Christos Constantinidis

Aurora over Swedish Forest

apod.nasa.gov/apod/ap22032...

👇New biosketch requirement update.

“After evaluating the number and types of recent technical inquiries we received to both the SciENcv and eRA Service Desks, we recognize the difficulties these issues have had on the community’s ability to comply with the original timeline of January 25, 2026.”
👇

House and Senate appropriators endorse NIH budget increase, reject Trump’s proposed cuts Congressional appropriations committees offered a near-total rebuke of President Trump’s proposed downsizing and reshaping of the NIH.

Congress toyed with the idea of explicitly prohibiting multi-year funding of NIH grants - which severely cut down the number of awards last year - but in the end, it didn't go through. Expect paylines to be only moderately better this year.

www.statnews.com/2026/01/20/n...

FY 2026 R&D Appropriations Dashboard | American Association for the Advancement of Science (AAAS)

NIH receives a 0.9% increase in the appropriation bill the House and Senate voted that now awaits the President's signature. Below inflation - but better than the 40% decrease the President's budget requested.

www.aaas.org/news/fy-2026...

gutterballing

super surveillance

hedgehogging

obsessing over tiny predictors

I've been on the internet since the 90s and this remains one of the very best things I've encountered here. Thanks @mastroianni.bsky.social for all your writing but especially this, you beautiful bouncing baby bog boy. "So you wanna de-bog yourself" www.experimental-history.com/p/so-you-wan...

It won't actually exist for another month or so, but because it now 'exists' on amazon, I'll humbly observe that, after working through this book, your student/trainee would be able to read and understand all but two or three papers in this week's J. Neurosci. Check it out:

Repeatable, low-drift recordings in behaving non-human primates using flexible microelectrodes

www.biorxiv.org/content/10.6...

Our results provide a critical confirmation of the Standard Model of Working memory.

Many thanks to my students who did these challenging experiments, and particularly the co-first authors, Rana Mozumder and Zhengyang Wang (end)

Had persistent activity truly been an artifact, the existence of gaps and off-states would have greatly degraded the performance of simultaneous populations during the delay period (14/10)

Furthermore, this decrease was present in all task epochs, including the stimulus presentation and response periods, rather than the delay period alone. We speculate that off states are caused by variations in neuromodulatory tone (13/10)

When we calculated decoding accuracy of populations of neurons sampled from different trials (or “pseudo-populations”, commonly used in neurophysiology) and tested them with neurons recorded simultaneously, only a subtle performance decrease was evident (12/10)

However, we also show that such off-states are relative decreases in firing rate rather than absolute “gaps” in spiking. Activity across the network continued to maintain information about the stimulus being remembered even during off states (11/10)

Intermittent rate coding and cue-specific ensembles support working memory - Nature By recording large populations of neurons in behaving monkeys using newly developed silicon probes, we show that intermittent periods of memorandum-specific spiking coexist with synaptic mechanis...

A recent study has revealed off-states in the activity of prefrontal neurons during working memory (nature.com/articles/s41...) . We replicated this finding and additionally show that such off-states are coordinated across the prefrontal and posterior parietal cortex (10/10)

Such persistence is only evident for stimuli that are optimal for the recording site. Picking a suboptimal stimulus will not produce such asynchronously elevated firing, which is not an argument that persistent activity is not present somewhere else in the PFC (9/10)

In this article we document “The Asynchronous State” of Working Memory. In single trials, individual neurons may not exhibit persistent activity, however populations of ~100 neurons are sufficient to generate activity elevated above the baseline for the entire delay period (8/10)

However empirical validation was lacking until now.

Enter modern neurophysiological techniques, e.g. Neuropixel recordings from primates (7/10)

Persistent Spiking Activity Underlies Working Memory Persistent activity generated in the PFC during the delay period of working memory tasks represents information about stimuli held in memory and determines working memory performance. Alternative mode...

We have argued that persistent activity does not imply a perfectly regular firing rate at the level of single neurons. The collective activity of multiple neurons is what maintains information. See this review for a more detailed explanation: www.jneurosci.org/content/38/3...

Alternative theories have sprung out, instead, suggesting that “activity-silent” mechanisms allow information to persist over periods when firing ceases (5/10)

This has led to the idea that observed persistent activity is an “artifact of averaging”: it only becomes evident when firing rate from multiple trials is averaged together, creating a mere illusion of persistence (4/10)

A thorn in the side of this theory, however, has been that the firing of cortical neurons is quite irregular; individual neurons rarely exhibit continuous, uninterrupted firing throughout the entire delay period of working memory tasks (3/10)

The neural basis of working memory has been debated. What we like to call “The Standard Model” of working memory posits that persistent discharges generated by neurons in the prefrontal cortex constitute the neural correlate of working memory (2/10)

Asynchronous firing and off states in working memory maintenance Persistent spiking activity and activity-silent mechanisms have been proposed as neural correlates of working memory. To determine their relative cont…

New paper from the lab: "Asynchronous firing and off states in working memory maintenance"

www.sciencedirect.com/science/arti...

a beer can named action potential with an action potential drawn on it

made a trip to Cerebral Brewing which has perhaps the best named beer for a neuroscientist #neuroskyence

🔬 We're hiring a Junior Group Leader for Data-Driven Digital Twins/System Models in medicine/life sciences at @uni_goettingen! Perfect opportunity for early-career researchers who want to:
- Lead their own research group
- Work at the intersection of AI, simulation, and biomedicine

Congratulations

It looks like Congress has little appetite for continuing the DOGE capping of indirect-costs fight

Some funding good news for a change (from AAAS policy alert)

The House and Senate released a final version of the National Defense Authorization Act. Of importance to the research community, the bill prohibits the DOD from imposing a 15% cap on indirect costs to institutions of higher education.

For you NIH folks, two interesting announcements. 1) no more LOIs. 2) No more needing permission to apply with a budget of over $500K per year. grants.nih.gov/grants/guide...

How distributed is the brain-wide network that is recruited for cognition? - Nature Reviews Neuroscience Both localized and distributed views on the functional organization of the brain have been put forward. In this Perspective, Rosen and Freedman examine the degree to which these two views account for ...

Thoughtful review with some good recent historical perspective on the ongoing paradigm shift that is radically changing the way we think about what brain areas do.

www.nature.com/articles/s41...

Sensory reformatting for a working visual memory A core function of visual working memory (WM) is to sustain mental representations of recent visual inputs, thereby bridging moments of experience. This is thought to occur in part by recruiting early...

new paper in TICS officially out today. great learning from and writing with Anastasia, and super cool cover art from Prof. Pinar Yoldas.
www.cell.com/trends/cogni...