Tomas Knapen
@tknapen.bsky.social
Computational Neuroimaging Researcher based in Amsterdam
Pinned
Tomas Knapen
@tknapen.bsky.social
· Dec 3
Since I need a first bsky post, here's a rehash of @nickhedger.bsky.social's thread announcing our preprint with Kendrick Kay & Thomas Naselaris. TLDR; High-level visual cortex is tiled with maps 'multiplexing' vision and touch. tinyurl.com/seesoma 🧵 1/n
Reposted by Tomas Knapen
This paper had a pretty shocking headline result (40% of voxels!), so I dug into it, and I think it is wrong. Essentially: they compare two noisy measures and find that about 40% of voxels have different sign between the two. I think this is just noise!
Would love to hear expert views on this paper. It appears to show that the operationalization of brain activity the field has relied on for 3 decades—the BOLD response—is not actually a sensible measure of brain activity.
www.nature.com/articles/s41...
www.nature.com/articles/s41...
BOLD signal changes can oppose oxygen metabolism across the human cortex - Nature Neuroscience
Using quantitative brain imaging, the authors show opposite fMRI BOLD signal to metabolic activity due to variable oxygen extraction across the human cortex. This questions the canonical interpretatio...
www.nature.com
January 5, 2026 at 5:22 PM
This paper had a pretty shocking headline result (40% of voxels!), so I dug into it, and I think it is wrong. Essentially: they compare two noisy measures and find that about 40% of voxels have different sign between the two. I think this is just noise!
Reposted by Tomas Knapen
Investigating individual-specific topographic organization has traditionally been a resource-intensive and time-consuming process. But what if we could map visual cortex organization in thousands of brains? Here we offer the community with a toolbox that can do just that! tinyurl.com/deepretinotopy
December 1, 2025 at 11:26 AM
Investigating individual-specific topographic organization has traditionally been a resource-intensive and time-consuming process. But what if we could map visual cortex organization in thousands of brains? Here we offer the community with a toolbox that can do just that! tinyurl.com/deepretinotopy
Reposted by Tomas Knapen
Our team's new publications cover the Nature portfolio! 🧪🧠
- Vision & touch (Nature, rdcu.be/eSsZR)
- Psychedelics (Nat Commun, rdcu.be/eSsZ2)
- Binocular rivalry (Nat Hum Behav, rdcu.be/eSsYW)
- CSF mobility (Nat Neurosci, rdcu.be/eSs0c)
- Numerical cognition (Commun Biol, rdcu.be/eSs0p)
- Vision & touch (Nature, rdcu.be/eSsZR)
- Psychedelics (Nat Commun, rdcu.be/eSsZ2)
- Binocular rivalry (Nat Hum Behav, rdcu.be/eSsYW)
- CSF mobility (Nat Neurosci, rdcu.be/eSs0c)
- Numerical cognition (Commun Biol, rdcu.be/eSs0p)
December 1, 2025 at 9:48 AM
Our team's new publications cover the Nature portfolio! 🧪🧠
- Vision & touch (Nature, rdcu.be/eSsZR)
- Psychedelics (Nat Commun, rdcu.be/eSsZ2)
- Binocular rivalry (Nat Hum Behav, rdcu.be/eSsYW)
- CSF mobility (Nat Neurosci, rdcu.be/eSs0c)
- Numerical cognition (Commun Biol, rdcu.be/eSs0p)
- Vision & touch (Nature, rdcu.be/eSsZR)
- Psychedelics (Nat Commun, rdcu.be/eSsZ2)
- Binocular rivalry (Nat Hum Behav, rdcu.be/eSsYW)
- CSF mobility (Nat Neurosci, rdcu.be/eSs0c)
- Numerical cognition (Commun Biol, rdcu.be/eSs0p)
Reposted by Tomas Knapen
Nature research paper: Vicarious body maps bridge vision and touch in the human brain
go.nature.com/4839zaL
go.nature.com/4839zaL
Vicarious body maps bridge vision and touch in the human brain - Nature
A mode of brain organization that connects visual and bodily reference frames may translate raw sensory impressions into more abstract formats that are useful for action, social cognition and semantic processing.
go.nature.com
November 27, 2025 at 8:36 PM
Nature research paper: Vicarious body maps bridge vision and touch in the human brain
go.nature.com/4839zaL
go.nature.com/4839zaL
New today in @Nature: your visual cortex contains touch-based body maps. bit.ly/VisualBodyMaps
Your brain transforms what you see into first-person, body-referenced codes: A previously unknown bridge between vision and touch.
Your brain transforms what you see into first-person, body-referenced codes: A previously unknown bridge between vision and touch.
November 26, 2025 at 4:01 PM
New today in @Nature: your visual cortex contains touch-based body maps. bit.ly/VisualBodyMaps
Your brain transforms what you see into first-person, body-referenced codes: A previously unknown bridge between vision and touch.
Your brain transforms what you see into first-person, body-referenced codes: A previously unknown bridge between vision and touch.
On the nose
NL funder NWO recently changed rules for grant applications to endorse more modern recognition & reward practices.
But in my reading, the updated preproposal rules (CV, output, & just the slightest teensy weensy hint of a research idea) fully lean into Matthew effect.
Thoughts?
But in my reading, the updated preproposal rules (CV, output, & just the slightest teensy weensy hint of a research idea) fully lean into Matthew effect.
Thoughts?
November 24, 2025 at 6:35 PM
On the nose
Very proud of Marco’s work in this project!
Our new paper is out in Nature Communications! nature.com/articles/s41...
We combined psychophysics, 7T fMRI, and computational modeling of vision with placebo, 5mg, and 10mg psilocybin, in the same group of participants, to clarify the computational mechanisms of psychedelics. 🧵
We combined psychophysics, 7T fMRI, and computational modeling of vision with placebo, 5mg, and 10mg psilocybin, in the same group of participants, to clarify the computational mechanisms of psychedelics. 🧵
November 24, 2025 at 6:17 PM
Very proud of Marco’s work in this project!
Reposted by Tomas Knapen
The paper demonstrating that #psilocybin alters contextual computations is out in @natcomms.nature.com : doi.org/10.1038/s414...
Thanks to the reviewers and coauthors : @marcoaqil.bsky.social , @tknapen.bsky.social , @gillesdehollander.bsky.social , and Nina Vreugdenhil
Thanks to the reviewers and coauthors : @marcoaqil.bsky.social , @tknapen.bsky.social , @gillesdehollander.bsky.social , and Nina Vreugdenhil
November 23, 2025 at 1:14 PM
The paper demonstrating that #psilocybin alters contextual computations is out in @natcomms.nature.com : doi.org/10.1038/s414...
Thanks to the reviewers and coauthors : @marcoaqil.bsky.social , @tknapen.bsky.social , @gillesdehollander.bsky.social , and Nina Vreugdenhil
Thanks to the reviewers and coauthors : @marcoaqil.bsky.social , @tknapen.bsky.social , @gillesdehollander.bsky.social , and Nina Vreugdenhil
Hey everyone at @vssmtg.bsky.social! If you’re interested in pRF fitting, go visit Garikoitz Lerma-Usabiaga’s poster on pRF fitting methods!
For our development of these tools, we’re very interested to hear you want in these tools. Please fill out our questionnaire:
forms.gle/fx5UMs1362jv...
For our development of these tools, we’re very interested to hear you want in these tools. Please fill out our questionnaire:
forms.gle/fx5UMs1362jv...
pRF fitting toolbox wish list
With this form we are taking stock of the field's wishes when it comes to pRF fitting software implementations. We will be presenting the results from this form in our kick-off meeting, and will use t...
docs.google.com
May 17, 2025 at 12:03 PM
Hey everyone at @vssmtg.bsky.social! If you’re interested in pRF fitting, go visit Garikoitz Lerma-Usabiaga’s poster on pRF fitting methods!
For our development of these tools, we’re very interested to hear you want in these tools. Please fill out our questionnaire:
forms.gle/fx5UMs1362jv...
For our development of these tools, we’re very interested to hear you want in these tools. Please fill out our questionnaire:
forms.gle/fx5UMs1362jv...
Reposted by Tomas Knapen
Reposted by Tomas Knapen
𝘗𝘦𝘳𝘴𝘰𝘯, 𝘴𝘵𝘢𝘯𝘥𝘪𝘯𝘨 𝘰𝘯 𝘵𝘩𝘦 𝘣𝘦𝘢𝘤𝘩 𝘥𝘰𝘪𝘯𝘨 𝘺𝘰𝘨𝘢, 𝘴𝘵𝘢𝘯𝘥𝘪𝘯𝘨 𝘰𝘯 𝘰𝘯𝘦 𝘧𝘰𝘰𝘵, 𝘸𝘪𝘵𝘩 𝘰𝘯𝘦 𝘩𝘢𝘯𝘥 𝘰𝘯 𝘵𝘩𝘦 𝘨𝘳𝘰𝘶𝘯𝘥, 𝘤𝘰𝘯𝘵𝘰𝘳𝘵𝘦𝘥 𝘪𝘯 𝘢𝘯 𝘶𝘯𝘶𝘴𝘶𝘢𝘭 𝘢𝘯𝘥 𝘤𝘩𝘢𝘭𝘭𝘦𝘯𝘨𝘪𝘯𝘨 𝘱𝘰𝘴𝘦, 𝘸𝘩𝘪𝘭𝘦 𝘤𝘰𝘯𝘵𝘦𝘮𝘱𝘭𝘢𝘵𝘪𝘯𝘨 𝘵𝘩𝘦 𝘪𝘥𝘦𝘢 𝘵𝘩𝘢𝘵 𝘨𝘦𝘯𝘦𝘳𝘢𝘵𝘪𝘷𝘦 𝘈𝘐 𝘩𝘢𝘴 “𝘸𝘰𝘳𝘭𝘥 𝘮𝘰𝘥𝘦𝘭𝘴”
December 16, 2024 at 1:00 AM
𝘗𝘦𝘳𝘴𝘰𝘯, 𝘴𝘵𝘢𝘯𝘥𝘪𝘯𝘨 𝘰𝘯 𝘵𝘩𝘦 𝘣𝘦𝘢𝘤𝘩 𝘥𝘰𝘪𝘯𝘨 𝘺𝘰𝘨𝘢, 𝘴𝘵𝘢𝘯𝘥𝘪𝘯𝘨 𝘰𝘯 𝘰𝘯𝘦 𝘧𝘰𝘰𝘵, 𝘸𝘪𝘵𝘩 𝘰𝘯𝘦 𝘩𝘢𝘯𝘥 𝘰𝘯 𝘵𝘩𝘦 𝘨𝘳𝘰𝘶𝘯𝘥, 𝘤𝘰𝘯𝘵𝘰𝘳𝘵𝘦𝘥 𝘪𝘯 𝘢𝘯 𝘶𝘯𝘶𝘴𝘶𝘢𝘭 𝘢𝘯𝘥 𝘤𝘩𝘢𝘭𝘭𝘦𝘯𝘨𝘪𝘯𝘨 𝘱𝘰𝘴𝘦, 𝘸𝘩𝘪𝘭𝘦 𝘤𝘰𝘯𝘵𝘦𝘮𝘱𝘭𝘢𝘵𝘪𝘯𝘨 𝘵𝘩𝘦 𝘪𝘥𝘦𝘢 𝘵𝘩𝘢𝘵 𝘨𝘦𝘯𝘦𝘳𝘢𝘵𝘪𝘷𝘦 𝘈𝘐 𝘩𝘢𝘴 “𝘸𝘰𝘳𝘭𝘥 𝘮𝘰𝘥𝘦𝘭𝘴”
Reposted by Tomas Knapen
A thread motivated by a new paper on body representations in the human brain at a fine-grained (multi-unit) level, spearheaded by J Garcia Ramirez, T Theys, and P Janssen, where I was a small part of a bigger collaboration that also included S Bracci, R Murty and @nancykanwisher.bsky.social. 1/n
PNAS
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...
www.pnas.org
December 13, 2024 at 4:15 PM
A thread motivated by a new paper on body representations in the human brain at a fine-grained (multi-unit) level, spearheaded by J Garcia Ramirez, T Theys, and P Janssen, where I was a small part of a bigger collaboration that also included S Bracci, R Murty and @nancykanwisher.bsky.social. 1/n
Since I need a first bsky post, here's a rehash of @nickhedger.bsky.social's thread announcing our preprint with Kendrick Kay & Thomas Naselaris. TLDR; High-level visual cortex is tiled with maps 'multiplexing' vision and touch. tinyurl.com/seesoma 🧵 1/n
December 3, 2024 at 3:13 PM
Since I need a first bsky post, here's a rehash of @nickhedger.bsky.social's thread announcing our preprint with Kendrick Kay & Thomas Naselaris. TLDR; High-level visual cortex is tiled with maps 'multiplexing' vision and touch. tinyurl.com/seesoma 🧵 1/n