Have you seen any comparisons of this technique with that of electromagnetic stimulation? I suspect that each has its pluses and minuses, and ideally physicians should be able to select between them or combine them as part of a treatment:

"Neuron matters: neuromodulation with electromagnetic stimulation must consider neurons as dynamic identities"


This topic is relevant to me, but in reverse. I have a condition that is caused by a LACK of connection between some areas of the brain, instead of an excess. It's the opposite of the cause of epilepsy and many other conditions where the brain is flooded by signals.

I don't know of any treatment to fix what I have. I suspect the eventual treatment will be chemical, not something similar to ultrasound or electromagnetic.

My family and I (all of my siblings, my mother, and some of my nieces and nephews) were born with "aphantasia". We are completely cut off from voluntary recall of or the ability to generate a visualization of the senses. Ours is "total", beyond its basic definition of "the inability to form mental images of objects that are not present". So when I close my eyes, I literally see nothing. I can't recall anything I've ever seen or heard or touched or tasted or smelled, with just the exception of hearing songs (but not voices or sounds). I conceptually remember them, but the visualization can't happen.

And I can't imagine them, either. To create an image, I have to do it in Photoshop or on paper, since I literally can't "see it in my mind". While I don't have "face blindness", I don't know what anybody looks like until I see them. I typically recognize people, but could never provide any details for a "sketch artist". I don't know what pizza or chocolate tastes like (though I know I like them). I don't know what a flower looks like. I have no idea what sandpaper feels like. No clue what perfume smells like.

Tied to that, we also have SDAM (Severely Deficient Autobiographical Memory), which is a lifelong condition characterized by the inability to vividly relive past experiences from a first-person perspective. There are times in movies or TV where somebody's amnesia leaves them capable, but they can't recall their past. It's like that, but not due to an accident. We're like that from day one.

In both cases, it's not that our minds don't record everything. It's that the pipeline is cut off. The rare times I remember a dream, my dream is vivid, fully visual and with sound, and may be based on people I hadn't seen in decades. But while I might remember conceptually what happened in the dream, I can't picture any of it once I'm awake.

It isn't all bad. People with aphantasia are largely immune to PTSD. We tend to be better at engineering and inventing than other people, digging deep into topics. We are extremely overrepresented in sciences and engineering. We have fewer distractions in our work and other activities, since we are never replaying something from the past, nor fantasizing about something in our mind.

But it's a lonely, different kind of existence.

I have too many hobbies, since I can't recall scenes nor fantasize to fill my time. While I'm a fast reader (for example, I read book #6 of Harry Potter in a single evening), it's unfulfilling, since I can't fantasize about what's in the scenes, so I mainly read nonfiction. I probably enjoy seeing the movie version of a book far more than most people. For many years I had a recording studio. I compose, and I play many instruments. But in practice, I often enjoy a good rehearsal more than a performance in front of a large audience, since I don't remember enough about the big show for it to have an impact on me (I mainly remember the technical issues).

Typical of aphantasia, I work in research and engineering, specifically as a "software architect". Aphantasia often causes an intense desire to understand how everything works, since we can't just recall basic images. We need something deeper. As a youth, when the video game Mario Brothers came out, I was in junior high, and I literally re-created much of the game on my pre-Windows home computer (becoming a programmer and the beginnings of being a digital artist in the process). Due to my need to put things on paper to "make them real", I eventually became a software architect, where I'm paid to reverse engineer things, diagram them, and come up with new ways for how to do things better (or do things that are entirely new). I reverse engineer the world as a hobby (psychology, medicine, science, ...), so having a job that pays me to do that is great (other than dealing with office politics).

As for relationships, those of us with aphantasia are "in the now". My wife never needs to worry about me fantasizing about somebody else, or some impossible situation. I live in and prioritize the moment. But if I don't see you, you almost don't exist. My wife had to get used to doing lengthy video calls with me when one of us is out of town, since voice-only is far too impersonal for me.

When British psychologist Francis Galton first documented aphantasia in 1880, it turned out that most scientists in Europe at that time had aphantasia. Ed Catmull, co-founder of Pixar, has aphantasia, and found that production managers tended to have stronger visualizations than artists, because some of the artists in fact have aphantasia (while I should note that it's far more common for them to have the opposite extreme, hyperphantasia). As an example, Glen Keane, a key animator of Disney's "Little Mermaid", has aphantasia. I've seen an example of where when he's working he makes faces in a mirror as a reference for what he wants to draw, since he literally can't visualize what it will look like in his head. Aphantasia isn't a barrier, but it can definitely be inconvenient.

I have to laugh when people suggest meditation. While I have no issue in "clearing my mind" (my mind is truly a blank slate), the whole "visualize a sphere in your mind" or similar is truly impossible for me. I couldn't imagine things in my head when instructed to do so in elementary school, let alone now.

There have been cases where somebody with "acquired" aphantasia (e.g., due to trauma) has been able to cure it with ayahuasca or similar. But in my case, there isn't something to repair, it would be a signal to add. My memory feels like the equivalent of having lived every day of my life in a sensory deprivation chamber, knowing facts, but unable to recall or fantasize any of the senses. I was born this way, so any chemical treatment would be experimental at best. To the 96-98% of you who don't have aphantasia, it probably sounds bizarre that my fantasy is to be able to remember or imagine what ANYTHING looks or sounds like. My fantasy is to be able to have a fantasy.

What would be a workaround if there's no treatment for congenital aphantasia? What occurs to me is something that's a political hot topic right now. Almost twenty years ago, I was able to simulate video of real people in 3D on a computer to a disturbing level of realism. This was long before "deep fake" tools, or the simulations of long-dead actors in the movie "Rogue One". Why did I do it? It was towards the concept of creating avatars to re-create the audio/visual of somebody who isn't present, since I literally can't see or hear them in my mind. So while the Screen Actors Guild has been on strike to block the simulation of Robin Williams and other actors, in real life many of us have a need for a tool to visualize people due to our 100% lack of recall of their faces. There are big pluses, and big minuses. For me, after a loved one dies, since they are already largely erased from my mind, it's soon as if they never existed. If I could talk to a realistic simulation of that person (a "full A/V" experience), wrapped over something like ChatGPT, problem solved. But that's a huge political mess.

Personally, I would be happy to leave behind an accurate software simulation of myself for my family. Simulated people were frequently shown in the "Holodeck" in the series "Stark Trek Next Generation", demonstrating how it can be a useful tool. Just three decades later, far sooner than we could have imagined, we are reaching the point that we will soon have that software on a home computer, or even on a cellphone (how long until it's a holograph? Probably not that far...). We're crossing that bridge soon, like it or not.

I'll admit, I'm "part of the problem" (or is it "the solution"?). I wrote software for the NIMH two decades ago to help psychiatrists diagnose all types of mental conditions, and recently have been working on creating software-based rules to simulate how different types of people react and behave, and what their drives and priorities are. While only intended for sessions with a psychologist or similar, it could just as easily be used for arbitrary situations, good or bad.

I'm sorry I hit so many topics! Lots of subjects came to mind when I read this article. ;-)

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Compared to noninvasive electromagnetic stimulation, ultrasound can focus on much smaller areas and penetrate deeper into the brain.

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Thanks for writing about this so thoroughly. I found it fascinating, and wish you well.

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(Maybe a stupid comment. Not an expert. I spent some time in an adjacent area several years ago, but my memory is hazy.) I have the impression that ultrasound weakens the blood-brain barrier. There might even be a line of research where that was the whole point of it—use ultrasound to open the barrier and thus allow drugs into the brain. Anyway, IF in fact ultrasound weakens the blood-brain barrier, it makes me a bit nervous about very-long-term use in the context of mental health, BCIs, etc. Like, the blood-brain barrier has gotta be there for a good reason, right??? (Maybe people have looked into this, I never checked.)

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Yes, you remembered right, that’s one of the applications. (Ultrasound to weaken the BBB to sensitize brain tumors to chemotherapy). That would definitely be a potential risk, but possibly you could target the ultrasound to avoid major blood vessels? Or apply ultrasound only for a limited time? Diagnostic ultrasound is a similar intensity and is used on the brain sometimes so that gives something of a bound on the risk, but really I don’t know.

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This is fascinating, thanks for writing about it. The possibilities here seem incredible. I'd be interested to hear the bearish take on this though. In other words, if in 20 years this technology ended up going nowhere, what are the most likely reasons why?

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Some obvious open questions:

1.) can you actually miniaturize this enough to make it a wearable device, or will it always have a bulky box attached?

2.) is long-term administration of ultrasound sufficiently safe to be worth it?

3.) will we discover new useful applications of ultrasound, beyond the known uses for brain stimulation where ultrasound would just be a safer replacement for an electrode?

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Any worries about, ummm, unethical use?

Brain control devices are a staple of “evil tech used exclusively by villains in fiction”

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Yes, I’ll discuss that along with other risks in a later post.

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Oct 9, 2023·edited Oct 9, 2023

Also Charles Xavier. Mind control isn't a power which is _exclusively_ the domain of villains, but villains usually do predominate in fiction because the malign possibilities are eminently obvious, and the benign possibilities are usually not very flashy (e.g. in Firestarter, the father used his mind control abilities to be a more successful life coach; he would help people to quit addictions and become self-motivated and so forth).

If this comes to fruition, it will be a powerful tool (like fire or gunpowder or electricity) which has the potential to be used both for good and for evil. In practice, it will (mostly) solve some problems while at the same time it will create entirely new categories of problems (e.g. wireheading).

Also note that the most powerful form of mind control (and telepathy) already exists: it is called Language.

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