Types of Brain-Computer Interfaces and how they are going to change the world

“I know kung fu.” It’s one of the most memorable lines from the 1999 film “The Matrix.” Neo utters it after the entirety of kung fu knowledge is “uploaded” to his brain in mere seconds via a futuristic computer jacked into his skull.

Watching this scene always blew my mind. I was amazed by the possibility of downloading information directly into our brains. Unfortunately I wrote off the idea as a distant future. It seemed extremely far fetched but now, downloading information might be more possible than it seems.

But first, let’s get an understanding of what BCIs are:

Brain-Computer Interfaces

Brain-Computer Interfaces (BCIs) are collaborations between a brain and a device. Measuring brainwaves allows them to control thinks like prosthetics,wheelchairs, computers, and infinitely more. The interface enables a direct communications pathway between the brain and the object being controlled by using various tools which are measured by 3 things.

Scale measure how many neurons can be measured. Resolution measures how detailed the information in 2 different types, spatial (which neurons are firing) and temperal (when the neurons are firing). The final measure is invasiveness, which refers to whether or not surgery is needed to use the tool and if so, how extensively.

Types Of Tools Used For BCIs

Electroencephalography (EEGs)

Scale: High

Resolution: Low spatial, Medium-high temporal

Invasiveness: Non- Invasive

Electroencephalography is a non-invasive form of BCI which involves either directly attaching electrodes to the scalp or with an EEG cap. EEGs are known to have an excellent temporal resolution, but generally, have a low spatial resolution.

EEG caps measure the brains electrical activity between neurons. Electrodes are the key to measuring these charges. Electrodes are flat, metal discs which are attached to the scalp. EEG caps have many electrodes as different areas of the skull produce different electrical charges.

Electrodes are usually attached in the International 10–20 System. The system is based on the relationship between the location of an electrode and the underlying area of the brain, specifically the cerebral cortex. The “10” and “20” refer to the fact that the actual distances between adjacent electrodes are either 10% or 20% of the total front–back or right–left distance of the skull. For example, a measurement is taken across the top of the head, from the nasion to inion and can be used to determine the placement of electrodes using the 10–20 system.

EEGs measure your brainwaves, which typically can be classified as 5 different types.

• GAMMA WAVES (>32 Hz): Higher mental activity, including perception, problem solving, and consciousness
• DELTA WAVES (<4 Hz): Deep dreamless sleep, loss of body awareness
• THETA WAVES (4 -8 Hz): Deep meditation /relaxation, REM sleep
• ALPHA WAVES (8 -13 Hz): Calm relaxed yet alert state
• BETA WAVES (13 -32 Hz): Active, busy thinking, active processing , active concentration, and cognition

Electrocorticography (ECoG)

Scale: High

Resolution: Low spatial, high temporal

Invasiveness: Somewhat invasive

Electrocorticography is another form of BCIs that places electrodes under the skull, on the surface of the brain. The increased proximity to the brain compared to EEGs allows ECoGs to measure brainwaves more accurately and better distinguish the brainwaves of separate sections.

A company working with ECoGs right now is Neuralink. Neuralink is working towards connecting human brains to the cloud for humans to be able to learn faster (yes, that could neam downloading kung-fu into our brains). Neuralink is using a type of ECoGs called neural lace. Neural lace is an ultra-thin mesh that can be implanted in the skull, forming a net or lace of electrodes capable of monitoring brain function.

Local Field Potential (LFP)

Scale: Low

Resolution: Medium-low spatial, high temporal

Invasiveness: Very invasive

Local field potentials are tiny little micro electrodes. The way LFPs work is simple — you take a super thin needles with an electrode tip and stick it a few millimeters into the cortex. There it picks up the electrical charge from the surrounding neurons in a specific radius.

LFP gives you the decent spatial resolution an MRI combined with the instant temporal resolution of an ECoG. It’s arguably the best of all worlds in regards to resolution. However, it’s much worse when looked at from a scale and invasiveness viewpoint.

Unlike EEGs and ECoGs, LFP does not have enough scale , it can only tell you what’s going on inside its little radius. It’s also really invasive, as it’s actually in the brain.

A recent development is a the multielectrode array, which is that basic idea as the LFP but it’s around 100 LFPs all together, in a single area in the cortex.

The applications for BCIs are endless and they will play a vital role in our future. From healthcare, to education, to cloud sharing memories, BCIs have the ability to impacts every single field. Peter Diamandis even named BCIs as one of the “20 Metatrends for the 2020s”. He said that the “next decade will see tremendous progress in that direction, first serving those with spinal cord injuries, whereby patients will regain both sensory capacity and motor control.”

Companies are already making leaps and bounds with BCI technologies. Such as NeuroPace, a Silicon Valley based company that has developed implantable devices for the treatment of neurological disorders such as epilepsy with responsive stimulation. Similar to a pacemaker that monitors and responds to heartbeats, NeuroPaces RNS System is the world’s first and only medical device that can monitor and respond to brain activity. Elon Musk’s Neuralink aims to make devices to treat serious brain diseases in the short-term, with the eventual goal of human enhancement.

BCIs are already impacting millions of lives and in the future, they will revolutionize every single field. With these endless possibilities, BCIs are a diverse and fascinating field which can be used to treat neurological disorders, bypass spinal injuries, connect human brains to the cloud, control prosthetics, enable brain to brain communication, and a million things.