Our brain is very much like an electric circuit, and far more so that most of us realize. Suffice to say that our brain almost literally uses electrical circuits that are perfectly analogous to the electrical circuits of a computer. These are our neurons, and it is by communicating via the ion channels at the end of our synapses that we are able to send signals around our brain. If you take any human experience like sight or vision, then ultimately it comes down to electrical signals.
While this might be a little jarring and give you something of a headache to consider, it also has some positive implications and it means for instance that our own technology is not far from being compatible with the human brain, and that we aren’t far from being able to make changes to that circuit which change the way the brain works and which can have many different applications. ‘Transcranial stimulation’ is a term that refers to a whole category of different techniques that take advantage of the brain’s nature and use this to potentially highly beneficial effect. Here we will look at what those benefits are, and precisely how transcranial stimulation would work.
Stimulating the Brain in Studies
We’ve already established that the brain runs on electricity. Networks of neurons represent brain ‘areas’ and science has demonstrated that different areas in the brain are used for different purposes. Thus if you can ‘light up’ one of these neural networks by running an electrical charge through it, or alternatively ‘shut down’ an area by cutting off that charge, you can alter which parts of the brain are working and how much.
This is something that scientists have known for a long time, and in open brain surgery some studies have been carried out using electrical stimulation to stimulate specific brain areas and monitor the results. In some cases during these studies the patients have been awake and have been able to report what it feels like from their point of view. In one case scientists stimulated the memory areas of the brain (the hypothalamus) and found that the individual suddenly experienced their own memories in vivid color – some of which they had previously forgotten. Using magnetic stimulation meanwhile the opposite effect could be achieved and precise areas of the brain could be ‘shut down’ resulting in a range of localized findings – such as patients losing the ability to name vegetables, or to name objects in their right field of vision.
In one very impressive study, magnetic stimulation was used in order to suppress the language centers of the brain and this resulted in the participants experiencing increased mathematical and logic skills while losing their language abilities – much like the symptoms of autistic savantism.
Deep Brain Stimulation
These studies would later give way to what is known as ‘deep brain stimulation’ as a treatment. Here a surgeon would perform open brain surgery and then use this to implant electrodes deep inside the patients’ brains at specific points. The electrode could then be controlled externally in order to stimulate or suppress activity in that area and this has been used successful to treat a range of conditions from depression, to obesity (by suppressing appetite) to epilepsy. Of course this is an incredibly invasive procedure and most people would be opposed to the idea of having an electrode permanently implanted into their head which greatly limits the scope of this technology.
Transcranial Direct Current Stimulation
Transcranial direct current stimulation then is a way of stimulating the brain through the scalp (transcranial) so that the device responsible never needs to be actually implanted. This makes it far more practical as a form of treatment for a range of conditions and someone with chronic obesity is of course going to be more likely to respond to the idea of using an unusual hat rather than having something implanted into their actual brain. Direct transcranial current stimulation involves using lots of tiny shocks to the brain that go through the scalp via pads that are similar to the pads you get with tens machines and electrical muscle stimulators. Of course direct transcranial current stimulation (or DTCS) is not yet as accurate as using deep brain stimulation and has not yet completely replaced it for medical purposes. With TDCS it is only possible to select areas that are four centimeters in diameter in order to affect and this of course means it can’t be quite used to address very specific symptoms without having side effects. Likewise in order for TDCS it is necessary for the pads to be placed directly against the scalp with some water or gel between them and the skin – which means that some areas of the head need to be shaved.
However the technology is nevertheless improving in accuracy all the time and it has already shown to have many applications. In one study for instance TDCS was used to improve the learning of hand movements by a researcher called Cohen.
Other Technologies
Fortunately though, TDCS is not the only promising area of transcranial stimulation. For instance some research is looking at using ultrasound. This wouldn’t light up or suppress areas of brain activity directly, but rather would be used in order to knock open the ion channels and thus cause the cells to fire. This research is in its very early stages, but it is possible theoretically to affect areas as precise as 1-3 cubic millimeters and there is no need for the hair to be shaved or for water or gel to be used.
Meanwhile transcranial magnetic stimulation has also been demonstrated successfully to be able to treat a range of conditions and is already used in some hospitals as a form of treatment for depression. In fact there is already a commercial product available that allows individuals to use this same device at home. The device is called the ‘Neuralieve’ which can be purchased online and then used to combat depression and anxiety as well as headaches according to the manufacturer.
Conclusion
Currently we are still in the early stages of development but these technologies do suggest that we are getting closer to being able to alter the way the brain works temporarily without the need for any invasive surgery. This has countless applications and might help patients to recover from conditions such as anxiety, depression, obesity, epilepsy and more, but could also help us to improve our learning, our brain function and our mood.