As of the beginning of this September, I am now working at the Institute of Neurophysiology at Hamburg’s University Medical Center. I am part of the EEG lab team where I am assisting in carrying out EEG brain measurements on study patients. Once the measurements are taken via a complex collection of electrodes placed on a hood-like cap, it is my job to analyse the raw data and eventually draw conclusions.
Before I go further I want to explain a few basics of measuring brain waves:
Basically, the most interesting property of neurons is their neural oscillation. This oscillation can be measured as a signal on an EEG device.EEG (=ElectroEnzephaloGraphy) is a method by which one can measure electrical activity along a human’s scalp. The EEG device measures the voltage that results from the current flow of the neurons (=nerve cells) inside our brain.
Oscillations exist in varying forms with distinguishing frequencies. Neuroscientists usually differentiate between 4 different frequencies. These frequencies are usually good detectable on the EEG depending on which state the tested person is in.
Many studies have been done monitoring people’s EEG but what happens when the brain is stimulated in a way such that the typical brain waves are altered?
One such method to excite or stimulate the neuronal activity inside the brain is by using a technology that is called Transcranial Alternating Current Stimulation (=tACS). Now, I have written about the more common use of tDCS which uses a direct current as opposed to the alternating current used in tACS to run a very small current across the scalp.
EEG + tACS = Better Learning?
Using tACS and measuring EEG at the same time has not been studied extensively. We let the subject perform simple visual tests where the person is presented identically sized rectangles on a screen while being hooked up to the EEG and tACS devices. Each time the rectangle changes its size – the person is instructed to punch a button. This „punch“ can be well detected on the EEG monitor. With the tACS doing its current stimulation at the same time, the hypothesis is that tACS may improve this person’s performance at the test. This theory is still out there to test but if it proves correct, it may well be transferred to different areas of motor learning.
The project is still in its infant stage but the potential is huge for making advances in this field. Sometimes, I feel like a mad scientist from the 19th century running an electric current across my head and just seeing what happens next. Maybe in a few years time, we will know enough about the brain and stimulation so that we can easily improve someone’s cognition and learning speed just by stimulating them with the right frequency.