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James Vornov @jjvornov.bsky.social · Jul 17

Getting information in this way? I'll write about it next week. Plus bandwidth? Batteries? These aren't pacemakers.

James Vornov @jjvornov.bsky.social · Jul 17

Good point about accessing neurons. I mention toward the end of my peice that using surface potentials is a good a way to listen into ensembles compared to unit recording. We can't decode units because function is encoded in networks. We see this in Deep Neural Networks like our LLMs.

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James Vornov @jjvornov.bsky.social · Jul 16

But you're absolutely right that leaving patients in the hands of biotechs with life changing medicine is depending on profit. Like if Sarepta failed financially we'd have no alternative in DMD. And these rare diseases treated expensive bio drugs have seen shortages and supply disruptions.

James Vornov @jjvornov.bsky.social · Jul 15

But if an EOL pacemaker stops working, it's a medical necessity to upgrade and insurance or medicare will pay. Some do want manufacturers to warrantee and pay for this. So for these implants, if medically necessary they could be removed as medical care. If they're causing no problem, they get left.

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James Vornov @jjvornov.bsky.social · Jul 15

From the device side, we've had this issue forever with devices like cardiac pacemakers and defibrillators. They EOL these after a relatively short period of time- batteries, software updates leaving patients with a working device and no backup. If it's not causing problems, its monitored

Are Brain Computer Interfaces Really Our Future?

James Vornov @jjvornov.bsky.social · Jul 15

You raise an interesting point, but it's not new. I develop drugs and devices for biotechs for a living and this issue of providing benefit from a drug or device and then withdrawing it is a long standing ethical issue.

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James Vornov @jjvornov.bsky.social · Jul 15

Did you know that it's been more than 20 years since the first successful use of a brain computer interface to restore function to a patient with spinal cord injury? It seems our technology is finally catching up to the promise on both the computer and interface sides.

#neuroskyence

We’re making real progress providing brain computer interfaces for patients paralyzed by ALS and spinal cord injury. Less invasive approaches are looking promising.

When Models Collide: How the Brain Deals with Cognitive Dissonance

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James Vornov @jjvornov.bsky.social · Jul 2

This week my post is moving back into the brain science of personal identity, looking at cognitive dissonance. I’m trying to explore the what’s going on in the brain in everyday life.

#Neuroskyence

Our actions often conflict with our beliefs. The discomfort we feel isn’t moral failure — it’s what happens when valence systems disrupt the brain’s coherent story of personal identity.

If Purple isn’t real, then what is?

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James Vornov @jjvornov.bsky.social · Jun 24

The neuroscience tale of how purple, really magenta, is a synthetic color not found on the spectrum. We don't perceive the environment, but become aware of the brain's processing of color. I conclude, Kant was right, there is a priori knowledge. But he never realized it was neuronal.

#neuroskyence

Let’s talk epistemology. Actually, let’s have magenta and cyan bid farewell to epistemology altogether

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James Vornov @jjvornov.bsky.social · Jun 19

Can I be a little critical here? Why look at ketamine and dexmedetomidine, atypical anesthetics. Why not propofol, our standard here? And they note that at lower doses, the effect is graded. It's not unconsciousness but sedation. Lets be rigorous, please

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James Vornov @jjvornov.bsky.social · Jun 18

Something I still find mind-bending is that the fusiform circuit doesn’t “re-see” the full pattern each time; it just fires a sparse signature that acts like a pointer to the stored concept.

James Vornov @jjvornov.bsky.social · Jun 18

It looks from modern neuroscience that the meaning is right there in the patterns of perception. Not some homunculus judging and remembering. But we only get to see a glimpse of the workings in awareness of how the brain is figuring out what the world means on so little input.

James Vornov @jjvornov.bsky.social · Jun 18

Interesting to put this in context of memory? But which system. Clearly recognition is the reactivation of these patterns, but priming of many others. The red car reminds me of my red Acura of 25 years ago. Hadn't thought of that car in years. Latent patterns reactivated. But episodic memory?

Bye Bye Binding: Boosted and Redundant Maps

James Vornov @jjvornov.bsky.social · Jun 17

A change of pace post. How does the brain bind red to bicycle and blue to car when looking at a complex scene if color is extracted in one cortical area and form in another? And object recognition in yet another. Looking at Scholte and de Haan's recent review and going a bit further

#neuroskyence

The binding problem goes away not because we solved it, but because we never needed it to begin with.

The Brain Doesn’t Need a Homunculus—It Is One

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James Vornov @jjvornov.bsky.social · Jun 11

I don’t think it’s ever possible. You end up with an arbitrarily accurate model. But the map is not the territory. I’ve written about this extensively on my substack.

James Vornov @jjvornov.bsky.social · Jun 10

New post: How cortical maps, predictive models, and Searle’s Chinese Room describe a brain with no central observer. This is actually an update to a very old post on my site that gets a few search hits a month for “homunculus”. Love this 3D model.

#neuroskyence

open.substack.com/pub/jjvornov...

The mind arises from a collection of many maps, all working coherently to provide a model of the self in the environment. But it is the maps, no one is looking.

The Unity of Experience: How the free energy principle builds reality

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James Vornov @jjvornov.bsky.social · May 28

This week I delve a little deeper into the idea that our single threaded awareness is required for a real time regulator of behavior. The brain has to predict a unified, consistent model of self in the world in order to achieve goals.

#neuroskyence

open.substack.com/pub/jjvornov...

We only experience a single, stable perception at a time. How bistable viusal figures and Karl Friston’s big idea explain how we keep ourselves in an uncertain world

To this neurologist, Severence got self-identity exactly right

James Vornov @jjvornov.bsky.social · May 21

Here's my neurologist's take on the Severance show's concept of the divided self. While one couldn't literally divide the self so neatly, it's a clever assembly of the brain's abilities to divide memory and identity as seen in the clinic.

#neuroskyence

jjvornov.substack.com/p/im-a-neuro...

The basis of time-stamped memory, fractured identity, and the illusion of the unified mind.

jjvornov.substack.com

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James Vornov @jjvornov.bsky.social · May 14

I always think of the Steven Weinberg quote from Dreams of a Final Theory: "The explanatory arrows always point downward". We can work to explain the mechanisms of subjective experience by understanding neuronal activity, but it doesn't in general work to build theories upward.

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James Vornov @jjvornov.bsky.social · May 14

I think this is exactly where the mystery and wonder lies. There isn't the upstream assembly of features we thought. The features (color, context, shadow, line) bind but don't come together. Not the way I would have built it. That's why its more a mesh than pipeline

Why the simplest computer is faster than any human?

James Vornov @jjvornov.bsky.social · May 14

These discussions are generally about metaphors that can be confusing. Here, it can imply moving from one place to another. "Readout" is referencing a location to get a number, like a memory location in RAM. The lines in V1 get used to ID letters, they don't get moved and assembled into letters.

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James Vornov @jjvornov.bsky.social · May 14

It's really pretty mindboggling when you realize these areas are not processing piplines but dense meshes that work together. When you see a letter, lines stay in V1, no where else. The letter, word recognition are elsewhere, but they are peeking into V1 to see the forms. They don't leave.

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James Vornov @jjvornov.bsky.social · May 12

This week I explore the bottlenecks in human cognition. It is easy to see that the simplest computer can beat the fastest video gamer, but there’s a reason why slow, single-channel experiences of one thing at a time are the essence of awareness.

#neuroskyence
#neuroscience

The bottlenecks in our brains create awareness, meaning and coherence

jjvornov.substack.com