2 Brain-Computer Interfaces (BCI)

Welcome to the second day of the Virtual REACH Program! Yesterday you explored the basics of neuroscience and neural engineering. Over the next two days we will focus on different types of neurotechnologies in order to understand how they work and how they are transforming the lives of people with and injuries. Today we will explore how and why researchers are working to connect the human brain with computers and machines.  These neurotechnologies are known as or brain-machine interfaces (BMIs). In today’s virtual session, Dr. Rajesh Rao (a computer scientist and co-director of the CNT) will share his cutting-edge research.

Stop for a minute and think to yourself:

  • Why would we want to connect a brain to a computer or a machine?
  • What might be the benefits?
  • What might be the challenges, problems, or unintended consequences when we connect the human brain with technology?

 

Try It!

Respond to this question on a Padlet:

  • What might be the challenges, problems, or unintended consequences when we connect the human brain with technology?

Post a brief response to this Considerations for BCI Technology Padlet. See what other VRP participants have posted as well. You can “favorite” the ones you agree with or add comments.

Then, hit the “back” arrow on your web browser to return to this chapter and keep reading.

 

Part 1: What is a Brain-Computer Interface?

We will launch today’s exploration of brain-computer interfaces with a video from the BrainWorks series from UW TV in which Dr. Eric Chudler and a group of teens explore how BCIs work. This video is 27 minutes long, so grab a cup of tea and hit play.  English captions are available.

 

Reflect on What You Learned

After watching the video, check your knowledge with a short quiz.

 

How do BCIs work?

A brain-computer interface can help a person use their neural signals to control a wheelchair, computer cursor, prosthetic limb, or other device. Image credit: Frontiers for Young Minds.

 

Let’s dig in a little deeper to understand how BCIs work. Read the article, “Brain-Machine Interfaces: Your Brain in Action”, which provides an overview of how BCIs/BMIs work, and in particular, how they use generated by the body to communicate with computers and machines.

 

Read This!

Read the article: “Brain-Machine Interfaces: Your Brain in Action.” As you read, consider the three major challenges of BCIs/BMIs that are described in the article.

Citation:  Carmena J and Millán J. (2013). Brain–Machine Interfaces: Your Brain in Action. Front. Young Minds. 1:7. doi: 10.3389/frym.2013.00007

 

Reflect on What You Learned

After reading the article, complete a short quiz. Re-arrange the images below to show the process of how a BCI or BMI works.

 

Part 2: Biosignals

As the video and article pointed out, are an important component of BCIs. Biosignals are signals generated by the human body that can be measured. As you learned yesterday, neurons produce both electrical and chemical signals in order to communicate. Bioelectrical signals are electrical signals produced by the nervous system (e.g., EMG, EEG, ECoG) or organ systems (e.g., ECG/EKG, GSR).  Electrical signals produced by in the nervous system are of major interest to neural engineers.  Many communicate with the human body through the use of EEG or ECoG that record neural signals from the brain or spinal cord. Some neuroprosthetic devices rely on EMG electrodes that record skeletal muscle activity, or more precise electrodes (intraneural and extraneural) that can record from individual neurons in the peripheral nervous system. Some devices, including deep brain simulators (DBS) use electrodes surgically inserted into the brain. Here is a quick overview of ways of measuring and recording these biosignals:

 

  • : Monitors brain signals with electrodes that are placed on the surface of the brain. Invasive, requires surgery.
  • : Monitors brain activity with electrodes that are placed on top of the scalp. Non-invasive.
  • : Monitors skeletal muscle activity with electrodes that are placed on the skin. Non-invasive.
  • : Directly records activity from neurons with electrodes that are surgically inserted into brain tissue. Invasive, requires surgery.

 

are able to communicate with the human body by using electrodes that record bioelectrical signals generated by the brain, spinal cord, skeletal muscles, and peripheral nerves.

 

Look at This!

Check out this amazing graphic on “Brain Interfacing” to learn about the pros’ and con’s of each of these ways of recording and measuring neural signals. (Credit for this graphic goes to Scott Leighton.) Then hit the “back” arrow on your web browser to return to this chapter and continue reading.

 

Neural engineers are able to obtain these biosignals by using to measure and record the signals. Electrodes are conductors in which electricity enters or leaves an object. In neuroscience, electrodes are used to detect biosignals produced by the body. Electrodes are used in , , , and other methods to record the electrical activity generated by neurons. These electrode can be placed on the surface of the skin, onto the surface of the brain under the skull, or inserted directly into the brain or spinal cord. Some electrodes are engineered to also be able to provide electrical stimulation, light (optogenetic) stimulation, and/or deliver small amounts of pharmaceutical drugs. These kinds of electrodes are made from metal, glass, glassy carbon, and other materials that do not react when surgically implanted into the body. Some electrodes are made to be flexible so that they can move with the tissue.

 

Optional: Read This to Learn More!

If you would like to learn more about biosignals, the article “Neuroprosthetics” from The Scientist provides a deeper explanation of how neuroprosthetics use electrodes to measure and record biosignals.

Open-Loop vs. Closed-Loop BCIs

In an open-loop BCI, the person using the device does not receive any feedback about the operation of the system.  However, in a closed-loop BCI, the users see, hear or feel what the device is doing and can use this information to change what they are doing.  It may even be possible to develop a BCI that sends sensory feedback via electrical stimulation of the brain.

Part 3: CNT Research Spotlight

Researchers at the Center for Neurotechnology are involved in many aspects of developing better brain-computer interfaces, including cochlear implants, deep brain stimulation, brain-to-brain communication, and prosthetic limbs. In today’s CNT Research Spotlight, we focus on a team of researchers that are using closed-loop BCI technology to develop prosthetic limbs that allow the users to touch and feel. First, listen to a radio story and then read a short article about these amazing neuroprosthetics.

 

 

Listen to This!

Listen to a short three-minute radio story from KNKX about Dr. David Caldwell, a bioengineer at the University of Washington. “UW Team Works to Develop Prosthetic Limbs that Help Users Touch and Feel.”

(A transcript is not available, but there is a brief article covering similar information on the website.)

Read This!

After listening to the radio story, read the article, “An Unexpected Difference in Reaction Times to Artificial and Natural Touch” to learn more about Dr. Caldwell’s research project.

 

 

Part 4: Types of Brain-computer interfaces

There are three common types of brain-computer interfaces. These include:

  • Neuroprosthetics
  • Retinal Implants
  • Cochlear Implants

 

Optional: Learn More! 

If you would like to learn more about BCIs, we’ve curated a list of learning resources for you to explore, organized by type of BCI. Enjoy!

Option 1: Learn More About Neuroprosthetics (Bionic/Robotic Limbs)

Learn more about research breakthroughs in the field of limbs by exploring these resources:

Option 2: Learn About Cochlear Implants (for deafness and hearing impairments)

 Learn about by exploring these resources. You will need speakers or headphones for many of these online activities.

  • The article, “Bionic Senses” from Harvard University, provides background information about how neuroprosthetics can help restore sight and hearing through the use of cochlear and retinal implants.
  • This factsheet from the NIH provides a good introduction to cochlear implants.
  • What is it like to experience hearing loss? Try out the Hearing Loss Simulator from Hearing Like Me to help you understand mild and moderate hearing loss.  Listen to sixteen different recordings at normal hearing compared to mild and moderate hearing loss.
  • Hear the World Foundation also has an online demonstration of What Hearing Loss Sounds Like. You will need speakers or headphones for this to work.
  • What is it like to have a cochlear implant? The Cochlear Implant Audio Demos (developed by Philipos C. Loizou) allows you to explore what happens when the number of channels is changed or the depth of the electrode is adjusted on the clarity of human speech processed through a cochlear implant.
  • It is important to note that cochlear implants can be controversial, because some people believe that cochlear implants are an affront to the Deaf community and their culture.

Option 3: Learn about Retinal Implants (for blindness and vision loss)

Learn about  by exploring these resources:

  • The Artificial Retina Project has a graphic that explains how a retinal implant works to restore some vision in people with certain kinds of blindness.
  • The Scientist provides a series of short articles that offer a general overview of retinal implant devices.
  • The article, “Bionic Senses” from Harvard University, provides background information about how neuroprosthetics can help restore sight and hearing through the use of cochlear and retinal implants.

 

Tomorrow we will focus on treatments for neurological disorders, diseases, and injuries that make use of electrical stimulation of the brain and spinal cord. Our guest speaker will be Dr. Chet Moritz, who studies spinal stimulation therapy with patients who have had a spinal cord injury.

 

 

Optional Resources

 

Citations:

  • BCI and wheelchair image: Carmena J and Millán J. (2013). Brain–Machine Interfaces: Your Brain in Action. Front. Young Minds. 1:7. doi: 10.3389/frym.2013.00007.
  • Icons for quiz: Flaticon.com.
  • Research highlight photos: Center for Neurotechnology.

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Virtual REACH Program 2020 by Center for Neurotechnology, University of Washington is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

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