Tomas Knapen
Computational Neuroimaging Researcher based in Amsterdam
- Reposted by Tomas KnapenThis 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...
- Reposted by Tomas KnapenInvestigating 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 KnapenOur 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)
- Reposted by Tomas KnapenNature research paper: Vicarious body maps bridge vision and touch in the human brain 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.
- The core discovery: Visual cortex isn’t purely visual — it’s tiled with orderly somatotopic maps, aligned with the maps in primary somatosensory cortex. Seeing recruits the same body-based computational machinery you use to feel your own body. x.com/HedgerResear...
- 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. 🧵
- Reposted by Tomas KnapenThe 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
- Psilocybin, the active compound in magic mushrooms, alters perception and induces hallucinations. In this preprint, we show through visual illusions, fMRI and modeling that psilocybin affects contextual computations, a potentially general mechanism of psychedelics. www.biorxiv.org/content/10.1...
- 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...
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- Reposted by Tomas KnapenA 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
