsevier, 2023) Kurt, Gülşah; Uygun, Ersin; Aker, A Tamer; Department of Psychology; Acartürk, Ceren; Faculty Member; Department of Psychology; College of Social Sciences and Humanities; 39271N/APublication Metadata only Adolescence amid a pandemic: short- and long-term implications(Wiley, 2021) Hussong, Andrea M.; Benner, Aprile D.; Lansford, Jennifer E.; Makila, Leunita Makutsa; Petrie, Rachel C.; Department of Psychology; Faculty Member; Department of Psychology; College of Social Sciences and Humanities; 222027Members of the Society for Research on Adolescents COVID-19 Response Team offer this commentary to accompany this special issue of the Journal of Research on Adolescence regarding the impact of the pandemic on adolescents' social, emotional, and academic functioning. In addition to outlining the critical need for scholarly collaboration to address the global impact of this crisis on adolescent development, we argue that a broad investigative lens is needed to guide research and recovery efforts targeting youth development. We then use this broad lens to consider dimensions of the pandemic impact relative to developmental implications within community and policy contexts, educational contexts, social contexts, and family contexts. Finally, we describe guideposts for setting a global, shared research agenda that can hasten research to recovery efforts surrounding the pandemic and youth development.Publication Open Access Adverse childhood experiences and global mental health: avenues to reduce the burden of child and adolescent mental disorders(Cambridge University Press (CUP), 2022) Ceccarelli, C.; Prina, E.; Muneghina, O.; Jordans, M.; Barker, E.; Miller, K.; Singh, R.; Sorsdhal, K.; Cuijpers, P.; Lund, C.; Barbui, C.; Purgato, M.; Department of Psychology; Acartürk, Ceren; Faculty Member; Department of Psychology; College of Social Sciences and Humanities; 39271Mental disorders are one of the largest contributors to the burden of disease globally, this holds also for children and adolescents, especially in low-and middle-income countries. The prevalence and severity of these disorders are influenced by social determinants, including exposure to adversity. When occurring early in life, these latter events are referred to as adverse childhood experiences (ACEs). In this editorial, we provide an overview of the literature on the role of ACEs as social determinants of mental health through the lenses of global mental health. While the relation between ACEs and mental health has been extensively explored, most research was centred in higher income contexts. We argue that findings from the realm of global mental health should be integrated into that of ACEs, e.g. through preventative and responsive psychosocial interventions for children, adolescents and their caregivers. The field of global mental health should also undertake active efforts to better address ACEs in its initiatives, all with the goal of reducing the burden of mental disorders among children and adolescents globally.