preprints
I make an effort to post my research early as a preprint whenever possible. Feel free to leave peer commentary on any of the preprints below or to email me with suggestions. They are all works in progress!
2024
This study explored the causes and interactions of psychosis proneness (PP) in nonclinical populations, employing causal discovery analysis (CDA) on data from 194 healthy adolescent and young adult twins and siblings in Türkiye. Assessments covered various factors including sociodemographic status, environmental risks, and brain function. The findings revealed that negative self-schema has the largest effect on PP, while social cohesion and trust offer protection against it. Additionally, PP leads to increased activity in the DLPFC region of the brain. These insights, marking a first in data-driven causal modeling of PP, underscore the importance of targeting negative self-schema and enhancing social cohesion for preventive interventions.
2023
We used hierarchical Drift Diffusion Modeling (hDDM) to analyze proactive and reactive control deficits in individuals with schizophrenia and other psychotic disorders. Comparing people with psychosis (PwP), their first-degree relatives, and controls using the Dot Pattern Expectancy task, we found that PwP exhibited slower proactive control and perceptual processing. Machine learning analysis showed hDDM parameters effectively distinguished between these groups, highlighting specific deficits in motor/perceptual time and evidence integration, especially in proactive control.
We investigate the neural connections between PTSD symptoms and heavy drinking in veterans. Using EEG, we found that PTSD is linked to heightened mediofrontal theta responses to losses, indicating increased sensitivity to negative prediction errors. In contrast, heavy drinking corresponds to reduced theta responses, suggesting a dampening effect on these errors. The findings highlight a shared neural basis in PTSD and alcohol use, with implications for treatment strategies.
Sunday Francis, Angela Tseng, Eric Rawls, Christine Conelea, Nicola Grissom, Eric Kummerfeld, Sisi Ma, Suma Jacob
We address sex-based discrepancies in autism spectrum disorder (ASD) diagnoses using a network-theory-based approach on data from the Simons Simplex Collection. Analyzing 2175 autistic males and 334 autistic females, the study used exploratory factor analysis and expert clinical review to focus on 15 key factors. To counter sample imbalances, a subset of males was matched with females based on age and IQ. Causal Discovery Analysis revealed sex-specific directional relationships in autism phenotypes across sensory, social, and behavior domains, providing insights for developmental outcomes and targeted interventions.
The NeuroFreq toolbox for MATLAB, introduced in this paper, enhances the analysis of M/EEG data through consistent implementation of multiple time-frequency (TF) transformation algorithms. It addresses the inconsistencies in current toolboxes by offering comprehensive features for linear and quadratic TF decomposition, along with utilities for resampling, averaging, baseline correction, and visualization across multiple channels. This toolbox simplifies TF analysis for newcomers and facilitates community comparison of various TF methods, demonstrated through applications to both synthetic and EEG data.
2022
This study on PTSD in U.S. military veterans finds that somatomotor beta bursts (BBR) rates, observed during a cognitive control task, correlate with response direction and conflict monitoring. Increased BBRs are associated with greater posttraumatic stress symptoms and mediate the link between these symptoms and decreased conflict monitoring accuracy. The results suggest that cognitive control deficits in PTSD are due to a failure in adaptively disinhibiting target motor representations, indicating BBR as a potential marker for cognitive control assessment in various brain disorders.