Welcome to the Future — Doing Things Just By Thinking
If you’re one of the millions who have watched Stranger Things before, you’re probably envious of Eleven’s telekinesis abilities. You may have also seen the scene where Eleven is attached to a bunch of head wires that print out her brain waves (formally known as electrograms).
Pointless but seems kinda cool right? Well of course it’s cool because it’s in a fictional show involving superpowers but what if I told you that you could understand those brain waves and be like Eleven. You can control things with your brain! Call me a liar all you want but the thing is, such technology actually exists in real life. For those in the back, let me repeat myself. You can control things with your brain! 🧠
First, let’s take a step back. How does our brain even work?
I’m glad you asked! Your brain is a very important organ that controls… everything. To do so, there are over 86 billions of cells inside called neurons that communicate with each other. Neurons are the building blocks to your brain and they are made up of four parts: dendrites, soma (body), axon, and axon terminals.
To allow the brain to communicate, the four parts of a neuron work together as follows:
- Dendrites branch from the soma and receive signals from other neurons.
- It passes the signal to the soma and if the signal is strong enough, the soma passes it to the axon. At this stage, the signal is electrical and known as an action potential.
- Then, after passing through the axon, the axon terminals “fire” the signal to the dendrite of another neuron. At this stage, the signal is chemical and known as neurotransmitters.
The process repeats and repeats as long as the dendrites of each cell receives enough “signals”. When neurons communicate, they tell each other what to do and ultimately control the entire body.
TL;DR:
Dendrites -> soma -> axon -> axon terminal -> other neuron’s dendrite
Ok cool but how does these neurons communicate to technologies? Aha. Now we’re getting to the cool stuff!
Understanding the cool stuff aka Brain Computer Interfaces
In the past couple of decades, scientists have worked hard, understanding the human brain and in the process, they managed to discover something called brain computer interfaces or BCI for short. As suggested by the name, brain computer interfaces allow the brain 🧠 to communicate with various technologies 💻.
In short, BCIs work in 3 steps:
- Collecting brain signals (similar to the ones produced by Eleven in Stranger Things)
- Interpreting the signals (translates them into understandable concepts)
- Outputting commands to a machine according to the signal (Tells machine to perform the translated version of the brain signals)
Three steps. Simple enough right?
Step 1: Collecting brain signals
When your neurons communicate, signals are being sent but if we want to control technology, we must collect and send the signals to technology.
There are many ways to collect the signals but they can broken down to three categories. Non invasive, semi-invasive, and invasive.
- Non-invasive
Non-invasive brain computer interface collects data without having to go into the brain. Most non-invasive systems use electroencephalogram or EEG signals which can be recorded from metal discs (electrodes) placed on the scalp. When the neurons communicate and send electric signals, the electrodes detect the electrical charges. The charges are amplified and appear as brainwaves on computer. EEG amplifies brainwaves using a system called differential amplifier which takes two electrode collected signals and print out the difference.
2. Semi-invasive
Semi-invasive brain computer interface collects data from the exposed surface of the brain. Most semi-invasive systems use electrocorticography or ECoG signals. The signals are collected similar to how EEG signals (using differential amlifer) are collected except crainotomy surgery is required to place sixteen electrodes on the cortex of the brain. Typically, only individuals suffering from seizures who require surgery in the first place get ECoG.
3. Invasive
Invasive brain computer interface collects data from inside the cortex of the brain. Invasive systems use intracortial signals which is obtained from implanting electrodes in the cortex. Neurosurgery must be performed to place either single unit BCIs, or multiunit BCIs into the brain. Single unit BCI detect the signal from a single area of brain cells and multiunit BCIs detect from multiple areas. The placed electrodes vary in length with some being 1.5 mm and others being 10 mm. Like the other two BCI methods, the collected signal gets sent to a computer and processed.
Wow! 🤯 Three different ways of collecting signals but why are there even three methods to begin with if they all collect the same data? Here’s the deal: BCI technology are like web browsers. They all get the same job done but each has strengths and drawbacks. Let's take a look at what’s important.
When it comes to BCI, there are 6 main things that matter: Spatial resolution, noise resistance, amplitude, temporal resolution, accessibility, and risk. Yeah, I know I just spewed a bunch of gibberish 👉👈 but hold on, let me explain.
- Spatial resolution is how precise the signal is measured. A higher spatial resolution more accurately identifies where a signal was sent.
- Noise resistance means how resistant the signal is to movements. If the signal is not noise resistant, the blink of an eye or movement of the head may alter the signal.
- Amplitude refers to the measure of a change of the signals. Higher amplitude means stronger signal.
- Temporal resolution is how close the measured activity is to the time it actually occurred. Higher temporal resolution is more reflective of the event occurence.
- Accessibility in context of BCI is how affordable and feasible the technology is. BCIs that are cheap and ready to use is much more accessible than BCIs that are expensive and require surgery.
- Risk refers to the dangers associated with the technology
Below is a table that compares BCI technologies based on the 6 important factors.
TL;DR:
- Non-invasive BCI usually collects EEG signals by placing electrodes on the top of one’s scalp. It is very affordable and accessible but it’s not the most accurate. The signals are detected through the scalp which can block off a lot of activity.
- Semi-invasive BCI usually collects ECoG signals by placing electrodes on the surface of the brain with surgery. It is less affordable and accessible but it gets more accurate signals. Since it requires surgery, most people don’t go for it unless they are already getting surgery.
- Invasive BCI collects intracortial signal by placing electrodes inside the brain. It is very costly and not accessible but it is the most accurate. However, it is quite risky since the brain may reject a foreign implant and the implant can corrode after a period of time, reducing its accuracy. It is typically only used for blind and paralyzed patients.
Step 2: Interpreting the signals
After exploring step 1 and the technologies involved to collect brain signals, how on earth do we read the signals? Fear not because it’s not too complicated!
As mentioned before, the collected brain signals get amplified and displayed as brain waves. Brain waves are fluctuating electrical voltages in the brain, measuring just a few millionths of a volt. To put things into perspective, a typical lightbulb requires 110 volts to light up so brain waves are very tiny.
There are 5 main types of brain waves with distinct meanings. The 5 types are gamma, beta, alpha, theta, and delta. Brain waves are categorized as one of the six based on their frequency which is the rate at which current changes direction per second. Every spike of the brain wave line means there was a change in direction. Frequency is measured in hertz (Hz) and 1 hertz is equal to 1 cycle per second.
In the picture below, the brain waves of are shown and categorized. Brain waves that have more spikes (ex. gamma) have higher frequencies compared to those with less spikes (ex. delta). The higher the frequency, the more concentrated the brain.
TL;DR:
- brain waves is the visual reprsentation of the electrical signals collected by BCI technology
- more spikes = higher frequency
- higher frequency = more concentrated
Step 3: Outputting Commands
Now that we know how brain signals can be collected and translated into brain waves, how do we connect it to technology? After all, the entire point is to have the brain control technology.
Code. 👩💻 This is where code comes into play. With the collected brain waves, different codes are written to classify the intention of the brain waves.
For example, if we wanted to use our brains to move a robot, we would think hard about moving the robot while wearing some sort of BCI technology. The EEG signals will be detected and then categorized as one of the 5 categories of brain waves. Then, we will write code that matches the brain wave detected to the action of moving a robot. This way, every time we think of moving the robot, the code knows that the brain waves produced = moving the robot.
To make the robot do different things, the process should be repeated for different types of thoughts. If you want the robot to move back, think about the robot moving back and code those signals to move back the robot.
As technology advances, measuring brain signals will be more precise. Eventually, every little action can be translated to a robot movement!
TL;DR:
- Detected brain waves can translate to machine actions using code.
- When a person thinks of x, the brain waves produced will correlate to the action x. Then, x will be performed every time the person thinks of x.
- Brain wave -> computer code -> machine action
Future of brain computer interfaces:
The future of brain computer interface is currently being built. Many companies, along with the government is paving way for a future where everything works with the human brain. Below are a few of the most innovative companies and what they’ve been up to.
- Neurable is levering BCI to help people better understand their brain and focus more.
- Kernel is a company working to create the next generation of brain measurement systems and make BCIs mainstream.
- Neuralink, probably the most known BCI company created by Elon Musk wants to translate a person’s thoughts into action. They want to make it so everyday actions can be performed by just thinking.
- Neuropace is a company working to make seizures a thing of the past by using BCI to detect and stop the seizure before it occurs.
Conclusion:
So. Back to Eleven in Stranger Things. Can you identify the type of BCI technology that was used to measure her brain waves?
Brain computer interface is technology that will bring the next revolution. Controlling things with our brain is no longer something in fictional films but actually real. As we start to use BCI to help solve some of the most pressing health conditions, we will soon incorporate BCI into everyday life. Get ready for the future; you’ve already gotten a sneak peak!
References:
https://study.com/learn/lesson/light-bulb-voltage-wattage.html
https://onlinelibrary.wiley.com/doi/10.1002/pssa.201900830#.Y3Fg5Cg3OVA.twitter
