Guide: barabasi.me/fellowships/

List: docs.google.com/spreadsheets...

As always, DM or email with any questions!

Breast Cancer:
nature.com/articles/d41...

Pregnancy and the Brain:
nature.com/articles/d41...

X Chromosome and the Brain:
www.nature.com/articles/d41...

Guide: barabasi.me/fellowships/
Fellowships: docs.google.com/spreadsheets...

Please DM me with fellowships I should add!

So while certain elements can be reused, and indeed on different timescales, in many cases the System Two learning is a quick realization, which can be seen in the neural dynamics, where System Three places the knowledge into the animal's repertoire through more extensive synaptic rewiring.

Thanks for sharing!

I distinguish System Two and System Three as follows:

System Two, the Eureka Moment, can be implemented dynamically, e.g. a shift in attractor state, with a sprinkle of STDP.

But then System Three exists to "deepen the well", like with hippocampal replay.

Encountering a paywall?

Read for free at this link: rdcu.be/ea4rd

Takeaways:
• Most innate circuits (System One) are pre-coded genetically.
• “Learning” (System Two) can be shockingly rare but potent when it happens.
• Ongoing plasticity (System Three) is mostly to stabilize or fine-tune your existing wiring.

But why do we think we learn?
• Human babies are born relatively immature → System One finishes outside the womb.
• Language/semantic memory makes us feel like everything is learned.
• AI hype around “learning from scratch” feeds the misconception that all brains do the same.

In this vein, we separate circuit formation into three “systems,” each deployed at different times and contexts:
• System One: Developmental Maturation
• System Two: Eureka Moments
• System Three: Staying Tuned

We resolve this nature–nurture conflict by proposing that:

(1) Critical knowledge for engaging the world is realized by development,

(2) Novel information isn’t strictly required for daily competence, and

(3) Plasticity mainly provides homeostatic feedback stabilization.

However, this view conflicts with innate behaviors.

Many animals perform intricate problem-solving immediately after birth—well before experience could shape their connections (see our previous work: x.com/bdanubius/st...).

So how can circuits function so effectively so soon?

Dogmatically, circuits assembly has been split into two phases:

(1) predetermined, genetically driven coarse wiring of the nervous system.

(2) pruning and refinement through interactions with the environment, which is thought to fine-tune mission-critical neural connectivity.

🔥🔥🔥 Efficiency, resiliency tradeoff + behavioral reconfiguration of circuits provide clean interpretations of the multi-scale structure of brain activity 🔥🔥🔥