Surfing the alpha waves
I always thought that EEG was hard. Not so much getting the information about brain activity, but more about what you have to use to get that information — those weird shower caps with a thousand sensors and wires all over the place. How things have changed.
I’ve discovered that there a now a wide range of commercially available products that enable tracking of brain activity. Amazing.
From a commercial product perspective, these products are aimed at helping people relax and develop focus. However, they do record and provide an amazing array of information.
Image source: Flickr Creative Commons Group, Valentia_A, “Hypnotic Waves”, 27 August 2007. Retrieved from: Click here.
Brainwaves
Sources: wikiepedia and choosemuse.com — just to provide some high level background
Brainwaves are typically broken into 5 bands:
Delta
Present during sleep. Usually associated with deep stage 3 of NREM sleep. Help to characterise depth of sleep. Originate in either the thalamus or in the cortex.
Theta
Related to sleep, very deep relaxation and visualisation. Originates from the hippocampus and because this is so deep in the brain it is difficult to clearly identify.
Alpha
Related to being relaxed and calm but with eyes closed. They are reduced with open eyes, drowsiness and sleep. Predominantly originate from the occipital lobe
Beta
Occur when actively thinking or problem solving, when a person is busy, or anxious thinking and active concentration. If they occur over the motor cortex they are associated with isotonic muscle contractions. They are suppressed prior to and during movement changes.
Gamma
Occur when engaged in higher mental activity and consolidation of information. The claim is that the thalamus sweeps the brain from front to back numerous times per second drawing different “neuronal circuits” into synch. This helps to bring up memories and associations. Often they arise from visual cues. They are also implicated in REM sleep, which involves visualisations.
Here’s a quick review of some of these bands based on features that I think are important for this project. Importantly, all of these products have an API.
Muse
I have posted a link to muse in a previous post.
Muse is interesting because it is a nice neat headband. It tracks brain activity across the different wave frequencies — Delta, Theta, Alpha, Beta, and Gamma.
Using an application called “calm”, muse uses the detected brainwaves to determine whether you are “calm”, “active” or “neutral”.
Through visual and audio feedback, calm aims to help the user to “train their brain” to remain calm and settled.
emotiv
emotiv target research contexts.
They have three headsets each with different functionality. Their main headset, EPOC+ provides 14 EEG channel locations.
Most significantly, they provide detection libraries for:
- facial expression — blink, wink, raise brow (surprise), clench teeth (grimace) and smile;
- performance and emotional metrics — instantaneous, excitement, long term excitement, stress, engagement, relaxation, interest, and focus; and,
- mental commands — neutral plus up to 4 pretrained items from a list of labels including: push, pull, levitate, rotate and more difficult commands such as disappear.
The insight device has only 5 channel locations. However, it is the nicer sleeker design (not quite as obstrusive as the EPOC models). It also has 3x gyro, 3x accelerometer, 3x magnetometer.
A number of applications are available for the headsets including brain activity maps, cognitive trainer, and control panels.
mindwave
This is the mindwave by neurosky. A little less obtrusive than the EPOC but more than the insight.
The information on the NeuroSky website is not as complete as the other products. Really, all that is stated is that the device tracks EEG and ECG related data.
The visualisation is interesting though showing brain activity across the different brainwave groups as well as providing an indication of Attention and Meditation.
More information about what is classed as “attention” and “meditation” would be useful. However one clear benefit is that is does track ECG data, which is very useful.
Use in research
One of my main concerns is whether these devices provide information or data that is reliable enough to be used in research.
Clearly the EEG signals are not meant to be of sufficient quality to enable medical or neurological diagnosis. However, these types of devices have been used for brain to computer communication based on brain activity (Liao, Lin, McDowell, Wickenden, Gramann, Jung, Ko, and Chang, 2012 — click here to access this reference).
Crowley, Sliney, Pitt and Murphy (2010 — click here to access this reference) evaluated the NeuroSky Mindset. They found that the device was a suitable device for measuring “attention” and “meditation”in a minimally invasive way.
Hondrou and Caridakis (2012 — click here to access this reference) conducted a review of research work that used NeuroSky and emotiv.
It seems that these commercially available products are able to provide data that is useful for research purposes within the areas of affective computing and brain to computer interaction.
