Isaac Fradkin

(8/8) We hope this work helps bridge NLP in psychiatry and theory-driven computational modeling by highlighting the potential use of simulations to enhance understanding.

A huge thanks to @schizbulletin.bsky.social, the editor, and the insightful reviewers for their pivotal input.

(7/8) These new 'semantic density metrics' were also better at detecting repetitiveness in a reanalysis of a previous dataset, particularly for psychopathological dimensions corresponding with depressive and internalizing symptoms more generally. An interesting finding for future work!

(6/8)
Findings: Cosine distance metrics were suboptimal in detecting simulated perseveration. They were outperformed by new semantic density metrics using dimensionality reduction to examine (roughly speaking) if a smaller number of sentences could have conveyed the same message.

(5/8)
To tackle this, we used generative language modeling to simulate texts characterized by derailment, repetitiveness, or both, and tested whether different NLP metrics could accurately capture these manipulations.

(4/8)
This leads to the key questions: Should we predict larger or smaller cosine distances in psychosis? What happens when derailment and repetitiveness in language co-occur?

(3/8)
But here’s a conundrum: Early findings correlated psychosis with greater cosine distances between utterances, yet recent studies found the opposite. Reduced distances may reflect repetitive language, common in psychosis, but also in other conditions, like depression🤷‍♂️

(2/8)
With the rise of Language Models, NLP in psychiatry is rapidly growing. Cosine distance metrics, for instance, are widely used to capture derailment and other forms of incoherence in conditions like psychosis.

Characterizing the Paradoxical Interplay of Semantic Perseveration and Derailment in Psychiatry Using Theory-Driven Generative Language Simulations AbstractBackground and Hypothesis. Formal thought disorder (FTD), characterized by derailment and perseveration, is a central feature in psychosis and can

(1/8)
So proud to share our new paper, led by the brilliant Robin Qullivic, aiming to improve the theoretical & psychometric transparency of #NLP in #Psychiatry, focusing on metrics for language repetitiveness.
Preprint: hal.science/hal-05086512/
Full paper: doi.org/10.1093/schb...

🚀 We are hiring! 🚀

🔍 Join us as a Postdoctoral Researcher (fully-funded) at the Helmholtz Institute for Human-Centered AI in Munich.

A Letter by Israeli Social Psychologists Dear friends of the Social Psychology community, After October 7, a group of Israeli social psychologists, including many of us, wrote a letter expressing our deep shock at the massacre, abuse, rape,...

Hesitant to step outside science here, yet I must share this letter:
docs.google.com/document/d/1...
A group of Israeli psychology faculty speak out clearly against the government's decisions and the resulting devastation in Gaza and the risk to hostages.

In hopes of peace and safety for all.

What an awesome #CPConf2025! If you're interested in funded PhD or PostDoc opportunities (remote possible) do reach out (Paul.sharp@biu.ac.il).

we have exciting new paradigms modelling planning, meta- control, offline learning, and their relation to psychopathology.

See: Sharplabbiu.github.io

If you are coming to #CPConf2025, come say hello! Also, please check out the cool🆕work from our Thought Dynamics Lab! 💭

Semantic cognition, Ostracism, Theory-driven Generative Language Modeling, Perseverative speech.

🚨 We are looking for a research specialist (lab manager) for my lab at Emory (translational-lab.com).

tinyurl.com/muer3ybb

* Great match to prepare for clinical psych or computational cog sci grad school
* Time reserved each week for independent work/professional development

Please RT 🔄 !

Join the Thought Dynamics Lab! 💭
We seek PhD students passionate about computational psychiatry, thought dynamics, NLP, communication, and semantic alignment.
🔗 sites.google.com/view/thought...

Consider applying for the new, prestigious, and generous Insight Scholarship!

Our lab has an opening for a postdoctoral fellow. We're working on models of planning and their disruption in anxiety. We have access to OPM-MEG scanning, VR, and deep phenotyping of clinical and non-clinical populations. Apply now! see here:
www.linkedin.com/jobs/view/41...

If you are coming to #ISCOP, please check out the cool🆕work from our thought dynamics lab! 💭
Semantic cognition, Interacting minds🧠, Computational modeling🧮, Ostracism, Social dynamics.

Thought Dynamics Lab We study thought, communication, and psychopathology

Join the Thought Dynamics Lab!💭
We seek postdocs passionate about computational psychiatry, thought dynamics, NLP, communication, and semantic alignment.
sites.google.com/view/thought...

Consider applying for the prestigious Azrieli Post-Doctoral Fellowship: azrielifoundation.org/fellows/inte...

Thought Dynamics Lab We study thought, communication, and psychopathology

If you find this work interesting, and would like to know more about how we use modeling and NLP to uncover semantic processes and mentalization in interacting individuals, please get in touch or see our lab website sites.google.com/view/thought...

I want to thank my amazing collaborators, Ray Dolan, Rani Moran, @drrickadams.bsky.social, and Noam Siegelman, Max Planck Centre for Computational Psychiatry, Editor and reviewers at Nature Mental Health, as well as the EU Horizon 2020 MSCA-IF program for supporting this work.

Our findings also extend previous work using NLP to characterize language incoherence in psychosis in a large, general population sample, thereby allowing for rigorous testing of the psychometric properties of different NLP measures.

Our finding that alterations in speech and thought are relatively specific is striking given the ubiquity of transdiagnostic findings in psychopathology. Notably, the relevant dimensions were distinctly interpersonal, reflecting the inherently social nature of language.

Whereas Formal Thought Disorder, prevalent in psychosis, is usually diagnosed based on speech incoherence, computational modeling of associative output allowed us to uncover disorganized semantic retrieval as a core mechanism, evident even when language output is intact.

Our findings suggest a core mechanism underlying language incoherence in psychosis is more widespread than commonly assumed, while also showing notable specificity to particular dimensions of psychopathology.

We aimed to map alterations in thought and discourse across dimensions of psychopathology and detail their underlying mechanisms. We combine a transdiagnostic approach, inspired by @clairegillan.bsky.social, @tobywise.bsky.social, and others, with NLP and comp. modeling of associative thinking.

I’m excited to share our new, open-access paper published today in NatMentHealth, “Latent mechanisms of language disorganization relate to specific dimensions of psychopathology”. www.nature.com/articles/s44...