The brain uses orthogonal sub-dimensions in neural space as communication channels. This is a great new paper using Neuropixels from ~6500 neurons on 8 cortical and deep regions in mice. Simplifying the space helps a lot to understand the idea. Here is my toy model and notes:

Where's Doomscrolling in the brain? Evolved circuits in ant. cingulate & vlPFC to seek info about bad possibilities. Helped us survive resolving uncertainty. Problem? Our brains weren't made for X. News hijack this, trapping us in a compulsive loop #neuroscience #anxiety #brain

https://t.co/2QBa8A4Z4h

This can lead to the compulsive "checking, checking, checking" behavior of doomscrolling, as our brains are drawn to seek out every "worrisome tidbit" to try and understand potential threats, even if we have no power to prevent them.

The Compulsive Loop is this constant stream of new, often negative, information may trigger our brain's ancient drive to resolve uncertainty.

The "Information Age" Mismatch is that our brains "aren't well equipped to deal with the information age." We now have a "constant availability of information" (like endless social media feeds).

They identified the anterior cingulate cortex and ventrolateral prefrontal cortex as key areas involved in the choice to seek information about unwanted possibilities. These circuits weigh whether we want to know the bad news or prefer to remain ignorant.

We have a Drive to Resolve Uncertainty. Our brains are wired to seek information, even about potential negative events. This likely evolved as a survival mechanism in an uncertain world.

This research suggests doomscrolling might be driven by specific brain circuits that evolved to help us deal with uncertainty. https://t.co/EzfuAOf46f Here’s how the article explains it:

Where's Doomscrolling in the brain? Evolved circuits in ant. cingulate & vlPFC to seek info about bad possibilities. Helped us survive resolving uncertainty. Problem? Our brains weren't made for X. News hijack this, trapping us in a compulsive loop #neuroscience #anxiety #brain

Dopamine ≠ reward but turns out, also not the learning molecule we thought. If DA RPE is the emperor, this work SCREAMS it was running naked all the time. This paper got quite some attention recently. Let me explain why it is so relevant. Here is my toy model and notes:

Link to the paper: https://t.co/rUfaaXNYZm

If you like this, and think I should keep doing these every week, hit a like on the first post! It motivates me to spend 5-6 hours a week preparing each summary 😇.

Disclaimers: 1) This is a simplification from a very complex paper! Sorry if I omitted some details, it is all for clarity 😸 2) As any paper, this study has to be further REPLICATED to know if its true!

Limitations: The study used head-fixed mice, which restricts their natural movement repertoire. The findings must also be tested in more complex, non-Pavlovian tasks.

Implications for neuro: This challenges a foundational dogma about dopamine and learning. It shifts focus from abstract cognitive states to the concrete physical actions and motor vigor that DA might directly encode.

DA is an adaptive signal that switches its function in real-time. Upon reward delivery, it stops predicting force and starts predicting the *rate of licking* (Fig 9h, 9j).

Optogenetically stimulating DA neurons in place of reward was *not sufficient* for learning. Inhibiting DA neurons during the task *did not impair* learning (Fig 10b, 10i).

Changes in DA firing due to reward magnitude, probability, and omission were all explained by parallel changes in the *force* the mice exerted (Figs 4, 5).

This force-tuning was independent of reward, appearing during spontaneous movements. It even held true during an aversive air puff, proving it's not about "reward" (Fig 3e, 3h).

This is how we learned that from their results: They identified two distinct DA neuron types: "Forward" and "Backward" populations. These cells fire to drive movement in a specific direction (Fig 1e, 1h, 1k).