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Dan Handwerker

@danielhandwerker.bsky.social

Neuroscience & fMRI methodology researcher. Views are my own.

1,517 Followers  |  355 Following  |  366 Posts  |  Joined: 30.10.2023
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Posts by Dan Handwerker (@danielhandwerker.bsky.social)

I was sure the illusion would break at some length: can't keep grow forever, right?

Wrong. My brain hurts.

23.02.2026 11:18 — šŸ‘ 57    šŸ” 13    šŸ’¬ 1    šŸ“Œ 2

Probably ok unless you're arriving Sunday late afternoon / evening. @capitalweather.bsky.social updates often and usually has the most details and explanations on the range of possible storm outcomes.

22.02.2026 01:32 — šŸ‘ 0    šŸ” 1    šŸ’¬ 1    šŸ“Œ 0
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Imaging the spontaneous flow of thought: Distinct periods of cognition contribute to dynamic functional connectivity during rest Brain functional connectivity (FC) changes have been measured across seconds using fMRI. This is true for both rest and task scenarios. Moreover, it i…

Not ICA, but this is using connectivity maps that are mapped to neurosynth labels. A very similar approach could be applied to ICA. This isn't hard to do, but I'd say all work like this should be interpreted with caution. www.sciencedirect.com/science/arti...

20.02.2026 18:41 — šŸ‘ 1    šŸ” 0    šŸ’¬ 0    šŸ“Œ 0

I also like building my own stuff, but if you're building something that you want others to possibly use, I wouldn't trust any AI to understand image header nuances yet. Chris Rorden knows them as well, if not better, than anyone & leads NiiVue, MRIcron, dcm2nii, +.

20.02.2026 14:06 — šŸ‘ 1    šŸ” 0    šŸ’¬ 0    šŸ“Œ 0
[AFNI Academy] APQC HTML: Overview
YouTube video by AFNI Bootcamp [AFNI Academy] APQC HTML: Overview

An example of niivue integration in AFNI's QC html report. youtu.be/hD9zTGMrAzQ?...

20.02.2026 01:22 — šŸ‘ 2    šŸ” 0    šŸ’¬ 0    šŸ“Œ 0
NiiVue | NiiVue Description will go into a meta tag in <head />

Or just use niivue.com with a really robust built-in API.

20.02.2026 01:19 — šŸ‘ 8    šŸ” 0    šŸ’¬ 3    šŸ“Œ 0

For context, this was a $50K+ full page ad in the NY Times.

13.02.2026 11:01 — šŸ‘ 3    šŸ” 0    šŸ’¬ 0    šŸ“Œ 0
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From the neuro community on Reddit: Someone should really hire a neuroscientist at USC to look over their press releases... Explore this post and more from the neuro community

I just don't get why people keep relying on AI for stuff like this when one can get similar quality neuroscience images without AI. www.reddit.com/r/neuro/comm...

13.02.2026 01:53 — šŸ‘ 11    šŸ” 0    šŸ’¬ 1    šŸ“Œ 0

True story: it took me years to get a passport in my late 20s - at the time I did not have a single piece of identification with my name spelled correctly. All different misspellings. I eventually found a sympathetic clerk who was like 'I can see what happened here'.

11.02.2026 18:38 — šŸ‘ 468    šŸ” 6    šŸ’¬ 8    šŸ“Œ 0
Positions Available This is the webpage for the Section on Functional Imaging Methods at the National Institute of Mental Health.

Postdoc position to work on neuroimaging methods with @fmri-today.bsky.social (and me) fim.nimh.nih.gov/positions-av...

21.01.2026 22:09 — šŸ‘ 5    šŸ” 7    šŸ’¬ 0    šŸ“Œ 0
People

Over the years, I have written a few Jupyter/Rmd/Matlab notebooks that attempt to teach some statistical concepts, particularly in neuroimaging. You can find them here: www.mrc-cbu.cam.ac.uk/people/rik.h..., though I will say a bit more about each one in a number of posts over next few days.

19.01.2026 17:46 — šŸ‘ 68    šŸ” 27    šŸ’¬ 6    šŸ“Œ 0
The Effects of Generative AI on High-Skilled Work: Evidence from Three Field Experiments with Software Developers This study evaluates the effect of generative AI on software developer productivity via randomized controlled trials at Microsoft, Accenture, and an anonymous F

papers.ssrn.com/sol3/papers....

13.01.2026 03:29 — šŸ‘ 1    šŸ” 0    šŸ’¬ 2    šŸ“Œ 0

I am recruiting a Postdoc to join my lab at UMN. If you or someone you know is interested in studying individual differences in brain and cognitive aging, check out the listing and my website in my bio and apply!

I appreciate RTs to help get the word out as well :)

09.01.2026 21:13 — šŸ‘ 15    šŸ” 16    šŸ’¬ 1    šŸ“Œ 0

With some trepidation, I'm putting this out into the world:
gershmanlab.com/textbook.html
It's a textbook called Computational Foundations of Cognitive Neuroscience, which I wrote for my class.

My hope is that this will be a living document, continuously improved as I get feedback.

09.01.2026 01:27 — šŸ‘ 584    šŸ” 237    šŸ’¬ 16    šŸ“Œ 10

I'll also stress that I think this is nice data that prompts good discussion. From past experience, Nat Neuro likes publishing & promoting "Are we doing everything wrong?" manuscripts. Even if the text is more nuanced, I wished NN better supported & prepped the authors for the inevitable hyping. 5/5

07.01.2026 14:44 — šŸ‘ 6    šŸ” 0    šŸ’¬ 0    šŸ“Œ 0

Also, did you collect or analyze respiratory & cardiac traces, particularly for pCASL? I've found chest movement can create problematic artifacts and higher noise levels in the tag-control subtraction. I'm not sure there's a great correction, but it's worth understanding if there's an issue. 4/5

07.01.2026 14:44 — šŸ‘ 2    šŸ” 0    šŸ’¬ 1    šŸ“Œ 0

When originally skimming your paper, my first thoughts were this is plausible, but the deviations from previous assumptions were much larger than I'd expect given previous work in this area. Calculating and sharing empirical values for noise at each analysis step would help contextualize this. 3/5

07.01.2026 14:44 — šŸ‘ 3    šŸ” 0    šŸ’¬ 1    šŸ“Œ 0

Do you have empirical noise estimates from your existing data or phantom data that can be used to define more appropriate noise levels for @alexanderhuth.bsky.social's simulation? 2/5

07.01.2026 14:44 — šŸ‘ 2    šŸ” 0    šŸ’¬ 1    šŸ“Œ 0

@vavatin.bsky.social . Measures like CBF can be very noisy because they are the subtraction of two noisy time series, and you are also using models that multiply and divide data sources that can scale noise levels. 1/5

07.01.2026 14:44 — šŸ‘ 2    šŸ” 0    šŸ’¬ 1    šŸ“Œ 0

Five years ago, I had a very sick child and referrals to several pediatric medical specialists and tests in a building a few blocks from the US Capitol. The kid got a diagnosis. Treatment worked. But for me, January 6, 2020 means memories of rescheduling medical appointments for a very sick child.

06.01.2026 15:57 — šŸ‘ 5    šŸ” 1    šŸ’¬ 1    šŸ“Œ 0

I suspected something similar, but thank you for creating a simulation and demonstration. I love papers that try to collect more quantitative information to push our understanding of MRI measurements, but we always need to grapple with measurement noise. The openly shared data do look interesting.

05.01.2026 19:06 — šŸ‘ 19    šŸ” 0    šŸ’¬ 1    šŸ“Œ 0
Post image

So I made a little simulation where there is no actual discordance, i.e. the underlying values from which the CBF, CBV, BOLD, and T2* are measured all move in lockstep. With zero noise this gives you zero discordant voxels (nice little diagonal line).

05.01.2026 17:22 — šŸ‘ 11    šŸ” 1    šŸ’¬ 1    šŸ“Œ 0
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NIH Lays Groundwork for Advances in Brain Imaging Data is now emerging from the Connectome 2 - an ultra-high-resolution brain imaging system installed at Mass General Hospital - revealing the power and potential of this technology. The imaging techni...

nihrecord.nih.gov/2026/01/02/n...

02.01.2026 18:08 — šŸ‘ 5    šŸ” 0    šŸ’¬ 0    šŸ“Œ 0

FWIW, this is my limited experience with pCASL. We tried a breath holding + paced breathing task and realized that the chest movement from paced breathing had a big effect on the tag-control calculation even without any tagging pulse. fim.nimh.nih.gov/assets/prese...

23.12.2025 03:02 — šŸ‘ 1    šŸ” 0    šŸ’¬ 0    šŸ“Œ 0

"...where the classic BOLD assumptions fail" -> "...where the classic assumptions about the relationship between the BOLD contrast and neural activity fail"

22.12.2025 19:28 — šŸ‘ 2    šŸ” 0    šŸ’¬ 1    šŸ“Œ 0

One thing I'm keeping in mind for my closer read is that my limited experience with pCASL had results that were VERY sensitive to chest movement. While skimming, I didn't see any mention of chest movement or cardiac traces. 2/2

22.12.2025 18:58 — šŸ‘ 3    šŸ” 0    šŸ’¬ 5    šŸ“Œ 0

I'm also trying to block of time to read this carefully & it definitely seems worth a close read. Edge cases where the classic BOLD assumptions fail don't surprise me, but this seems to be more widespread than I'd expect, and in contradiction to past work. 1/2

22.12.2025 18:58 — šŸ‘ 6    šŸ” 0    šŸ’¬ 1    šŸ“Œ 0

5

22.12.2025 02:20 — šŸ‘ 1    šŸ” 0    šŸ’¬ 0    šŸ“Œ 0
Five channukiot with all 8 candles lit.

Five channukiot with all 8 candles lit.

22.12.2025 02:04 — šŸ‘ 7    šŸ” 0    šŸ’¬ 1    šŸ“Œ 0
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Become a Summer Intern in DCEG DCEG offers a summer research internship in cancer epidemiology, biostatistics, or genetics fo college, postbaccalaureate masters-level students, and graduate students, including medical and dental st...

The #NIH IRP Summer (paid!) Internship Program for 2026 has opened its application portal. This opportunity is open to US Citizens who are college students (including rising first-years), postbaccalaureate, and graduate students, including medical and dental. The deadline is 2026/02/18!

15.12.2025 18:01 — šŸ‘ 19    šŸ” 20    šŸ’¬ 0    šŸ“Œ 2