Although I've only been a graduate student / research assistant for a couple years, this is my field. I'm not trying to be a dick with all my corrections and objections -- I'm trying to clear up misconceptions that tend to be a result of news articles that over-hype or misunderstand scientific findings on occasion. I am wrong sometimes and would like it to be pointed out when I am. If you're right, you're right regardless of my background and occupation. But news stories and TED talks aren't a good source to demonstrate it. Journal articles are a good source.
Ok.
Brain wave game controllers measure brain wave frequencies. The MRI game controller (I think you're talking about "Epoc") uses MRI and isn't a brain wave controller, so I assumed that wasn't what you were talking about. I was actually not aware of Epoc until I looked it up. The idea behind it is very cool.
The "not a brain wave controller" is somewhat confusing as it is the brain waves doing the controlling, but I take this a saying the brain waves aren't doing the controlling. Also note that even brain waves are a byproduct of neural firing, not the firing itself, not unlike the blood flow, or metabolism of sugar marked by blood oxygen changes, used by fMRI. Anyway, back to the Epoc case for instance.
The Emotiv EPOC actually provides developers with 3 implementation methods labeled Expressiv, Affectiv, and Cognitiv. These correspond to facial expressions, emotional states, and thought respectively. Now note, in all 3 the information is obtained from brain waves. The facial expression information does not come from observing facial expressions, it comes from mapping facial expression information from the brain waves. There remains a dictionary approach to interpretations that can be individualy defined. If you want to use brain waves in a more open ended way use the Cognitiv implementation.
My point was not specific implementations of brain wave monitoring, nor a claim that it represented mind reading in the sense a proclaimed psychic would imply, nor that it was direct reading of meaning associated with fine scale neural firing, or even that such techniques were direct unabstracted readings of neural activity, which they are not. What it does provide is commonalities in neural activity between brains, and provides enough location and location progression information learn the about the processes and locations involved in various experiences. We can abstract these out to build control devices based on facial expressions without bothering to monitor facial expressions, as in the EPOC case.
I'm less interested in these control devices, which do in fact involve dictionary outputs on very limited resolutions, than what can be learned about the brains operation principles in general. The abstraction between neural firing and the global monitoring techniques do not invalidate the fact that neural activity is being monitored with various levels of resolution and abstraction, and the only important feature between the various methods is the actual resolution to neural activity. I'll get to the single neuron case next.
Ideally you might want to, but we can't measure the activation of individual neurons, just general brain activity that is assumed based on things like oxygen distribution. Human neurons are (to my knowledge) too small to observe in action.
Single neuron activation:
http://www.nature.com/nature/journal/v451/n7174/full/nature06447.html said:
The sensory impact of individual cortical neurons therefore remains unknown. Here we show that stimulation of single neurons in somatosensory cortex affects behavioural responses in a detection task. We trained rats to respond to microstimulation of barrel cortex at low current intensities. We then initiated short trains of action potentials in single neurons by juxtacellular stimulation. Animals responded significantly more often in single-cell stimulation trials than in catch trials without stimulation.
If you want more info on "juxtacellular stimulation":
http://www-ulpmed.u-strasbg.fr/laec/juxtacellular_techn-UK.html
PDF link on page. It is far more precise than the traditional pointlike eclectic probe, which in spite of being pointlike tended to involve tiny bundles of neurons. The notion that the operational principles of our brain is structured such that single neurons play a significant role is more than a little suspect anyway. Yet the electric probe experiments can repeatedly produce very precise memories, complex actions, etc., without the subjects control. Even actions as complex as reliably lifting you hand to your mouth, among others.
Well, we don't know do we? Maybe you do, but I'd have to read the details of the study to know to what extent it was a success or failure.
The picture quality is about as poor as it gets. The implications are far more interesting than what was actually accomplished, and I have grave doubts about how much resolution is even possible in principle.
Back a few post, it was an explanation of why I doubt highly significant increases in resolution is possible, as I just mentioned above. It's certainly not authoritative, and would require an outline of a far more detailed modeling approach to do these assumptions any real justice.