Kari Hoffman

📣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

📣Say it louder for the labs in the back.

United States: Amid funding uncertainty, neuroscientists report a mix of cynicism, persistence www.thetransmitter.org/funding/amid... by @emilysingerneuro.bsky.social with @nicolecrust.bsky.social @sharenarice.bsky.social

🔄 Uno reverse alert, PFC-HPC folks! This throws a spanner in the works of the simple “reuniens as relay” to hippocampus! 🏅Well crafted study. (Shoutout to my student @noahwillhite.bsky.social for tipping me off to it)

Excited to share our lab's recent paper showing that direct electrical stimulation of the human amygdala enhances recognition memory for objects but not scenes. The article is open-access, and we'd love to hear your thoughts! Please share! TY to everyone involved! www.nature.com/articles/s42...

🙌 ❤️🔥Yes to all the things. The 1st and 4th points may be related. Less about minimizing a reward error term and more about maximizing efficiency, allostasis.

New paper from the BCM Neurosurgery research team! "Neural basis of compositional control" led by @assiachericoni.bsky.social and @justfineneuro.bsky.social ! 🧵 www.nature.com/articles/s41...

There is nothing either good or bad, but joking makes it so - Bob untucks humor #bb28

Can’t overstate this:

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

G-wiz

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.

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 Time to move beyond outdated assumptions.

***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

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...

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?

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

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...

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

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.

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.

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

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

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.

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.

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..."

Human multipatch L2/3 functional cell types. LFG. 🧠📈🧪

Tolerance has gone too far. Researchers should date other people, in my opinion

Landmark paper from @srheilbronner.bsky.social and colleagues! www.cell.com/trends/neuro...

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

Nice thread (and nice recognition for @trackingactions.bsky.social!)

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...