DIY mobile EEG – a serialized blog approach
For a long time, I have wanted to expand my lab facilities to be able to record not only behavioural data at millisecond resolution, but also to expand with neuroimaging such as EEG. Although I am already doing neuroimaging using functional and structural MRI at the DRCMR, I have had an interest in trying other modalities such as the EEG. The EEG, despite it’s well-known lack of spatial resolution and mainly cortical focus, other factors are notable, including
- a less artificial environment compared to fMRI and PET imaging
- no noise, less intrusions on the subject
- fewer constraints on experiment design, such as the need for several iterations of typified situations as used in fMRI
- high temporal resolution
- better integration with other modalities such as eye-tracking
- recent advances in mobility that allows for studies with better ecological validity
Now, I’m expanding my lab facilities to include both high resolution eye-tracking and stationary/mobile EEG, and it’s on the cheap! In this blog post series, I will present the work we’re doing to employ these methods in the lab, as well as outside in the “real world”.
For starters, I have chosen to go with the Emotiv 14-channel system, purchasing the SDK version for $799. As a stand-alone product this seems to work very nicely for obtaining electrical signals, and has both metrics for signal value and accelerometers for head movements. We have now made two solutions for use of this equipment: one for stationary testing, which also includes eye-tracking, and one for mobile settings:
The stationary set-up
In close collaboration with iMotions, we have developed a nice interface for obtaining the EEG signals, through their Attention Tool®, and been part of developing this and other features for their Sensor Sync module. Through this module we’re not only able to integrate EEG but also any other suitable module that provides an SDK, so there will be more to come.
In out stationary set-up, we’re running a Tobii eye tracker and running the Attention Tool, which now has a nice integration of the EEG signal, as can be seen in the picture below:
Screen shot of Attention Tool® Setup with the Emotiv EEG integration (bottom middle).
As can be seen from the colour of the electrodes, the signal for the current session was not optimal
The mobile setup
For the mobile setup, we have acquired a Nokia N900, which our collaborators have integrated with the Emotiv system (see my prior blog post on this):
Mobile Emotiv setup: the Nokia N900, the Emotiv system, saline water and the electrode containment box
And here is how it looks when one of my graduate students, Dalia Bagdziunaite, wears the system and watches her own brain activation – yes mobile biofeedback it is!
Alpha band activation is projected on to a 3D brain model, here showing increased bilateral prefrontal activation.
What is still needed is a better mode of determining what subjects are looking at. One intermediate solution for us has been to obtain a pair of HD video glasses from SpyTech, which we are currently waiting for, and which will be integrated and synched with the Nokia setup. All solutions still at low cost. Right now, we will use this to grossly know what a person is looking at, but of course, we want to expand this with more sophisticated tools, such as Tobii’s new glasses.
So, in coming blog posts, I will describe some of the work, challenges and solutions we have for working with this system, and in which contexts we will be using it, including in-store purchase, gambling, art exhibits, psychiatric disorders, and neurofeedback.