Soroush Mirjalili

A neural state space for episodic memories Episodic memories are highly dynamic and change in nonlinear ways over time. This dynamism is not captured by existing systems consolidation theories …

I wrote a thing on episodic memory and systems consolidation. I hope you all enjoy it and/or find it interesting.

A neural state space for episodic memories

www.sciencedirect.com/science/arti...

#neuroskyence #psychscisky #cognition 🧪

When does new learning interfere with existing knowledge in people and ANNs? Great to have this out today in @nathumbehav.nature.com

Work with @summerfieldlab.bsky.social, @tsonj.bsky.social, Lukas Braun and Jan Grohn
www.nature.com/articles/s41...

I will be recruiting 🌟PhD students🌟 for my newish lab! If you're interested in learning & memory mechanisms applied to individual, interactive & collective behavior using computational modeling, real-world experiments and fMRI, email me! RTs much appreciated 🙏 rouhanilab.com

Thank you so much!!

Thanks Ziyao!! :)

This work was a true team effort, and I’d like to thank Wanjia Guo, Dominik Grätz, Eric Wang, Dr. Ulrich Mayr, and Dr. Brice Kuhl for their invaluable help throughout the process. I’m especially grateful to Brice for his guidance and support that extended far beyond this paper.

These findings provide insight into how the hippocampus resolves memory interference 'one dimension at a time', demonstrating highly dynamic and adaptive processes that dramatically increase the representational distance between memories that are most at risk for interference.

Finally, dimension-specific input-output functions in CA3/DG strikingly mirrored the sequential pattern observed in behavior: CA3/DG inverted each similarity dimension when it contributed to memory interference but preserved the dimension when it didn't contribute to interference.

Among the 10 dimensions, the first 2 dimensions of similarity strongly predicted memory interference errors. However, their influence on behavior sharply changed with experience. Whereas one dimension drove interference earlier in learning, the other drove interference later.

First, we generated a set of natural scene images from two visual categories and rigorously characterized similarity using a wide array of methods. We then applied PCA to these similarity matrices to identify orthogonal components (dimensions) of similarity across the 10 metrics.

Hippocampal transformations occur along dimensions of memory interference The role of the hippocampus in resolving memory interference has been greatly elucidated by considering the relationship between the similarity of visual stimuli (input) and corresponding similarity o...

🧠🚨 How does the hippocampus transform the visual similarity space to resolve memory interference?

In this new preprint, we found that the hippocampus sequentially inverts the behaviorally relevant dimensions of similarity 🧵

www.biorxiv.org/content/10.1...

Hippocampal transformations occur along dimensions of memory interference https://www.biorxiv.org/content/10.1101/2025.10.13.682242v1

Excited to share that I'm joining WashU in January as an Assistant Prof in Psych & Brain Sciences! 🧠✨!

I'm also recruiting grad students to start next September - come hang out with us! Details about our lab here: www.deckerlab.com

Reposts are very welcome! 🙌 Please help spread the word!

Years ago my lab tried to brainstorm ways to separately manipulate low-level (texture/pattern) and high-level (scene/object) image properties, for studying visual representations in the brain. Thanks to imaginative work by PhD student Zall Hirschstein, we now have a stimulus set that does just that!

This is really cool!

🚀Excited to share our project: Canonical Representational Mapping for Cognitive Neuroscience. @schottdorflab.bsky.social and I propose a novel multivariate method to isolate neural representations aligned with specific cognitive hypotheses 🧵https://www.biorxiv.org/content/10.1101/2025.09.01.673485v1

Neural and behavioral reinstatement jointly reflect retrieval of narrative events - Nature Communications When people recall a movie, their eye movements and brain activity resemble those observed during the viewing. These behavioral and neural reactivations are linked through a common process, likely ref...

Excited to share our new paper w/ @cibaker.bsky.social in @natcomms.nature.com linking active vision & memory!

We provide evidence that gaze reinstatement & neural reactivation are deeply related phenomena that jointly reflect the experiences constructed during recall. doi.org/10.1038/s414...
🧵1/9

Congrats Ziyao!!

Congrats!!!

Exploration is associated with socioeconomic disparities in learning and academic achievement in adolescence - Nature Communications Children from lower socioeconomic backgrounds often show lower academic achievement, commonly linked to limited resources. Here, the authors show that reduced exploration–a behavior tuned for learning...

Thrilled to share our new @NatureComms
paper: "Exploration is associated with socioeconomic disparities in learning and academic achievement in adolescence." www.nature.com/articles/s41... 🧵1/7

Hippocampal representations drift in stable multisensory environments - Nature Tracking of individual place cells in mouse CA1 shows that representational drift is not influenced by changes in environment or behaviour, and is lower for more excitable place cells.

I’m excited to share my final co-first author paper from my postdoc in Dan Dombeck's lab!

We explored how behavior, senses, and neurons influence how much information in the brain changes over time.

www.nature.com/articles/s41...

#science #research #neuroscience #hippocampus #placecells

AI-guided digital intervention with physiological monitoring reduces intrusive memories after experimental trauma Trauma prevalence is vast globally. Evidence-based digital treatments can help, but most require human guidance. Human guides provide tailored instructions and responsiveness to internal cognitive sta...

I'm excited to share a new preprint! We built a digital, scalable intervention to reduce intrusive memories, combining an AI chatbot with LLM scoring of human-AI conversations and pupillometry predictors of effort and intervention success. I hope you enjoy! arxiv.org/abs/2507.01081

Emotional Arousal‐Induced Episodic Memory Benefits Are Attenuated in Autism Spectrum Disorders, Especially in Older Age Autism Spectrum Disorder (ASD) is a common neurodevelopmental disorder associated with episodic memory impairment. Although emotional factors such as arousal, as well as age and depression symptoms, ...

New paper from our lab in which we show that altered arousal in Autism Spectrum Disorders reduces episodic memory for emotional events. Stronger effects with age support an accelerated aging hypothesis of ASD. onlinelibrary.wiley.com/doi/10.1002/...

Discovering cognitive strategies with tiny recurrent neural networks - Nature Modelling biological decision-making with tiny recurrent neural networks enables more accurate predictions of animal choices than classical cognitive models and offers insights into the underlying cog...

Thrilled to see our TinyRNN paper in @nature! We show how tiny RNNs predict choices of individual subjects accurately while staying fully interpretable. This approach can transform how we model cognitive processes in both healthy and disordered decisions. doi.org/10.1038/s415...

Movie-watching evokes ripple-like activity within events and at event boundaries Nature Communications - The neural processes involved in memory formation for realistic experiences remain poorly understood. Here, the authors found that ripple-like activity in the human...

🧠 Paper out!

We investigated how hippocampal and cortical ripples support memory during movie watching. We found that:

🎬 Hippocampal ripples mark event boundaries
🧩 Cortical ripples predict later recall

Ripples may help transform real-life experiences into lasting memories!

rdcu.be/eui9l

This is really really cool!

Rapid emergence of a maths gender gap in first grade - Nature Boys and girls exhibit very similar maths scores upon school entry, but a gender gap in favour of boys becomes highly significant after 4 months of schooling, which increases with years of schooling,&...

Do girls and boys really differ in their mathematical skills? A recent @nature.com paper by @standehaene.bsky.social et al shows that French boys and girls enter school with similar abilities, but after just four months, boys pull ahead 🧪 www.nature.com/articles/s41...

Congrats!!

Thanks for sharing this, I already linked my submission to this group!

Multi-timescale reinforcement learning in the brain - Nature Individual dopaminergic neurons encode future rewards over distinct temporal horizons.

Our work with Pablo Tano, @hyunggoo-kim.bsky.social Athar Malik, Alexandre Pouget and @naoshigeuchida.bsky.social exploring how dopamine neurons could enable multi-timescale reinforcement learning in the brain is out in @nature.com
www.nature.com/articles/s41...