Chris Fetsch

We know about cosmological dark matter despite being unable to measure it because, without it, galaxies would fall apart. By analogy, let's talk about "cognitive dark matter" (CDM): brain functions that meaningfully shape behavior but are hard to infer from behavior alone. New paper! 🧵👇

Much love to Alex Pretti and Renee Good—but remember—ICE has killed 9 people in 2026. You know the names of the 2 white people they've killed. ICE has also killed a Black man named Keith Porter, a Cambodian named Parady La, and five Latinos named Heber Sanchaz Domínguez, Victor Manuel Diaz, Luis Beltran Yanez-Cruz, Luis Gustavo Nunez Caceres, and Geraldo Lunas Campos. ICE is on pace to kill more than 100 people this year. Abolish ICE. Impeach Noem. Prosecute those who committed these crimes.

ICE is now responsible for 66% of the homicides in Minneapolis this year.

There is nothing patriotic about what is occurring on Capitol Hill. This is 3rd world style anti-American anarchy.

@AnnDuan2 Super cool, Ann! Look forward to reading.

New preprint from the lab! A frontal motor circuit for economic decisions and actions biorxiv.org/content/10.648… We use a novel task in mice, cortex-wide imaging & optogenetics, NPX recording and modelling to reveal a mechanism that transforms abstract decisions to spatial actions.

Textbook war crime/extrajudicial killing "Two survivors were clinging to the smoldering wreck. The Special Operations commander overseeing the Sept. 2 attack ... ordered a second strike to comply with Hegseth’s instructions." reporting by @AlexHortonTX @nakashimae

@gouki_okazawa Thanks Gouki!

Great work! Neural basis of concurrent deliberation toward a choice and confidence judgment nature.com/articles/s4159…

Are you an aspiring graduate student fascinated with neuroscience and enjoy computation? Apply to my lab at UMD for graduate school: we aim to develop a mechanistic understanding of cortical function using novel computational tools and large-scale neurophysiological data.

What makes me most angry is that there's nothing Americans "get" from destroying USAID in a way that directly results in the death of the world's poorest children. It barely even qualifies as an act of selfishness. We're doing it for nothing. The debt picture is completely unchanged. Being an insanely rich country that controls its own currency means we have a genuinely magical ability to save hundreds of thousands of lives around the world with a budgetary rounding error. And MAGA's like: "No thanks, it sounds woke."

every time someone asks me about my dislike and refusal to use AI, i send them this.

🚨A dangerous moment for America. If the normal police ever pulled something like this — pulling every single person out of an apartment building and handcuffing them to run checks — they would be sued into oblivion. It's beyond unconstitutional. Yet DHS is laughing about it!

*deep sigh*

fire the head coach

Medicine and public health have added three decades to the human lifespan. Vaccination alone produced 40% of the reduction in child deaths. And now a disturbed and unqualified man driven by crackpot theories is destroying the foundations of this work, including CDC.

A memorial to my dead brothers isn’t political. But your cowardly, dead-of-night erasure of it sure is.

"fruit sludge" is right!

Pay attention.

The federal government’s $1B dollar demand is designed for one purpose and one purpose only: to devastate @UCLA and its critical mission. #StandUpForUC to defend America’s greatest public university system and support this life-saving work. ucal.us/standupforuc

This is horrific. What is unfolding is not just a policy change. It is a direct assault on life-saving medical progress. By suppressing mRNA research and halting the development of critical vaccine programs, we are denying people access to some of the most advanced disease-prevention technologies ever developed. mRNA vaccines are no longer just about COVID. They are now being developed to prevent cancers like melanoma and lung cancer, protect newborns from congenital infections like cytomegalovirus (CMV), and defend against global threats like avian influenza, RSV, HIV, malaria, Lyme disease, and Zika. Several of these vaccines are already in Phase 3 trials, and some were just years away from approval. That future is now being deliberately dismantled. This is not a matter of policy disagreement. It is a betrayal of public health, rooted in misinformation and fear. It disregards scientific evidence, abandons medical innovation, and puts millions at long-term risk. The cost will not be measured in dollars. It will be measured in cancers not prevented, diseases not controlled, and lives not saved. The consequences must be called what they are: preventable mass death on a national scale.