Reverse-Engineering Brains, One Neuron At A Time

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”!

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THP Semifinalist: fNIR Brain Imager

565281406845688681 The current research tool du jour in the field of neuroscience and psychology is the fMRI, or functional magnetic resonance imaging. It’s basically the same as the MRI machine found in any well equipped hospital, but with a key difference: it can detect very small variances in the blood oxygen levels, and thus areas of activity in the brain. Why is this important? For researchers, finding out what area of the brain is active in response to certain stimuli is a ticket to Tenure Town with stops at Publicationton and Grantville.

fMRI labs are expensive, and [Jeremy]’s submission to The Hackaday Prize is aiming to do the same thing much more cheaply, and in a way that will vastly increase the amount of research being done with this technique. How is he doing this? Using the same technology used in high-tech vein finders: infrared light.

[Jeremy]’s idea is much the same as a photoplethysmograph, better known as a pulse oximeter. Instead of relatively common LEDs, [Jeremy] is using near infrared LEDs, guided by a few papers from Cornell and Drexel that demonstrate this technique can be used to see blood oxygen concentrations in the brain.

Being based on light, this device does not penetrate deeply into the brain. For many use cases, this is fine: the motor cortex is right next to your skull, stretching from ear to ear, vision is taken care of at the back of your head, and memories are right up against your forehead. Being able to scan these areas noninvasively with a device you can wear has incredible applications from having amputees control prosthetics to controlling video game characters by just thinking about it.

[Jeremy]’s device is small, about the size of a cellphone, and uses an array of LEDs and photodiodes to assemble an image of what’s going on inside someone’s head. The image will be somewhat crude, have low resolution, and will not cover the entire brain like an fMRI can. It also doesn’t cost millions of dollars, making this one of the most scientifically disruptive entries we have for The Hackaday Prize.

You can check out [Jeremy]’s intro video below.


SpaceWrencherThe project featured in this post is a semifinalist in The Hackaday Prize. 

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