Kari Hoffman
@karihoffman.bsky.social
neuroscientist @vanderbilt studying neural circuit+population rules for creating and deploying knowledge. computational neuroethology.
The apical dendrite looks great, and does wonders in a slice. What does it do in the living cortex? It depends on the cell. A causal spatial role for apical dendrites in the cortex www.biorxiv.org/content/10.6... by @anyiliu.bsky.social with @kenneth-harris.bsky.social and @fedrossi.bsky.social
Also, science needs to care about journalism too! The collapse of the US journalism industry (which is related to conspiracies and fractionation but not the only cause) is also a reason we are here.
📣New paper! How does the sleeping brain help us to integrate new experiences while managing memories from the past? For his PhD work, @sabbaspoor.bsky.social recorded hippocampal ensembles in freely moving monkeys and found something unexpected. 🧵1/n www.nature.com/articles/s41... 🧪🧠📈👩🔬#OpenAccess
Experience reorganizes content-specific memory traces in macaques - Nature Neuroscience
In macaques, old memories, relative to new ones, are supported by more stable and interconnected cell assemblies. New-biased and old-biased assemblies reactivate during overnight sleep and can sometim...
nature.com
One more nail in the coffin of the "it's just deconditioning" hypothesis. 60 days of strict bed rest ≠ #LongCOVID or #MECFS. Rob's group shows that while exercise capacity may be similarly reduced, the underlying skeletal muscle biology is VERY different. Time to move beyond outdated assumptions.
Tom Kindlon@tomkindlon.bsky.social · last wk.Rob Wüst, corresponding author of the new paper: "Skeletal muscle properties in long COVID and ME/CFS differ from those induced by bed rest" www.nature.com/articles/s41... Link to his full post www.linkedin.com/posts/rob-w%... #MEcfs #LongCovid
***New preprint from the lab*** showing “Generative replay across hippocampal-neocortical circuits”. In sleep we show spiking sequences in V1 (sensory neocortex!) that represent information that has not been directly experienced www.biorxiv.org/content/10.6... @bndu.ox.ac.uk @ndcnoxford.bsky.social
Generative replay across hippocampal-neocortical circuits
To make flexible decisions, the brain needs to make inferences between events that were not directly experienced together. In sharp-wave ripple (SWR) events, during periods of rest and sleep, spiking ...
biorxiv.org
If an action results in error, each neuron requires an individualized teaching signal that guides change in its output. This is the credit assignment problem of learning. Are there neurons in the brain that can compute such a sophisticated teaching signal? Yes. www.biorxiv.org/content/10.6...
Climbing fibers encode the gradient of a loss function for the cerebellum
Neurons in the brain are often many synapses away from motoneurons, yet if a movement results in error, each distant neuron needs a teacher that considers its specific contribution to production of th...
biorxiv.org
New paper alert from our lab! nature.com/articles/s41... We used stimuli sequences following 1/f statistical patterns—an ubiquitous statistical structure in natural stimuli—to probe predictive processing in the human brain. How does the brain predict upcoming sensory inputs based on past inputs?
Neural mechanisms of time-forward predictions for naturalistic auditory tone sequences - Nature Communications
A longstanding question is how the brain predicts complex, naturalistic sensory events and updates those predictions when expectations are violated. Using intracranial recordings, the authors show tha...
nature.com
Olivia Guest is my favorite person to follow when it comes to calling out AI hype based on a deep and thoughtful understanding of it. This point is so very important. It's ok not to know things. #FollowFriday
Olivia Guest · Ολίβια Γκεστ@olivia.science · 4w agoPlease consider not saying that some AI models or some statistical models are good, useful, beneficial, whatever else positive, in science if it's not your research area. It's ok not to know things. It's ok not to both side things. It's ok to ask colleagues who are experts.
Most people who develop #dementia don't have a family history of the disease. Interactions between vascular health, metabolism, environmental exposures, and *increasingly* pathogens also play a role. Brain aging starts decades before symptoms appear. 🧠 www.nature.com/articles/d41...
How to avoid dementia — what the science really says
Ambitious studies have been examining the protective effects of diet, exercise and socializing — with surprising results.
nature.com
I’m excited to share our latest preprint, and the main work from my PhD, on the role of the direct entorhinal input in hippocampus CA1 spatial coding. 1/9
bioRxiv Neuroscience@biorxiv-neursci.bsky.social · 4w agoThe emergence of a novel CA1 spatial map requires direct entorhinal input https://www.biorxiv.org/content/10.64898/2026.07.02.736055v1
Check out our @royalsociety.org Philosophical Transactions B theme issue, "The role of hippocampal prediction: bridging perception and memory." Thanks to all our fabulous authors, and my co-editors @peterkok.bsky.social and @mariamaly.bsky.social who dreamed it up and kept the train on the tracks.
Peter Kok@peterkok.bsky.social · 4w agoThe hippocampus sits at the interface of perception & memory, allowing us to link past, present, & future through its role in generating predictions. Excited to share this theme issue in @royalsociety.org's Philosophical Transactions B, co-edited with @barense.bsky.social & @mariamaly.bsky.social
A very personal story that I have kept to myself for four months posts tomorrow morning to HateComesToMainStreet.com. Subscribe now to get immediately notified.
Hate Comes to Main Street | Phil Williams | Substack
Examining the influence of white supremacists, neo-Nazis, Christian nationalists, and QAnon conspiracy theorists on Main Street America. Click to read Hate Comes to Main Street, by Phil Williams, a Su...
hatecomestomainstreet.com
Here is a brief overview of existing approaches to studying "real-world" navigation. Really happy to have worked on this with @hugospiers.bsky.social & @antoinecoutrot.bsky.social! arxiv.org/pdf/2603.11347
Hugo Spiers@hugospiers.bsky.social · 5mo agoNew lab preprint! Human Navigation Behaviour and Brain Dynamics in Real-world Contexts with co-authors: @pfvelasco.bsky.social and @antoinecoutrot.bsky.social arxiv.org/pdf/2603.11347
Bichan Wu (@bichanw.bsky.social) & I wrote a tutorial paper on Reduced Rank Regression (RRR) — the statistical method underlying "communication subspaces" from Semedo et al 2019 — aimed at neuroscientists. arxiv.org/abs/2512.12467
Reduced rank regression for neural communication: a tutorial for neuroscientists
Reduced rank regression (RRR) is a statistical method for finding a low-dimensional linear mapping between a set of high-dimensional inputs and outputs. In recent years, RRR has found numerous applica...
arxiv.org
let's talk in person! but fwiw I personally think that we talk about dimensionality! to me the important ideas within the neural manifold framework are: (1) manifolds reflect biological constraints, (2) capture population-wide functions/computations, (3) manifolds (may) have ontological power
🤩 + impressive answer 🧭🚕 @ 2:50 “Trust me, knowledge is power” 💀 This is my guy.
Hugo Spiers@hugospiers.bsky.social · 8mo agoThanks to @cnn.com for covering our research on London taxi drivers in their new, rather chatty, format 'Creators' Taxi driver Tom Scullion is the star of this piece. He trains others to learn the knowledge an has so many insights into that process. #neuroskyence www.youtube.com/watch?v=K7df...
Good resp to Bhattacharya, noting the agenda of The Spectator. When we rebut Trump attacks on science it’s good to talk about his agenda and the agenda backing him—he was selected for the job by donors who want to privatize federal funding and use science as a wedge issue to get votes for thr side.
Prof Gavin Yamey MD MPH@gavinyamey.bsky.social · 8mo agoTBH, this piece by Jay Bhattacharya (published in The Spectator, a nasty right wing rag) and the NIH deputy director is truly one of the most vile things I've read coming from the Trump Administration They brag about how they "cured" DEI; WTAF? thespectator.com/topic/cured-...
www.science.org/doi/10.1126/... damn this is so very clever! "... we investigated how the brain categorizes stimuli that are not linearly separable in the physical world ... The sensory manifold was ... expanded into a seven-dimensional perceptual manifold..."
From sensory to perceptual manifolds: The twist of neural geometry
The brain uses geometric twists to expand neural dimensionality, thus untangling perception from sensation.
science.org
Human multipatch L2/3 functional cell types. LFG. 🧠📈🧪
Yangfan Peng@yangfanpeng.bsky.social · 8mo ago🥳Excited to share our latest human multipatch paper, now out in @natneuro.nature.com 🧠 We studied the cellular and synaptic physiology of human L2–3 pyramidal neurons and identified subtype-specific local connectivity rules across individuals. www.nature.com/articles/s41... Join us: penglab.de
Tolerance has gone too far. Researchers should date other people, in my opinion
The Associated Press@apnews.com · 8mo agoResearchers have dated vertebrae from a massive prehistoric shark thought to have ruled the waves off northern Australia back to further in the Cretaceous period than was previously known.
Landmark paper from @srheilbronner.bsky.social and colleagues! www.cell.com/trends/neuro...
Reconstructing the human brain’s wiring diagram from axons up
The human brain’s long-range axonal connections are the scaffolding for communication across functionally distinct areas. Yet knowledge of the human brain’s wiring diagram remains limited, largely due...
cell.com
Last day to register for the 50th anniversary meeting Jan 8-11: parkcitywinterconf.org/register/ Historical perspectives from Lynn Nadel, Os Steward, Jim McClelland, and topics from synaptic plasticity to neural circuit dynamics of learning and memory systems to aging and dementia. #neuroskyence
Register – Park City Winter Conference
parkcitywinterconf.org
Kari Hoffman@karihoffman.bsky.social · 8mo ago📣Register now for the 50th Anniversary Park City Winter Conference on the Neurobiology of Learning and Memory parkcitywinterconf.org/register/ Deadline tomorrow, Friday, the 12th! Spread the word. 🧠🔬👩🔬 ➡️Top 5 reasons to attend: 1/6
Nice thread (and nice recognition for @trackingactions.bsky.social!)
Nicole Rust@nicolecrust.bsky.social · 8mo agoI regard what I/we do as impt for humanity (not vanity), and I spend a lot of time mapping out how to get to those end goals efficiently (like in this recent book). Unfortunately, I don't see paths to better treatments that don't involve animal research. press.princeton.edu/books/hardco...
We give examples for less striking number of neurons here. For different species, tasks, and brain areas, it's always the same observation: PCA overestimates the dimensionality -except for one very simple task- and this overestimate gets worse w the number of neurons www.biorxiv.org/content/10.1...
Nonlinear manifolds underlie neural population activity during behaviour
There is rich variety in the activity of single neurons recorded during behaviour. Yet, these diverse single neuron responses can be well described by relatively few patterns of neural co-modulation. ...
biorxiv.org
📣Register now for the 50th Anniversary Park City Winter Conference on the Neurobiology of Learning and Memory parkcitywinterconf.org/register/ Deadline tomorrow, Friday, the 12th! Spread the word. 🧠🔬👩🔬 ➡️Top 5 reasons to attend: 1/6
Keep in mind, we could have already advanced so much in this field if, for political reasons, mRNA vaccines were not severely attacked over the past 5 years. We are closer than ever to a cure for #MultipleSclerosis, and that involves preventing #EBV from damaging the brain.
Common virus jab could be key in fight against multiple sclerosis
The vaccine will be trialled in patients recently diagnosed with MS
independent.co.uk
🚨New publication! I am extremely happy to share this new review article in elife on #Traveling_Waves! @erc.europa.eu @upcite.bsky.social elifesciences.org/articles/106...
Traveling waves across scales: Different mechanisms but same canonical computation?
The review proposes a novel mechanistic distinction between first- and second-order traveling waves that subserves a same canonical computation by ordering neuronal processing to impose a computationa...
elifesciences.org
I wrote this last week with the news of the shutdown deal, about why we need a lot more to save US science. Comments and questions are welcome. ------------------- As a US scientist and NIH employee, I had mixed feelings about the reopening of the US government this week. 1/
