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Chris Chatham

@chchatham.bsky.social
549 followers 764 following 78 posts

Designing experiments to sort the universe of possible medicines for the mind.

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Reposted by Chris Chatham
Evan Gordon @gordonneuro.bsky.social · 22/04/2026
I always assumed that brain function had to line up with cytoarchitectonics. It turns out I was wrong. Human cortex, especially PFC, is tiled by chains of functional patches that subdivide and interlink architectonic areas into parallel processing streams. www.biorxiv.org/content/10.6...
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jonny (leachate composite form) @jo.nny.rip · 29/11/2025
One of the main things neuroscientists do not like to deal with is degeneracy and the irreversibility of the activity -> function relationship, because that would force them to acknowledge that most analysis methods like decoding and functional connectivity are meaningless.
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Natalie Christie Peluso 🧠 @nataliepeluso.com · 27/11/2025
🧠👀 'These findings reveal high-dimensional aspects of cortical representation undetectable with conventional methods, such as RSA, & contradict previous theories suggesting that high-level visual cortex representations are low-dimensional.' #neuroskyence journals.plos.org/ploscompbiol...
journals.plos.org
Universal scale-free representations in human visual cortex
Author summary The human cerebral cortex is thought to encode sensory information in population activity patterns, but the statistical structure of these population codes has yet to be characterized. ...
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Pierre Vanderhaeghen @vanderhaeghenp2.bsky.social · 27/11/2025
Please check out and RT this new position for an exciting collaborative project with @boninlab.bsky.social and @franckp.bsky.social on the links between human-specific mechanisms and neurodevelopmental disorders in cortical circuits.
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Chris Chatham @chchatham.bsky.social · 18/11/2025
Do you have a sense about how far this update might eventually go? I guess your conclusion may apply quite broadly... but are there particular tasks, boundary conditions, or experimental manipulations which you think are still better explained by more classical RL-like striatal processes than habit?
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Chris Chatham @chchatham.bsky.social · 17/11/2025
Very curious if this changes the conclusion from any investigational drugs tested with these tasks. I know you may not be able to say, and/or may no longer have access to those, but i assume this change is expected to alter how drug effects may translate into parameter estimates… 😎 great stuff Anne!
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Chris Chatham @chchatham.bsky.social · 17/11/2025
A structurally profound update to the most comprehensive closed-form model of working memory & RL-like interactions. Really excited to see this evolution - and to learn if this new model might tell us something different about experimental drugs tested with the older task+model. Congrats Anne
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Chris Chatham @chchatham.bsky.social · 15/10/2025
Very proud to have played a part in this work. I am confident that measurements of speech contain signal of use for developing new therapeutics, transdiagnostically...
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Reposted by Chris Chatham
Adam Kucharski @adamjkucharski.bsky.social · 01/09/2025
Results so stunningly clear they inspired this classic xkcd (xkcd.com/2400/):
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Chris Chatham @chchatham.bsky.social · 26/08/2025
I remain somewhat surprised reproducing MA isn't a solved problem by all the folks scrounging around for LLM use cases. One would think that LLMs+tools would have a ready-made training set for learning RL policies on tool calls / finetuning models in the history of meta-analyses published so far.
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Reposted by Chris Chatham
Nick Myers @nick-myers.bsky.social · 26/08/2025
New paper using M/EEG to look at attractive and repulsive serial dependence in working memory, led by the excellent Jiangang Shan, with Jasper Hajonides.
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Chris Chatham @chchatham.bsky.social · 25/08/2025
In fairness, I doubt this aspect of my strategy is representative. I'm also engaging in the strategy you'd assumed (although not w/ any particular hope of success, and w/ a careful eye towards poisoning myself). Anyone seen a carefully reasoned piece on the options from a relevant expert/thinktank?
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Chris Chatham @chchatham.bsky.social · 23/08/2025
One sad lesson I take from Trump 2.0 is that the majority of Americans are no longer capable of reasoned debate. So I fear any liberal worldview that ties itself to that broken vehicle is doomed. A liberal dictum to entirely avoid such spaces requires very solid justification now more than ever IMO
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Chris Chatham @chchatham.bsky.social · 23/08/2025
I understand the argument, but not the basis for believing this has any demonstrable record of success. I suspect we enable the propaganda more by evacuating the space of liberal views than we would by trying to poison the well (e.g., marking “not interested” on every ad, boycotting advertisers etc)
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Chris Chatham @chchatham.bsky.social · 23/08/2025
For one thing, it could just be another propaganda platform that we otherwise willfully grant to the right, adding to the seemingly-effective echo chambers they cultivate in various corners of the popular tech/science/lifestyle podcast world, FoxNews before that, and AM radio syndicate years earlier
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Chris Chatham @chchatham.bsky.social · 23/08/2025
No… I’m saying that despite not doing so, it may yet have value. To suggest the opposite - that its value derives exclusively from enabling debate amongst reasonable people - is potential folly, maybe one of those high-minded liberal values we need to reconsider in light of liberal losses.
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Reposted by Chris Chatham
Arif A. Hamid, Ph.D. @arifahamid.bsky.social · 23/08/2025
Proud of Amy and Nick, who review technical and theoretical gaps in timescales of dopamine fluctuations. We argue that DA fluctuations are hierarchical control signals, and “tonic” DA relays goal alignment across planning horizons and C-BG hierarchy. www.sciencedirect.com/science/arti...
sciencedirect.com
Timescales of dopamine release in the striatum as a window into hierarchical control
The reinforcement learning community has made significant progress in understanding dopamine (DA) in reward learning, cognitive control, and motivatio…
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Chris Chatham @chchatham.bsky.social · 23/08/2025
3 reasons: (1) many folks have no idea professors also do research; (2) it may be seen as gauche to ask, and risk forcing a distinction between research faculty and teaching faculty; (3) you can still respond with how you teach (publish) about what your research has found.
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Chris Chatham @chchatham.bsky.social · 22/08/2025
I'm open to this but I question which high-minded liberal ideas need rethinking given our dismal performance among the evidently-unreasonable majority of American voters; I suspect that 'the value of a communication platform arises from its ability to engage reasonable parties in debate' may be one.
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Chris Chatham @chchatham.bsky.social · 22/08/2025
I confess I haven;t; it's a war of attrition IMO. I also don't think my contributions do much to legitimize the platform so, in the worst case, I see it mostly as a potential waste of time. I'm quote open to being persuaded, just haven't seen a comprehensive/balanced logical argument for vs against.
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Chris Chatham @chchatham.bsky.social · 22/08/2025
I also find the math unclear, and hence continue to engage there so as not to prematurely cede the ground. I concede this may not be terribly effective. But, it seems like the math must surely be clearer to you than you suggest, given the (rather ironically) extreme assertion in the OP!
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Chris Chatham @chchatham.bsky.social · 21/08/2025
This is an encouraging result for the use of EEG in a variety of applications going well beyond RSA.
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Chris Chatham @chchatham.bsky.social · 21/08/2025
Thanks for this great work! Can you explain a bit more about why you selected the similarity metrics you did? I was not sure whether there was a principled reason to use Spearman for dimensions, cosine for content and Pearson for brain or if this mixed bag of metrics simply worked best.
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Reposted by Chris Chatham
Simon W Davis @woodforbrains.bsky.social · 21/08/2025
EEG representational analyses are more robust than fMRI. Huh. link.springer.com/article/10.1...
link.springer.com
How Robust Are fMRI- and EEG-Based Representational Similarity Analysis? - Computational Brain & Behavior
In EEG and fMRI analysis, researchers choose from a combinatorially large set of theoretically indistinguishable options while building a data processing pipeline based on individual beliefs and other...
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Tom Donoghue @tomdonoghue.bsky.social · 21/08/2025
I've updated my literature review of studies of aperiodic neural activity in clinical disorders, adding ~30 papers, taking it to 177 reports across 38 disorders! It's got a review of results so far, discussion of themes & issues, & recommendations for future work! www.medrxiv.org/content/10.1...
medrxiv.org
A systematic review of aperiodic neural activity in clinical investigations
Aperiodic neural activity - activity with no characteristic frequency - has increasingly become a common feature of study, including in clinical work. Reports investigating aperiodic activity from pat...
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Chris Chatham @chchatham.bsky.social · 11/08/2025
Very encouraging work; I'm inspired. What happened with the primary outcome (the LPP)? Regardless of whether the study was positive on its primary outcome, it's obvious there's something here worth exploring further. Congrats!
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Donner Lab @donnerlab.bsky.social · 27/06/2025
1/ New paper by Hame Park, (@AraziAyelet), Bharath Talluri, Marco Celotto, Stefano Panzeri, Alan Stocker & Tobias Donner published in Nature Communications – “Confirmation Bias through Selective Readout of Information Encoded in Human Parietal Cortex”: rdcu.be/etlR7. Here is a summary:
rdcu.be
Confirmation bias through selective readout of information encoded in human parietal cortex
Nature Communications - People often discard incoming information when it contradicts their pre-existing beliefs about the world. Here, the authors show that this discarded information is precisely...
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Chris Chatham @chchatham.bsky.social · 02/04/2025
Super talented team working on an incredibly important problem. Congrats!
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Chris Chatham @chchatham.bsky.social · 25/03/2025
Denali describing their approach to shuttle large molecules as cargo across the blood brain barrier. We should see new clinical data from approaches like this already in 2025. Exciting time for neurotherapeutics for this and so many other reasons...
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bioRxiv Neuroscience @biorxiv-neursci.bsky.social · 25/03/2025
Dual targeting of transferrin receptor and CD98hc enhances brain exposure of large molecules www.biorxiv.org/content/10.1101/202…
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bioRxiv Neuroscience @biorxiv-neursci.bsky.social · 25/03/2025
Intellectual ability and cortical homotopy development in children and adolescents www.biorxiv.org/content/10.1101/202…
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Darren Dahly @statsepi.bsky.social · 24/03/2025
Here is the video I made, inspired by this wonderful tweet. www.youtube.com/watch?v=dSOj...
youtube.com
Why we randomize
YouTube video by Darren Dahly
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Chris Chatham @chchatham.bsky.social · 26/02/2025
Oh - I shoudl also thank @darkhat.bsky.social for sending along this fascinating paper in our now years-long science + everything chat! Keep an eye out for a killer paper, on a totally different topic, coming from his team soon...
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Chris Chatham @chchatham.bsky.social · 26/02/2025
Thus, no clear answers to this mystery yet AFAIK. I am slightly surprised not to see more work trying to crack lithium's protective effects in AD - and more work to stimulate glymphatic clearance or SWS-like rhythms in the elderly. I'm eager to hear some real AD experts opine on all this! Thx (6/6).
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Chris Chatham @chchatham.bsky.social · 26/02/2025
There are of course many possibilities but one that's fascinated me is the apparent influence of lithium vs other antidepressants on slow-wave sleep - that part of sleep recently associated with glymphatic clearance! But this story is also controversial: www.nature.com/articles/s41... (5/n)
nature.com
Brain clearance is reduced during sleep and anesthesia - Nature Neuroscience
It has been widely believed that a key function of sleep is to actively clear metabolites and toxins from the brain. Miao, Luo et al. show in mice that brain clearance is markedly reduced—not increase...
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Chris Chatham @chchatham.bsky.social · 26/02/2025
These discordant pattern of results could veridically imply an iatrogenic effect of antidepressants on dementia risk, as opposed to mere latent confounding. What could possibly be the mechanism? One speculative possibility: many antidepressants alter sleep architecture. Why might that matter? (4/n)
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Chris Chatham @chchatham.bsky.social · 26/02/2025
Of course, this discrepancy might be partly explained by a greater overlap in genetic risk for AD & MDD as compared to BD. But data thus far don't seem to support this view. Take, for example, the perhaps greater Rg between AD & BD as compared to MDD, here: pmc.ncbi.nlm.nih.gov/articles/PMC... (3/n)
pmc.ncbi.nlm.nih.gov
The shared genetic risk architecture of neurological and psychiatric disorders: a genome-wide analysis
While neurological and psychiatric disorders have historically been considered to reflect distinct pathogenic entities, recent findings suggest shared pathobiological mechanisms. However, the extent t...
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Chris Chatham @chchatham.bsky.social · 26/02/2025
The paper above putatively demonstrates a link between antidepressant use and dementia risk. Intriguing, a variety of prior work implies a *protective* role of lithium on the incidence of dementia - even in the drinking water! Here's one such study: jamanetwork.com/journals/jam... (2/n)
jamanetwork.com
Association of Lithium in Drinking Water With Dementia Incidence
This case-control study investigates whether the incidence of dementia in the general population covaries with long-term exposure to microlevels of lithium in drinking water.
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Chris Chatham @chchatham.bsky.social · 26/02/2025
How did these authors, reviewers and editors all entirely fail to note the fascinating discrepancy beween this finding and the protective effect of lithium for AD? bmcmedicine.biomedcentral.com/articles/10.... There's such an interesting discussion to be had on that! (1/n)
bmcmedicine.biomedcentral.com
Antidepressant use and cognitive decline in patients with dementia: a national cohort study - BMC Medicine
Background Dementia is associated with psychiatric symptoms but the effects of antidepressants on cognitive function in dementia are understudied. We aimed to investigate the association between antid...
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Chris Chatham @chchatham.bsky.social · 20/02/2025
Incredibly talented group and super important work from these teams at Boston Children's - great training opportunity for new PhDs thinking about a postdoc.
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Rich Law @drrichjlaw.bsky.social · 19/02/2025
As @dereklowe.bsky.social was asking, we need more pharma CEOs to speak up! Merck, Pfizer, Lilly, Amgen - where are your voices?! (BTW- really read to the bottom of this).
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Caitlin S., PhD @paleophile.bsky.social · 19/02/2025
The Democrats on the House Science Committee have set up a website to collect stories from fired federal employees, anonymously if desired. Please amplify. (This helps the lawyers establish standing for bringing legal cases against the administration!) democrats-science.house.gov/sciencefirings
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John Felt @jfeltphd.bsky.social · 19/02/2025
Will shadish had a great paper on this where participants were randomized to choose their condition or to be randomly assigned to condition www.statpower.net/Content/MLRM...
statpower.net
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Julia M. Rohrer @dingdingpeng.the100.ci · 18/02/2025
New guest post! Excluding "careless" responses is a routine practice in many contexts. But if careless responding itself is an outcome of the variables of interest, that may actually cause trouble.
In this scenario, we are interested in the effect of X on Y. However, careless responding is affected by Y. If we exclude respondents who show signs of careless responding -- and thus condition on this node -- we potentially bias our estimate of the effect of X on Y.
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Alejandro de la Vega @neurozorro.bsky.social · 14/02/2025
@briannosek.bsky.social I'm not sure if you're aware but your work on the reproducibility crisis is being cited by the Heritage Foundation to motivate the huge cuts to indirect costs we are seeing at NIH. How do you respond to this? www.heritage.org/sites/defaul...
heritage.org
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Phil Corlett @philcorlett.bsky.social · 13/02/2025
New preprint: elaborating the domain-general prediction error driven account of paranoia and delusion contents: osf.io/preprints/ps... Awesome to work with @praveensuthaharan.bsky.social Rosa Rossi-Goldthorpe, @juliasheffield.bsky.social, Santiago Castiello, and @celiaheyes.bsky.social on this
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Chris Chatham @chchatham.bsky.social · 13/02/2025
More killer stuff from the Roche EEG team. Wow
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Xiaosi Gu @xiaosigu.bsky.social · 07/02/2025
Super excited to share this paper that just came out today in@naturementalhealth.bsky.social led by @sarahbanker.bsky.social, where we show important phenotypic divergence between online subjects who self reported high autism traits and those formally diagnosed by clinicians.
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Chris Chatham @chchatham.bsky.social · 07/02/2025
Congrats; love this. it’s so important to understand these differences, partly so as to optimally leverage & understand assortative effects. Such dynamics will grow more powerful as scientific inference is increasingly democratized & as existing health discovery institutions/initiatives are degraded
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Chris Chatham @chchatham.bsky.social · 06/02/2025
Thank you Krish and team for this incredible resource!
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