Mathematical Modeling of Risk-Taking in Bipolar Disorder: Evidence of Reduced Behavioral Consistency, With Altered Loss Aversion Specific to Those With History of Substance Use Disorder

Bipolar disorder (BD) is associated with excessive pleasure-seeking risk-taking behaviors that often characterize its clinical presentation. However, the mechanisms of risk-taking behavior are not well-understood in BD. Recent data suggest prior substance use disorder (SUD) in BD may represent certain trait-level vulnerabilities for risky behavior. This study examined the mechanisms of risk-taking and the role of SUD in BD via mathematical modeling of behavior on the Balloon Analogue Risk Task (BART). Three groups—18 euthymic BD with prior SUD (BD+), 15 euthymic BD without prior SUD (BD–), and 33 healthy comparisons (HC)—completed the BART. We modeled behavior using four competing hierarchical Bayesian models, and model comparison results favored the Exponential-Weight Mean-Variance (EWMV) model, which encompasses and delineates five cognitive components of risk-taking: prior belief, learning rate, risk preference, loss aversion, and behavioral consistency. Both BD groups, regardless of SUD history, showed lower behavioral consistency than HC. BD+ exhibited more pessimistic prior beliefs (relative to BD– and HC) and reduced loss aversion (relative to HC) during risk-taking on the BART. Traditional measures of risk-taking on the BART (adjusted pumps, total points, total pops) detected no group differences. These findings suggest that reduced behavioral consistency is a crucial feature of risky decision-making in BD and that SUD history in BD may signal additional trait vulnerabilities for risky behavior even when mood symptoms and substance use are in remission. This study also underscores the value of using mathematical modeling to understand behavior in research on complex disorders like BD

Mathematical modeling of risk-taking in bipolar disorder: Evidence of reduced behavioral consistency, with altered loss aversion specific to those with history of substance use disorder

Supplement, code, and model diagnostics for the paper: Lasagna, C. A., Pleskac, T. J., Burton, C. Z., McInnis, M. G., Taylor, S. F., & Tso, I. F. (2022). Mathematical Modeling of Risk-Taking in Bipolar Disorder: Evidence of Reduced Behavioral Consistency, With Altered Loss Aversion Specific to Those With History of Substance Use Disorder. Computational Psychiatry, 6(1), 96–116. DOI: http://doi.org/10.5334/cpsy.6

Neural oscillations during gaze processing in bipolar disorder

Supplement, analysis codes, and analysis outputs for Lasagna et al. 2023 - "Reductions in regional theta power and fronto-parietal theta-gamma phase-amplitude coupling during gaze processing in bipolar disorder". Lasagna, C. A., Grove, T. B., Semple, E., Suzuki, T., Menkes, M. W., Pamidighantam, P., ... & Tso, I. F. (2023). Reductions in regional theta power and fronto-parietal theta-gamma phase-amplitude coupling during gaze processing in bipolar disorder. Psychiatry Research: Neuroimaging, 331, 111629

Reduced theta-band neural oscillatory activity during affective cognitive control in bipolar I disorder

Supplemental Materials for Preprint: Reduced theta-band neural oscillatory activity during affective cognitive control in bipolar I disorde

Social Cognition and Functional Connectivity in Schizophrenia and Early Psychosis

Individuals with schizophrenia (SZ) experience pervasive, treatment-resistant impairments in social cognition that contribute to poor functional outcomes. However, the mechanisms of social cognitive dysfunction in SZ remain poorly understood, which impedes the design of novel interventions to improve outcomes. This pre-registered project examines the representation of social functioning in the brain’s functional architecture across early psychosis (EP) and SZ. The study contains two parts: a confirmatory and an exploratory portion. In the confirmatory portion, we identified specific resting-state brain connectivity disruptions evident in EP and SZ. We performed a seed-based connectivity analysis using brain regions associated with social cognitive dysfunction in SZ (based on a published review) to test whether aberrant functional connectivity observed in SZ was also present in EP. In the exploratory portion, we assessed the out-of-sample generalizability and precision of resting state connectivity-based predictive models of social cognition. We used machine learning to predict social cognition from whole-brain connectomes and established the generalizability of these brain-behavior relationships with out-of-sample testing and cross-validation (to handle confounding variables). Results reveal significant decreases between the left inferior frontal gyrus and intraparietal sulcus that were evident in SZ but not EP. This connectivity profile is significantly associated with social cognition/functioning in both SZ and EP. Null predictive modeling results reveal the importance of out-of-sample evaluation, proper null hypothesis testing, and confound removal procedures. Overall, this work provides insights into the brain's functional architecture in SZ and EP. This work suggests that IFG-IPS connectivity profiles could be an important prognostic biomarker of social impairments and may be a target for future interventions focused on improved treatment outcomes related to social functioning

Deconstructing eye contact perception: Measuring perceptual precision and self-referential tendency using an online psychophysical eye contact detection task.

Eye contact perception-the ability to accurately and efficiently discriminate others' gaze directions-is critical to understanding others and functioning in a complex social world. Previous research shows that it is affected in multiple neuropsychiatric disorders accompanied by social dysfunction, and understanding the cognitive processes giving rise to eye contact perception would help advance mechanistic investigations of psychopathology. This study aims to validate an online, psychophysical eye contact detection task through which two constituent cognitive components of eye contact perception (perceptual precision and self-referential tendency) can be derived. Data collected from a large online sample showed excellent test-retest reliability for self-referential tendency and moderate reliability for perceptual precision. Convergence validity was supported by correlations with social cognitive measures tapping into different aspects of understanding others. Hierarchical regression analyses revealed that perceptual precision and self-referential tendency explained unique variance in social cognition, suggesting that they measure unique aspects of related constructs. Overall, this study provided support for the reliability and validity of the eye contact perception metrics derived using the online Eye Contact Detection Task. The value of the task for future psychopathology research was discussed

Social Cognition and Functional Connectivity in Schizophrenia and Early Psychosis

Individuals with schizophrenia (SZ) experience pervasive, treatment-resistant impairments in social cognition that contribute to poor functional outcomes. However, the mechanisms of social cognitive dysfunction in SZ remain poorly understood, which impedes the design of novel interventions to improve outcomes. This pre-registered project (https://doi.org/10.17605/OSF.IO/JH5FC) examines the representation of social functioning in the brain’s functional architecture across early psychosis (EP) and SZ. The study contains two parts: a confirmatory and an exploratory portion. In the confirmatory portion, we identified specific resting-state brain connectivity disruptions evident in EP and SZ. We performed a seed-based connectivity analysis using brain regions associated with social cognitive dysfunction in SZ (based on a published review) to test whether aberrant functional connectivity observed in SZ was also present in EP. In the exploratory portion, we assessed the out-of-sample generalizability and precision of resting state connectivity-based predictive models of social cognition. We used machine learning to predict social cognition from whole-brain connectomes and established the generalizability of these brain-behavior relationships with out-of-sample testing and cross-validation (to handle confounding variables). Results reveal significant decreases between the left inferior frontal gyrus and intraparietal sulcus that were evident in SZ but not EP. This connectivity profile is significantly associated with social cognition/functioning in both SZ and EP. Null predictive modeling results reveal the importance of out-of-sample evaluation, proper null hypothesis testing, and confound removal procedures. Overall, this work provides insights into the brain's functional architecture in SZ and EP. This work suggests that IFG-IPS connectivity profiles could be an important prognostic biomarker of social impairments and may be a target for future interventions focused on improved treatment outcomes related to social functioning

Mathematical modeling of risk-taking in bipolar disorder: Evidence of reduced behavioral consistency, with altered loss aversion specific to those with history of substance use disorder

Bipolar disorder (BD) is associated with excessive pleasure-seeking risk-taking behaviors that often characterize its clinical presentation. However, the mechanisms of risk-taking behavior are not well-understood in BD. Recent data suggest prior substance use disorder (SUD) in BD may represent certain trait-level vulnerabilities for risky behavior. This study examined the mechanisms of risk-taking and the role of SUD in BD via mathematical modeling of behavior on the Balloon Analogue Risk Task (BART). Three groups—18 euthymic BD with prior SUD (BD+), 15 euthymic BD without prior SUD (BD-), and 33 healthy comparisons (HC)—completed the BART. We modeled behavior using 4 competing hierarchical Bayesian models, and model comparison results favored the Exponential-Weight Mean-Variance (EWMV) model, which encompasses and delineates five cognitive components of risk-taking: prior belief, learning rate, risk preference, loss aversion, and behavioral consistency. Both BD groups, regardless of SUD history, showed lower behavioral consistency than HC. BD+ exhibited more pessimistic prior beliefs (relative to BD- and HC) and reduced loss aversion (relative to HC) during risk-taking on the BART. Traditional measures of risk-taking on the BART (adjusted pumps, total points, total pops) detected no group differences. These findings suggest that reduced behavioral consistency is a crucial feature of risky decision-making in BD and that SUD history in BD may signal additional trait vulnerabilities for risky behavior even when mood symptoms and substance use are in remission. This study also underscores the value of using mathematical modeling to understand behavior in research on complex disorders like BD

Continuous theta burst stimulation to the secondary visual cortex does not impair central vision in humans during a simple detection task

Supplemental analysis code to accompany article

Structural connectivity of an interoception network in schizophrenia

Interoception refers to the processing, integration, and interpretation of bodily signals by the brain. Interoception is key to not only basic survival, but also many cognitive processes, especially motivational and affective functioning. There is emerging evidence suggesting altered interoception in schizophrenia, but few studies have explored their potential neural underpinning. The current study aims to investigate the anatomical connectivity of a previously identified interoception network in individuals with schizophrenia, and the relationship between structural connectivity in this network and both emotional functioning and clinical symptoms. Thirty-five participants with schizophrenia (SZ) and 36 healthy control participants (HC) underwent diffusion tensor imaging (DTI) and performed tasks measuring emotional functioning. Probabilistic tractography was used to identify white matter tracts connecting key hubs in an interoception network (rostral and caudal anterior cingulate cortex, ventral anterior insula, dorsal mid and posterior insula, and amygdala). Microstructural integrity of these tracts was compared across groups and correlated with measures of emotional functioning and symptom severity. Compared with HC, SZ exhibited altered structural connectivity in the interoception network, specifically between the amygdala and the insular cortex. In HC, the structural connectivity of the network was significantly correlated with emotion recognition, supporting a link between the interoception network and emotional functioning. However, this correlation was much weaker in SZ, suggesting less involvement of this network. These findings suggest that altered interoception may have implications for illness mechanisms of schizophrenia, especially in relation to emotional deficits