Johannes Kappel
@johanneskappel.bsky.social
Neuroscientist, working on connectomics & cognition. EMBO Postdoctoral Fellow @ FMI Basel 🇨🇭
Reposted by Johannes Kappel
Come on Konrad, why do you cave so easily? Here, let me try it for you:
1. Spikes are (to good approximation) the only events that matter.
2. Extracellular fields are one way by which spikes interact with each other.
1/2
1. Spikes are (to good approximation) the only events that matter.
2. Extracellular fields are one way by which spikes interact with each other.
1/2
As we are having a discussion on neural codes: @earlkmiller.bsky.social is entirely right that the "only spike rates matter" idea that is so prominent in neuroscience has no credible evidence. We simply do not currently know how neurons code relevant information. Oscillations are likely part of it.
November 21, 2025 at 3:51 PM
Come on Konrad, why do you cave so easily? Here, let me try it for you:
1. Spikes are (to good approximation) the only events that matter.
2. Extracellular fields are one way by which spikes interact with each other.
1/2
1. Spikes are (to good approximation) the only events that matter.
2. Extracellular fields are one way by which spikes interact with each other.
1/2
"[...], in principle, the humans on our team could have come up with it unaided. Nevertheless, we only found it after constructing the AI system."
1. New preprint resolving a conundrum in systems neuroscience with an AI scientist, and humans Reilly Tilbury, Dabin Kwon, @haydari.bsky.social, @jacobmratliff.bsky.social, @bio-emergent.bsky.social, @carandinilab.net, @kevinjmiller.bsky.social, @neurokim.bsky.social
www.biorxiv.org/content/10.1...
www.biorxiv.org/content/10.1...
Characterizing neuronal population geometry with AI equation discovery
The visual cortex contains millions of neurons, whose combined activity forms a population code representing visual stimuli. There is, however, a discrepancy between our understanding of this code at ...
www.biorxiv.org
November 17, 2025 at 7:46 PM
"[...], in principle, the humans on our team could have come up with it unaided. Nevertheless, we only found it after constructing the AI system."
Reposted by Johannes Kappel
Capitalism certainly does not fund science to speak truth to power. But precisely because science cannot make due without a concept of truth, it sometimes cannot help but speak truth to power anyways. An obvious case is climate change, where scientific truth conflicts clearly with the profit motive.
November 17, 2025 at 3:12 PM
Capitalism certainly does not fund science to speak truth to power. But precisely because science cannot make due without a concept of truth, it sometimes cannot help but speak truth to power anyways. An obvious case is climate change, where scientific truth conflicts clearly with the profit motive.
Reposted by Johannes Kappel
In applying AI to material science, biology, etc, capitalism is trying to shed science.
The point is to substitute the engineering of a machine that can generate what science has hitherto done, but without having people know things. Knowledge ultimately residing in private property is the dream.
The point is to substitute the engineering of a machine that can generate what science has hitherto done, but without having people know things. Knowledge ultimately residing in private property is the dream.
Jeff Bezos Creates A.I. Start-Up Where He Will Be Co-Chief Executive
www.nytimes.com
November 17, 2025 at 3:12 PM
In applying AI to material science, biology, etc, capitalism is trying to shed science.
The point is to substitute the engineering of a machine that can generate what science has hitherto done, but without having people know things. Knowledge ultimately residing in private property is the dream.
The point is to substitute the engineering of a machine that can generate what science has hitherto done, but without having people know things. Knowledge ultimately residing in private property is the dream.
Reposted by Johannes Kappel
It is actually an incredibly frustrating time to be a theoretical neuroscientist right now imo, for this reason
Same for neuroscience. The lack of ability to measure many neurons’ activity, perturb them, and measure intracellular processes and connections is what limits understanding the brain.
The key barriers are not algorithms or AI.
🧪#neuroscience 🧠🤖 #MLSky
The key barriers are not algorithms or AI.
🧪#neuroscience 🧠🤖 #MLSky
November 17, 2025 at 1:23 AM
It is actually an incredibly frustrating time to be a theoretical neuroscientist right now imo, for this reason
Reposted by Johannes Kappel
What is the most profitable industry in the world, this side of the law? Not oil, not IT, not pharma.
It's *scientific publishing*.
We call this the Drain of Scientific Publishing.
Paper: arxiv.org/abs/2511.04820
Background: doi.org/10.1162/qss_...
Thread @markhanson.fediscience.org.ap.brid.gy 👇
It's *scientific publishing*.
We call this the Drain of Scientific Publishing.
Paper: arxiv.org/abs/2511.04820
Background: doi.org/10.1162/qss_...
Thread @markhanson.fediscience.org.ap.brid.gy 👇
November 12, 2025 at 10:31 AM
What is the most profitable industry in the world, this side of the law? Not oil, not IT, not pharma.
It's *scientific publishing*.
We call this the Drain of Scientific Publishing.
Paper: arxiv.org/abs/2511.04820
Background: doi.org/10.1162/qss_...
Thread @markhanson.fediscience.org.ap.brid.gy 👇
It's *scientific publishing*.
We call this the Drain of Scientific Publishing.
Paper: arxiv.org/abs/2511.04820
Background: doi.org/10.1162/qss_...
Thread @markhanson.fediscience.org.ap.brid.gy 👇
Reposted by Johannes Kappel
To me, this is one of the key aspects of generative AI's broader environmental, social and climate harm: it cannot exist in an efficient, lean and narrowly applied way.
It only ever looks like it "works" when it's brute-forced: just like Bitcoin. The harm is baked into its characteristics.
It only ever looks like it "works" when it's brute-forced: just like Bitcoin. The harm is baked into its characteristics.
Artificial Intelligence Wants to Sell You Stuff While the World Burns
Meta is betting on generative AI for a new generation of aggressive advertising. It requires immense energy, much of which will likely come from fossil fuels.
newrepublic.com
November 11, 2025 at 8:35 PM
To me, this is one of the key aspects of generative AI's broader environmental, social and climate harm: it cannot exist in an efficient, lean and narrowly applied way.
It only ever looks like it "works" when it's brute-forced: just like Bitcoin. The harm is baked into its characteristics.
It only ever looks like it "works" when it's brute-forced: just like Bitcoin. The harm is baked into its characteristics.
Reposted by Johannes Kappel
What if we did a single run and declared victory
October 23, 2025 at 2:28 AM
What if we did a single run and declared victory
Reposted by Johannes Kappel
MIT rejects "compact" proposed by the Trump administration.
MIT prez wrote: it "would restrict freedom of expression and our independence as an institution" and "is inconsistent with our core belief that scientific funding should be based on scientific merit alone."
orgchart.mit.edu/letters/rega...
MIT prez wrote: it "would restrict freedom of expression and our independence as an institution" and "is inconsistent with our core belief that scientific funding should be based on scientific merit alone."
orgchart.mit.edu/letters/rega...
Regarding the Compact | MIT Organization Chart
orgchart.mit.edu
October 10, 2025 at 1:20 PM
MIT rejects "compact" proposed by the Trump administration.
MIT prez wrote: it "would restrict freedom of expression and our independence as an institution" and "is inconsistent with our core belief that scientific funding should be based on scientific merit alone."
orgchart.mit.edu/letters/rega...
MIT prez wrote: it "would restrict freedom of expression and our independence as an institution" and "is inconsistent with our core belief that scientific funding should be based on scientific merit alone."
orgchart.mit.edu/letters/rega...
Reposted by Johannes Kappel
I've been waiting some years to make this joke and now it’s real:
I conned somebody into giving me a faculty job!
I’m starting as a W1 Tenure-Track Professor at Goethe University Frankfurt in a week (lol), in the Faculty of CS and Math
and I'm recruiting PhD students 🤗
I conned somebody into giving me a faculty job!
I’m starting as a W1 Tenure-Track Professor at Goethe University Frankfurt in a week (lol), in the Faculty of CS and Math
and I'm recruiting PhD students 🤗
a man wearing a white shirt and tie smiles in front of a window
ALT: a man wearing a white shirt and tie smiles in front of a window
media.tenor.com
September 23, 2025 at 1:00 PM
I've been waiting some years to make this joke and now it’s real:
I conned somebody into giving me a faculty job!
I’m starting as a W1 Tenure-Track Professor at Goethe University Frankfurt in a week (lol), in the Faculty of CS and Math
and I'm recruiting PhD students 🤗
I conned somebody into giving me a faculty job!
I’m starting as a W1 Tenure-Track Professor at Goethe University Frankfurt in a week (lol), in the Faculty of CS and Math
and I'm recruiting PhD students 🤗
Reposted by Johannes Kappel
You asked for it! We delivered Quack-O-Grams to our members of Congress urging them to #ImpeachRFK, and get that Quack out of office!
There's still time for you to get in on this fluffy, feathery action: Send your own duck at zurl.co/W1ZnB and keep the momentum going! 🦆
There's still time for you to get in on this fluffy, feathery action: Send your own duck at zurl.co/W1ZnB and keep the momentum going! 🦆
September 17, 2025 at 9:34 PM
You asked for it! We delivered Quack-O-Grams to our members of Congress urging them to #ImpeachRFK, and get that Quack out of office!
There's still time for you to get in on this fluffy, feathery action: Send your own duck at zurl.co/W1ZnB and keep the momentum going! 🦆
There's still time for you to get in on this fluffy, feathery action: Send your own duck at zurl.co/W1ZnB and keep the momentum going! 🦆
Reposted by Johannes Kappel
Only single cell sequencing of the all these post docs will reveal why
September 19, 2025 at 8:54 AM
Only single cell sequencing of the all these post docs will reveal why
Reposted by Johannes Kappel
Preprint -
Excited to present WHOLISTIC, which extends the concept of whole-brain functional imaging to the entire body. Pioneering work by incredibly talented Virginia Ruetten @vmsruetten.bsky.social, this platform reveals whole-organism cellular dynamics in vivo.
www.biorxiv.org/content/10.1...
Excited to present WHOLISTIC, which extends the concept of whole-brain functional imaging to the entire body. Pioneering work by incredibly talented Virginia Ruetten @vmsruetten.bsky.social, this platform reveals whole-organism cellular dynamics in vivo.
www.biorxiv.org/content/10.1...
September 8, 2025 at 4:25 PM
Preprint -
Excited to present WHOLISTIC, which extends the concept of whole-brain functional imaging to the entire body. Pioneering work by incredibly talented Virginia Ruetten @vmsruetten.bsky.social, this platform reveals whole-organism cellular dynamics in vivo.
www.biorxiv.org/content/10.1...
Excited to present WHOLISTIC, which extends the concept of whole-brain functional imaging to the entire body. Pioneering work by incredibly talented Virginia Ruetten @vmsruetten.bsky.social, this platform reveals whole-organism cellular dynamics in vivo.
www.biorxiv.org/content/10.1...
Reposted by Johannes Kappel
@benhayden.bsky.social
@tyrellturing.bsky.social
@jmgrohneuro.bsky.social
@pessoabrain.bsky.social
I see a lot of talk on here about how we should avoid
"x does y" talk because the brain is "a dynamic, reverberant, reciprocally interconnected system".
But this does not follow.
A thread...
@tyrellturing.bsky.social
@jmgrohneuro.bsky.social
@pessoabrain.bsky.social
I see a lot of talk on here about how we should avoid
"x does y" talk because the brain is "a dynamic, reverberant, reciprocally interconnected system".
But this does not follow.
A thread...
September 5, 2025 at 9:57 PM
@benhayden.bsky.social
@tyrellturing.bsky.social
@jmgrohneuro.bsky.social
@pessoabrain.bsky.social
I see a lot of talk on here about how we should avoid
"x does y" talk because the brain is "a dynamic, reverberant, reciprocally interconnected system".
But this does not follow.
A thread...
@tyrellturing.bsky.social
@jmgrohneuro.bsky.social
@pessoabrain.bsky.social
I see a lot of talk on here about how we should avoid
"x does y" talk because the brain is "a dynamic, reverberant, reciprocally interconnected system".
But this does not follow.
A thread...
Reposted by Johannes Kappel
Sad day for peope who still believe brain areas are the primary organizational units of function in the brain.
www.nature.com/articles/s41...
www.nature.com/articles/s41...
A brain-wide map of neural activity during complex behaviour - Nature
The International Brain Laboratory presents a brain-wide electrophysiological map obtained from pooling data from 12 laboratories that performed the same standardized perceptual decision-making task i...
www.nature.com
September 4, 2025 at 11:17 AM
Sad day for peope who still believe brain areas are the primary organizational units of function in the brain.
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Reposted by Johannes Kappel
I hope that when RFK Jr dies someday, someone has been hired and trained to capture whatever crawls out of the body, so that it doesn't find a new host
August 30, 2025 at 3:11 AM
I hope that when RFK Jr dies someday, someone has been hired and trained to capture whatever crawls out of the body, so that it doesn't find a new host
Reposted by Johannes Kappel
I wrote a Comment on neurotheory, and now you can read it!
Some thoughts on where neurotheory has and has not taken root within the neuroscience community, how it has shaped those subfields, and where we theorists might look next for fresh adventures.
www.nature.com/articles/s41...
Some thoughts on where neurotheory has and has not taken root within the neuroscience community, how it has shaped those subfields, and where we theorists might look next for fresh adventures.
www.nature.com/articles/s41...
Theoretical neuroscience has room to grow
Nature Reviews Neuroscience - The goal of theoretical neuroscience is to uncover principles of neural computation through careful design and interpretation of mathematical models. Here, I examine...
www.nature.com
August 20, 2025 at 4:09 PM
I wrote a Comment on neurotheory, and now you can read it!
Some thoughts on where neurotheory has and has not taken root within the neuroscience community, how it has shaped those subfields, and where we theorists might look next for fresh adventures.
www.nature.com/articles/s41...
Some thoughts on where neurotheory has and has not taken root within the neuroscience community, how it has shaped those subfields, and where we theorists might look next for fresh adventures.
www.nature.com/articles/s41...
Reposted by Johannes Kappel
"Your job is not to turn in completed assignments; it's to learn how to think."
cdh.princeton.edu/blog/2025/08...
cdh.princeton.edu/blog/2025/08...
The Incompatibilities Between Generative AI and Art: Q&A with Ted Chiang
The Incompatibilities Between Generative AI and Art: Q&A with Ted Chiang
cdh.princeton.edu
August 16, 2025 at 6:42 AM
"Your job is not to turn in completed assignments; it's to learn how to think."
cdh.princeton.edu/blog/2025/08...
cdh.princeton.edu/blog/2025/08...
Reposted by Johannes Kappel
Total disaster for the #drosophila community if flybase disappears
August 13, 2025 at 8:42 PM
Total disaster for the #drosophila community if flybase disappears
Reposted by Johannes Kappel
Never ask postdocs what they'll be doing next year, that's considered terribly offensive in their culture.
August 7, 2025 at 3:20 PM
Never ask postdocs what they'll be doing next year, that's considered terribly offensive in their culture.
Reposted by Johannes Kappel
📰 I really enjoyed writing this article with @thetransmitter.bsky.social! In it, I summarize parts of our recent perspective article on neural manifolds (www.nature.com/articles/s41...), with a focus on highlighting just a few cool insights into the brain we've already seen at the population level.
Neural manifold properties can help us understand how animal brains deal with competing and multifaceted information, execute flexible behaviors and reuse common computations, writes @mattperich.bsky.social.
#neuroskyence
www.thetransmitter.org/neural-dynam...
#neuroskyence
www.thetransmitter.org/neural-dynam...
Neural population-based approaches have opened new windows into neural computations and behavior
Neural manifold properties can help us understand how animal brains deal with complex information, execute flexible behaviors and reuse common computations.
www.thetransmitter.org
August 4, 2025 at 6:45 PM
📰 I really enjoyed writing this article with @thetransmitter.bsky.social! In it, I summarize parts of our recent perspective article on neural manifolds (www.nature.com/articles/s41...), with a focus on highlighting just a few cool insights into the brain we've already seen at the population level.
Reposted by Johannes Kappel
Go for it. I don't even care any more.
August 2, 2025 at 5:13 AM
Go for it. I don't even care any more.
Reposted by Johannes Kappel
Great resource, out today in @natneuro.nature.com:
An integrated single-nucleus and spatial transcriptomics atlas reveals the molecular landscape of the human hippocampus
@stephaniehicks.bsky.social @martinowk.bsky.social & colleagues
🧪🧠🧬
www.nature.com/articles/s41...
An integrated single-nucleus and spatial transcriptomics atlas reveals the molecular landscape of the human hippocampus
@stephaniehicks.bsky.social @martinowk.bsky.social & colleagues
🧪🧠🧬
www.nature.com/articles/s41...
An integrated single-nucleus and spatial transcriptomics atlas reveals the molecular landscape of the human hippocampus - Nature Neuroscience
The topographical organization of cells in the hippocampus reflects its ability to regulate mood and cognition. Here the authors generate a spatially resolved gene expression map in the human hippocam...
www.nature.com
July 30, 2025 at 5:10 PM
Great resource, out today in @natneuro.nature.com:
An integrated single-nucleus and spatial transcriptomics atlas reveals the molecular landscape of the human hippocampus
@stephaniehicks.bsky.social @martinowk.bsky.social & colleagues
🧪🧠🧬
www.nature.com/articles/s41...
An integrated single-nucleus and spatial transcriptomics atlas reveals the molecular landscape of the human hippocampus
@stephaniehicks.bsky.social @martinowk.bsky.social & colleagues
🧪🧠🧬
www.nature.com/articles/s41...
Reposted by Johannes Kappel
Joint statement on Gaza from AFP, AP, BBC News and Reuters
July 24, 2025 at 9:11 AM
Joint statement on Gaza from AFP, AP, BBC News and Reuters
Reposted by Johannes Kappel
Wake up, babe. A new mapping stimulus just dropped.
July 24, 2025 at 8:29 AM
Wake up, babe. A new mapping stimulus just dropped.