iiinova — where your digital self keeps evolving

Jordan Hamm @jordanhamm.bsky.social · 13/09/2026

Excited to have this out! The effect in part 1 was surprisingly robust, and we're looking forward to digging into it more.

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Jordan Hamm @jordanhamm.bsky.social · 13/09/2026

Adolescent depletion did change ACa synaptic density and physiology (background gamma/delta oscillations) — just not predictive processing.

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Jordan Hamm @jordanhamm.bsky.social · 13/09/2026

We were wrong. Depleting microglia during pre-adolescence, adolescence, or adulthood had minimal effects on V1 deviance detection or ACa–V1 top-down connectivity.

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Jordan Hamm @jordanhamm.bsky.social · 13/09/2026

The second part of our paper shifted to what role microglia might play. Microglia shape synaptic development, so we hypothesized they'd also be needed for adolescent maturation of visual cortical processing.

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Jordan Hamm @jordanhamm.bsky.social · 13/09/2026

hat could explain why we didn't see deviance detection in V1 until adulthood in mice in our paper. Still needs more testing, and we don't yet know the mechanism.

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Jordan Hamm @jordanhamm.bsky.social · 13/09/2026

But P3a gets faster through adolescence, while vMMN (an earlier index of deviance detection) gets stronger and earlier. One hypothesis is that the brain's predictive filter for vision moves "upstream" to lower processing levels as we become adults.

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Jordan Hamm @jordanhamm.bsky.social · 13/09/2026

There's some precedent in human work. Kids can obviously recognize visual novelty, and an EEG marker of deviance detection (P3a) is present in children.

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Jordan Hamm @jordanhamm.bsky.social · 13/09/2026

This emergence coincided with an adolescent-period increase in top-down functional connectivity between a higher brain region (ACa) and V1.

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Jordan Hamm @jordanhamm.bsky.social · 13/09/2026

It wasn't. In primary visual cortex (V1), neural "mismatch" responses (deviance detection) were absent at P28, and only started emerging around P56 — late adolescence in mice.

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Jordan Hamm @jordanhamm.bsky.social · 13/09/2026

Vision is thought to develop early — stereopsis, acuity, and V1 feature selectivity are in place by early childhood (and by P28 in mice). So we expected predictive processing in visual cortex to be mature early too.

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Jordan Hamm @jordanhamm.bsky.social · 13/09/2026

It has two parts: (1) a new observation about adolescent brain development, and (2) a negative result on the developmental role of microglia.

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Reposted by Jordan Hamm

bioRxiv Neuroscience @biorxiv-neursci.bsky.social · 27/08/2026

A dominant frontoparietal beta oscillatory brain state in the days after psilocybin and 5-MeO-DMT www.biorxiv.org/content/10.64898/20…

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Jordan Hamm @jordanhamm.bsky.social · 27/08/2026

Although the exact behavioral or functional correlates of this finding are open to interpretation, beta oscillations, especially in cortical networks, have been hypothesized to reflect top-down modulation, which is consistent with theories of relaxed priors in hierarchical brain networks.

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Jordan Hamm @jordanhamm.bsky.social · 27/08/2026

We found a beta-band (15-25Hz) right frontoparietal network that was over-represented in the resting state in individuals who had recently taken psychedelics, primarily in the first week after the dose.

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Jordan Hamm @jordanhamm.bsky.social · 27/08/2026

Each state consisted of a distinct spatial topography and frequency band and were highly consistent across subjects/groups.

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Jordan Hamm @jordanhamm.bsky.social · 27/08/2026

We compared individuals who had recently taken psilocybin, LSD, or 5-MeO-DMT and analysed the resting state in a somewhat unconventional way. Instead of just comparing average power or inter-electrode phase-locking/correlations, we parceled the data into semi-stable states.

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Jordan Hamm @jordanhamm.bsky.social · 02/04/2026

Anna has accepted at job at SURA in DC as a senior policy advisor. I feel honored to have worked with her. sura.org I don’t think I can overstate her potential.  For those of you who don't know Dr. Rader Groves, I don't really know where to begin... but imagine if Leslie Knope was a scientist.

sura.org

SURA (Southeastern Universities Research Association)

SURA enables the advancement of Big Science, large scale leading-edge research, and industry innovations.

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Jordan Hamm @jordanhamm.bsky.social · 02/04/2026

This year, she wrapped up her two studies (one linking genes to dendrite loss and mismatch responses; one focused on the development of mismatch responses in adolescence) which are preprints and currently under review. www.biorxiv.org/content/10.1... and … . www.biorxiv.org/content/10.6...

biorxiv.org

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Jordan Hamm @jordanhamm.bsky.social · 02/04/2026

Anna joined my lab at the peak of covid, but quickly gathered data, coauthored key publications, and wrote a book chapter. On her first F31 submission, she scored a 2nd percentile (which was subsequently awarded).

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Jordan Hamm @jordanhamm.bsky.social · 02/04/2026

Huge congrats to my grad student, Dr. Anna Rader Groves, who successfully defended her disseratation last week! I consider myself lucky to have mentored Anna over the past 5 years.

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Jordan Hamm @jordanhamm.bsky.social · 29/01/2026

Both dendrite loss and reduced mismatch negativity are pronounced in numerous neuropsychiatric disorders. Correlating these observations in patient samples only gets us so far. Animal models provide a controlled system to understand how distinct features causally connect.

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Jordan Hamm @jordanhamm.bsky.social · 29/01/2026

Although this particular variant may only explain a fraction of human pathologogy, its downstream impacts on neuronal structure via RhoA-GEF make it a useful system for connecting convergent molecular, structural, and functional phenotypes.

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Jordan Hamm @jordanhamm.bsky.social · 29/01/2026

A little background: KalrnPT is a rare variant affiecting the kal-9 isoform of kalirin — a key regulator of dendrite and spine morphology via the Rac and RhoA.

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Jordan Hamm @jordanhamm.bsky.social · 29/01/2026

This occurred against a backdrop of normal feature selectivity and firing rates in V1, as well as unaffected dendritic structure in other layers of V1.

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Jordan Hamm @jordanhamm.bsky.social · 29/01/2026

We report co-occurring dendrite loss and sensory integration (visual mismatch responses) specific to supragranular (layer 2/3) neurons in visual cortex due to a missense mutation affecting Kalirin (KalPT) -- and specifically, the kal9 isoform.

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Jordan Hamm @jordanhamm.bsky.social · 29/01/2026

Excited to share our preprint! Impressive effort from grad student Anna Rader Groves and co-author @cgalli-io.bsky.social, in collaboration with Melanie Grubisha and Robert Sweet (PITT). @grubisha

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Jordan Hamm @jordanhamm.bsky.social · 08/01/2026

However, when the predictable "B" was replaced with a locally redundant "A" (AAAA-A), mouse V1 responses were attenuated. This suggests that V1 is modulated by higher-order context, but when certain features are highly adapted, this stimulus-specific adaptation masks global deviance detection.

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Jordan Hamm @jordanhamm.bsky.social · 08/01/2026

We trained mice on simple sequences of AAAA-B. After just 10 repeats, mice modulated their V1 response gain to the predictable "B" stimulus. When we replaced the B with a C, mouse V1 responded strongly (i.e. global "deviance detection"). 2/3

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Jordan Hamm @jordanhamm.bsky.social · 08/01/2026

Excited to share our preprint! We show that primary visual cortex is modulated by global predictability. This effect depended on higher level brain region (area ACa), and better explained classic oddball paradigms better than “local” context effects (i.e., recent stimulus history). 1/3

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Reposted by Jordan Hamm

Adam Hockley @adhockley.bsky.social · 07/01/2026

Our new preprint is out! We show that deviance detection in auditory cortex conveys the theorised comparison of internal prediction to sensory input. Our data confirm this key assumtion that links theoretical models of sensory processing to experimental data. www.biorxiv.org/content/10.6...

biorxiv.org

Cortical deviance detection represents a canonical difference signal

Context modulates neural processing of sensory stimuli. Neural responses are suppressed to stimuli that are typical in their context and augmented to stimuli that deviate from their context. The latte...

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Reposted by Jordan Hamm

bioRxiv Neuroscience @biorxiv-neursci.bsky.social · 19/08/2025

Visuomotor mismatch EEG responses in occipital cortex of freely moving human subjects www.biorxiv.org/content/10.1101/202…

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Reposted by Jordan Hamm

Sofiya Hupalo @sofiyahupalo.bsky.social · 12/08/2025

Just learned that my @acnporg.bsky.social panel was accepted! With my colleagues Zoë Hughes, @jordanhamm.bsky.social, Bryan Baxter & Patricio O'Donnell, our #ACNP2026 panel will highlight cross-species approaches using functional brain-based biomarkers to address translational gaps in psychiatry

media.tenor.com

a group of people jumping off a cliff into a body of water with a caption that says colnah.cy

Alt: people jumping off a cliff into a body of water

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Jordan Hamm @jordanhamm.bsky.social · 05/08/2025

First lab outing since the move to NYC.... feeling so lucky to have such a talented and fun group! with Lital Rachmany, @adhockley.bsky.social, me, Molly Hornick, Fumiyasu Imai, and @cgalli-io.bsky.social

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Jordan Hamm @jordanhamm.bsky.social · 21/05/2025

Paper forthcoming. Thankfully, I’ve managed to keep him in my lab as a Research Scientist at the Nathan Kline Institute and NYU.

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Jordan Hamm @jordanhamm.bsky.social · 21/05/2025

and designed beautiful intuitive figures. For his final project, Connor wasn't afraid to dig into a well-worn topic in neuropsychiatry — how and why NMDA-receptor antagonists exert such powerful yet nuanced effects on brain dynamics, perception, and cognition— and he was able to glean new insights!

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Jordan Hamm @jordanhamm.bsky.social · 21/05/2025

In his time as a graduate student, Connor excelled at every aspect of research. He set up complex equipment, conducted extremely high quality recordings, analysed data in thoughtful and creative ways, applied rigorous statistics, wrote engaging introductions and balanced discussions, ...

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Jordan Hamm @jordanhamm.bsky.social · 21/05/2025

I’m delighted to congratulate Dr. Connor Gallimore for successfully defending his dissertation, “Patterns of laminar engagement during visual mismatch processing”. I consider myself lucky that Connor joined my lab in 2019. His CV, though impressive on its own, doesn’t even scratch the surface.

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Jordan Hamm @jordanhamm.bsky.social · 13/04/2025

Beautiful views and stimulating science discussion this week at University of Zurich/ETH Zurich with Wolfger von der Berhens, Fatih Yanık and many others. Honored to share my work with such a world class group!

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Jordan Hamm @jordanhamm.bsky.social · 27/02/2025

I'm hiring a full-time research technician to work in my lab at Nathan Kline. Benefits included! Some lab experience preferred... experience with mouse surgeries a huge plus. If you live in NYC, there are two daily shuttles that take ≈20 min from upper manhattan. nki.applicantpro.com/jobs/3663631

nki.applicantpro.com

Research Technician I (Emotional Brain Institute) (210-2025-06) - Orangeburg, NY

JOB DESCRIPTION: The Emotional Brain Institute (EBI) is a multidisciplinary institute aimed at addressing fundamental questions in neuroscience and neuropsychiatry. We seek to hire a research technici...

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Jordan Hamm @jordanhamm.bsky.social · 16/02/2025

Combined with that recent paper on cell-wise expression of SZ GWAS hits ( doi.org/10.1038/s415... ), this is telling me that translational studies of basic disease mechanisms in schizophrenia need not be limited to -- or even focused on -- prefrontal cortex....

doi.org

Mapping the cellular etiology of schizophrenia and complex brain phenotypes - Nature Neuroscience

Duncan and colleagues link specific human brain cell types to schizophrenia and other complex brain phenotypes, providing mechanistic insights and a cellular taxonomy for psychiatric disorders.

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Jordan Hamm @jordanhamm.bsky.social · 16/02/2025

New results from study of cortical thickness in 1211 psychosis cases and 734 controls demonstrates that "visual cortex is among the most profoundly affected brain regions", with effect sizes larger than prefrontal regions. www.medrxiv.org/content/10.1...

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Reposted by Jordan Hamm

Rafael Yuste @rafaelyuste.bsky.social · 10/02/2025

Press release of our new article in Neuron: How Does the Brain Differentiate New Stimuli From Old Ones? | Columbia News news.columbia.edu/news/how-doe...

news.columbia.edu

How Does the Brain Differentiate New Stimuli From Old Ones?

A study sheds light on how networks in the brain detect new information, offering insight into disorders like schizophrenia.

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Jordan Hamm @jordanhamm.bsky.social · 10/02/2025

Stimulus features and stimulus context are distinctly represented across populations in both primary and higher order auditory areas. Through computational modeling, we demonstrate that context and stimulus history may be encoded in ongoing activity in recurrent networks. 2/2

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