BYB’s Odd Consciousness Detector

Welcome! This is Kylie Smith, a Michigan State University undergraduate writing to you from a basement in Ann Arbor. I am studying behavioral neuroscience and cognition at MSU and have been fortunate enough to have landed an internship with the one and only Backyard Brains for the summer. I am working on The Consciousness Detector – an effort to bring neuroscience equipment to the DIY realm in a way that allows us to learn about EEGs, attention, and consciousness. It is my mission to create an oddball task that elicits the P300 signal in such a way that can be detected on BYB’s EEG machine. Let me break it down:

An oddball task is an attentional exercise in which a participant sees or listens to a series of repeating stimuli. These stimuli are infrequently interrupted by a novel stimulus called the oddball stimulus. The participant is asked to count or press a button for each oddball stimulus that is seen. Named so for its positive change in voltage occurring around 300 ms after the appearance of the oddball, the P300 can be seen when the participant is attending to the stimuli and the oddball they had been waiting for arrives.  This signal can be detected by an electroencephalogram, or EEG. EEGs use a series of small, flat discs, called electrodes, in contact with the scalp to detect changes in voltage through the skull. The EEG detects the changes in the electrical activity of neurons and transmits the detected signals to a polygraph to be analyzed. Outside of my project, EEGs can be used to help diagnose certain neurological disorders and help pinpoint locations of activity during seizures.

So why is this project worthwhile? Consistent with BYB’s mission statement, we want to bring neuroscience to everyone. Your average neuroscientist spends years learning the mechanisms behind brain funtion in order to use this knowledge practically. Then the equipment must be conquered – it is often complicated and lots of time is dedicated to mastery. By hacking their own EEG and producing it from basic electronic components, BYB is able to bring this machinery to you – and that is an incredible thing. Learning the principles behind EEG recording and how to use such a machine is something that few have the opportunity to do – and now you can do it in your living room! The idea behind The Consciousness Detector is used in the medical field. Patients with severe brain damage can be given an auditory oddball task to objectively predict recovery of consciousness through the P300 that is or is not present (If interested, please see: Cavinato et al. (2010) Event-related brain potential modulation in patients with severe brain damage). We are bringing medical techniques used to predict prognosis to you. Yay!

The current BYB EEG headband is being employed to record from the parietal lobe, as this is where the P300 is detected the strongest. A better apparatus for holding electrodes in place will most likely be introduced down the line. I have high hopes to pop some rivets into a home-made brain hat and begin an EEG cap trend. For now, this is what I’m working with:

Backyard Brain’s EEG system uses two active electrodes, the electrodes recording activity, and a ground to eliminate noise common to the head. I have attempted to begin as simply as possible to determine what kind of oddball task is required to elicit the P300. The arduino shield produced by BYB has  a series of LEDs, shown in the picture to the right, that I have used in my first version of the task. We coded the LEDs to flash in a random sequence with the oddball stimulus flashing 10% of the time, as a smaller probability of seeing the oddball predicts a larger amplitude and more easily detectable P300. The standard and oddball LEDs were assigned to corresponding digital outputs on the arduino and were wired into the analog input so that each flash could be detected on the Spike Recorder app. In the picture below, the green signals represent the standard LED flash and the red represents the oddball LED. Using this method, we can see what occurs 300 ms after the oddball LED is flashed. To ensure that attention is required to detect the oddball, we began by using one green LED as the standard stimulus and the other green LED as the oddball flashing 10% of the time. After getting no response in that department we tried other colored LEDs as the oddball, thinking that two green LEDs may be too similar since the oddball stimulus is intended to be more novel than the standard. No P300 was observed there, either.

We have written another oddball task using LEDs in which the LEDs randomly flash two at a time. The task of EEG-wearer is to count how often symmetric stimulation occurs across the LED midline. This task gives a more novel oddball and hopefully an easily detectable P300! More oddball options are in the works, including small images for a visual oddball and auditory tasks as well! Stay tuned 🙂

Neural Interfaces Desde Santiago Hasta Oaxaca to Ann Arbor

In March 2014 we went to Mexico’s first Maker Faire, invited by Amor Muñoz, a Mexican Textile and Electronic artist, who we met at Chile’s Santiago MakerFaire in November 2013. The Mexico MakerFaire took place in Oaxaca, a place known for traditional crafts, pero ahora se esta transformando en un lugar de “Nuevos-Makers” de diseño, electronica, etc.

During this MakerFaire, we ran a two day workshop where we met Jose Enrique, un alumno de ingeniera electronica. He knew his electronics, y nos ayudó mucho durante el taller. Jose asked if he could have some extra equipment for his studies – specifically, an extra Arduino for more experiments with the EMG SpikerShield.

We said, “Sure, but promise us that you will send us a video of something you did with this gear, with a deadline of three weeks.” Y el lo hizo, tres semanas después nos envió un video de liquid cystal display (LCD) contralado con la actividad de sus músculos. So….Let’s do more! We gave him a job offer to design “three interfaces” with the EMG SpikerShield, and importantly, write them up in BYB style so we could add them to our website. Durante Mayo y Julio, trabajabamos en equipo, and now it’s ready – Versión en English – Version in Español). You can learn how to control a stepper motor, an LCD screen, and a Gripper arm with your muscle activity!

Cuando todo estaba listo,  we asked Jose, “Gracias por tu buen trabajo, Can you send us your bank details so we can wire you the compensation for your good work?” Jose counter-offered, saying, “Can you send me an oscilloscope instead?”
Ummm….like… o sea….onda…  Yeah! we can do that. An engineer that wants to be paid in equipment that allows him to invent more? We approve. We bought the oscilloscope he wanted from Amazon and sent it on down to Oaxaca. It is now part of Jose’s lab. Gracias por tu trabajo Jose, e ¡inventa más! Con nuestros cerebros quemando con el fuego de creatividad y nuestras manos productivas podemos dar a luz cosas maravillosas a este mundo.  See Jose’s home lab below.  Eso es donde las ideas se transforman en realidad.

We should have expected no less. Our main method of communication has been through that popular invention of Mark Zuckerburg, and this is Jose’s profile photo. ¡Saludos! Stay tuned… we are now beginning to work on EEG’s together. Also, Happy Birthday Tesla!