A new technology, sono-optogenetics, is being experimented to support brain-computer interfaces -BCI.
BCI aims at capturing the brain activity, convert it into bits and provide these bits to a computer for analysing what is going on, eventually what you are thinking. Let’s clarify that we are still very – very – far from that, so don’t get scared – for now. What researchers have been able to achieve is to detect, by looking at the brain electrical activity in some specific areas, that you would like to “tell” your hand to move and pick up something (the computer -after some training- detects that you are intending to move your hand, understanding “why” you want to move your hand may derive from other -contextual- information, not from thoughts in your brain, they cannot be detected – so far).
We have seen demonstration of these capabilities with paraplegic persons that where able to use these BCI to control a robot and had it serve a drink or have an assisted walk through an exoskeleton (for updated research results you can read this paper).
The better the electrical activity of the brain can be captured (with higher resolution and less noise) the more chances to process the data and derive meaningful information. So far the closer you can place the sensors to the brain’s areas you need to monitor the better. That means that the best signals are obtained by sensors embedded (via surgery) in the brain, second best by overlaying them on the brain meninges (surgery again) and last by placing them on the skull.
Now researchers at Caltech have found a way to use ultrasounds to detect brain activity. The ultrasounds can be focussed on specific areas of the brain to detect minimal changes in blood circulation (with a 10µm resolution). We know that when a certain area of the brain is engaged in an activity it demands more blood and this demand can be visualised by this ultrasonic technique.
In particular the researchers have demonstrated that they are able to detect movement intention (these are usually the ones easier to detect since one can focus on the motor area of the brain) of a primate using ultrasound.
You can get all details in the article published on Neuron.
This technology is very interesting since it is way less invasive and yet it can deliver quality data for analyses. It is another (tony) step towards more effective BCI.
The name “sono-optogenetics” is created by coupling “sono” (sound) to “optogenetics“, a technology that allows researchers to fiddle with the brain, sending messages (using light and optical fibre plus making neurones sensitive to light using virus carried molecules – seems scaring and it is…) to specific neuronal circuits to influence their behaviour. Notice that optogenetics is an invasive procedure (it involves surgery).
There are also studies that show how the use of ultrasounds can affect the behaviour of neurones and this is what the Caltech researchers are studying, to obtain a bi-directional BCI. Again, we are very far from the possibility of both reading “the mind” and controlling it (much easier to do that with television, internet and ads…).