Eyes are windows into the soul, the old saying goes. They are also pathways into the mind, as much of our brain is involved in processing visual input. This dedication to vision is partly why much of AI research is likewise focused on machine vision. But do artificial neural networks (ANN) actually work like the gray matter that inspired them? A recently published research paper (DOI: 10.1126/science.aav9436) builds a convincing argument for “yes”.
Neural nets were named because their organization was inspired by biological neurons in the brain. But as we learned more and more about how biological neurons worked, we also discovered artificial neurons aren’t very faithful digital copies of the original. This cast doubt whether machine vision neural nets actually function like their natural inspiration, or if they worked in an entirely different way.
This experiment took a trained machine vision network and analyzed its internals. Armed with this knowledge, images were created and tailored for the purpose of triggering high activity in specific neurons. These responses were far stronger than what occurs when processing normal visual input. These tailored images were then shown to three macaque monkeys fitted with electrodes monitoring their neuron activity, which picked up similarly strong neural responses atypical of normal vision.
Manipulating neural activity beyond their normal operating range via tailored imagery is the Hollywood portrayal of mind control, but we’re not at risk of input injection attacks on our brains. This data point gives machine learning researchers confidence their work still has relevance to biological source material, and neuroscientists are excited about the possibility of exploring brain functions without invasive surgical implants. Artificial neural networks could end up help us better understand what happens inside our brain, bringing the process full circle.
[via Science News]
Can you electronically enhance your brain? I’m not talking about surgically turning into a Borg. But are there electronic methods that can improve various functions of your brain? Fans of brainwave entrainment say yes.
There was an old recruiting ad for electrical engineers that started with the headline: The best electronic brains are still human. While it is true that even a toddler can do things our best computers struggle with, it is easy to feel a little inadequate compared to some of our modern electronic brains. Then again, your brain is an electronic device of sorts. While we don’t understand everything about how it works, there are definitely electric signals going between neurons. And where there are electric signals there are ways to measure them.
The tool for measuring electric signals in the brain is an EEG (electroencephalograph). While you can’t use an EEG to read your mind, exactly, it can tell you some pretty interesting information, such as when you are relaxed or concentrating. At its most basic we’ve seen toys and simple hobby projects that purport to be “mind controlled” but only at an incredibly rudimentary level.
Brainwave entrainment is a hypothesis that sending low frequency waves to your brain can give your mind a nudge and sync up brain activity with the equipment measuring it. The ability to synchronize with the brain could yield much better measurements for a meaningful interface between modern electronics and electric storm of thought happening in your head.
Continue reading “Brain Hacking With Entrainment”
Kahn — perhaps Star Trek’s best-hated villain — said: “Improve a mechanical device and you may double productivity, but improve man and you gain a thousandfold.” In fact, a lot of hacking effort goes into doing just that. Your phone has become an extension of your memory, for example. We use glasses, cameras, and hearing aids to shore up failing senses or even give us better senses than normal. But hacking your body — or someone else’s — has always been controversial. While putting an RFID chip in your finger is one thing, would you consider having a part of your brain removed? That sounds crazy, but apparently, there is a growing interest in having your amygdala removed.
To be clear: we think this is a terrible idea. The science is shaky, at best, and we certainly wouldn’t want to be among the first to try something so radical. But why is anyone even talking about it?
The amygdala is part of your brain that causes at least some of your fear and anxiety. Get rid of your amygdala, get rid of anxiety? What’s even stranger is this the procedure — an amygdalectomy — has been going on since the 1960s! Injections of oil and wax destroy the tissue and this treatment is used for some forms of epilepsy and to manage certain aggressive behavior problems in mentally ill patients. In modern times, the procedure is not very common although it appears that it does still occur in some places. But the technology to do it does exist. There have also been documented cases where people lose their amygdala from natural causes that gives us some clues of what life would be like without one.
However, it is hard to say if these people lost fear. Most of the surgical patients were already suffering from a variety of problems. There is some evidence that the naturally occurring amygdalaless patients experienced less fear in some situations, but may experience more fear in others. They also may have other problems such as difficulty understanding social cues or making eye contact. We’re not 100% sure what the amygdala does, even disregarding potential side effects.
Continue reading “Ask Hackaday: What Are Your Less Extreme Brain Hacks?”
Neural networks use electronic analogs of the neurons in our brains. But it doesn’t seem likely that just making enough electronic neurons would create a human-brain-like thinking machine. Consider that animal brains are sometimes larger than ours — a sperm whale’s brain weighs 17 pounds — yet we don’t think they are as smart as humans or even dogs who have a much smaller brain. MIT researchers have discovered differences between human brain cells and animal ones that might help clear up some of that mystery. You can see a video about the work they’ve done below.
Neurons have long finger-like structures known as dendrites. These act like comparators, taking input from other neurons and firing if the inputs exceed a threshold. Like any kind of conductor, the longer the dendrite, the weaker the signal. Naively, this seems bad for humans. To understand why, consider a rat. A rat’s cortex has six layers, just like ours. However, whereas the rat’s brain is tiny and 30% cortex, our brains are much larger and 75% cortex. So a dendrite reaching from layer 5 to layer 1 has to be much longer than the analogous neuron in the rat’s brain.
These longer dendrites do lead to more loss in human brains and the MIT study confirmed this by using human brain cells — healthy ones removed to get access to diseased brain cells during surgery. The researchers think that this greater loss, however, is actually a benefit to humans because it helps isolate neurons from other neurons leading to increased computing capability of a single neuron. One of the researchers called this “electrical compartmentalization.” Dig into the conclusions found in the research paper.
We couldn’t help but wonder if this research would offer new insights into neural network computing. We already use numeric weights to simulate dendrite threshold action, so presumably learning algorithms are making weaker links if that helps. However, maybe something to take away from this is that less interaction between neurons and groups of neurons may be more helpful than more interaction.
Watching them probe neurons under the microscope reminded us of probing on an IC die. There’s a close tie between understanding the brain and building better machines so we try to keep an eye on the research going on in that area.
Continue reading “Brain Cell Electronics Explains Wetware Computing Power”
When auditory cells are modified to receive light, do you see sound, or hear light? To some trained gerbils at University Medical Center Göttingen, Germany under the care of [Tobias Moser], the question is moot. The gerbils were instructed to move to a different part of their cage when administrators played a sound, and when cochlear lights were activated on their modified cells, the gerbils obeyed their conditioning and went where they were supposed to go.
In the linked article, there is software which allows you to simulate what it is like to hear through a cochlear implant, or you can check out the video below the break which is not related to the article. Either way, improvements to the technology are welcome, and according to [Tobias]: “Optical stimulation may be the breakthrough to increase frequency resolution, and continue improving the cochlear implant”. The first cochlear implant was installed in 1964 so it has long history and a solid future.
This is not the only method for improving cochlear implants, and some don’t require any modified cells, but [Tobias] explained his reasoning. “I essentially took the harder route with optogenetics because it has a mechanism I understand,” and if that does not sound like so many hackers who reach for the tools they are familiar with, we don’t know what does. Revel in your Arduinos, 555 timers, transistors, or optogenetically modified cells, and know that your choice of tool is as powerful as the wielder.
Optogenetics could become a hot ticket at bio maker spaces. We have talked about optogenetics in lab rodents before, but it also finds purchase in zebrafish and roundworm.
Continue reading “Shining A Light On Hearing Loss”
Most posts here are electrical or mechanical, with a few scattered hacks from other fields. Those who also keep up with advances in biomedical research may have noticed certain areas are starting to parallel the electronics we know. [Dr. Rajib Shubert] is in one such field, and picked up on the commonality as well. He thought it’d be interesting to bridge the two worlds by explaining his research using analogies familiar to the Hackaday audience. (Video also embedded below.)
He laid the foundation with a little background, establishing that we’ve been able to see individual static neurons for a while via microscope slides and such, and we’ve been able to see activity of the whole living brain via functional MRI. These methods gradually improved our understanding of neurons, and advances within the past few years have reached an intersection of those two points: [Dr. Shubert] and colleagues now have tools to peer inside a functional brain, teasing out how it works one neuron at a time.
[Dr. Shubert]’s talk makes analogies to electronics hardware, but we can also make a software analogy treating the brain as a highly optimized (and/or obfuscated) piece of code. Virus stamping a single cell under this analogy is like isolating a single function, seeing who calls it, and who it calls. This pairs well with optogenetics techniques, which can be seen as like modifying a function to see how it affects results in real time. It certainly puts a different meaning on the phrase “working with live code”!
Continue reading “Reverse-Engineering Brains, One Neuron At A Time”
Cryonics — freezing humans for later revival — has been a staple of science fiction for ages. Maybe you want to be cured of something presently incurable or you just want to see the future. Of course, ignoring the problem of why anyone wants to thaw out a 500-year-old person, no one has a proven technology for thawing out one of these corpsicles. You are essentially betting that science will figure that out sometime before your freezer breaks down. A new startup called Nectome funded by Y Combinator wants to change your thinking about preservation. Instead of freezing they will pump you full of preservatives that preserve your brain including fine structures that scientists currently believe contain your memories.
Nectome’s strategy isn’t to have you revived like in conventional cryonics. They think the technology to do high definition scans of your preserved brain will exist soon. Those scans might allow future scientists to recreate your brain in a simulation. That isn’t really the same as coming back to life, though. At least we don’t imagine it is.
Continue reading “Are You Dying To Upload Your Brain?”