Decoding Brain waves to read it !
Researchers at the Institute of Neuroscience & Psychology have been able to identify the type of information contained within certain brainwaves related to vision. Brainwaves – the patterns of electrical activity created in the brain when it is engaged in different activities – can easily be measured using electroencephalography (EEG). However, knowing exactly what information is encoded within them, and how that encoding takes place, is a mystery. Professor Philippe Schyns, Director of the Institute of Neurosciences & Psychology and the Centre for Cognitive Neuroimaging, who led the pioneering study, said: “It’s a bit like unlocking a scrambled television channel. Before, we could detect the signal but couldn’t watch the content; now we can. “How the brain encodes the visual information that enables us to recognise faces and scenes has long been a mystery. While we are able to detect EEG activity in certain areas of the brain when particular tasks are performed, we’ve not known what information is being carried in those brainwaves. “What we have done is to find a way of decoding brainwaves to identify the messages within.”
In order to decode some of these brainwaves, the scientists at Glasgow recruited six volunteers and presented them with images of people’s faces, displaying different emotions such as happiness, fear and surprise. On different experimental trials, parts of the images were randomly covered so that for example, only the eyes or mouth were visible. The volunteers were then asked to identify the emotion being displayed. While engaged in this exercise the participants’ brainwaves were measured using EEG which allowed the researchers to identify which parts of the brain were active when looking at different parts of the face.
Brainwaves vary widely in frequency, amplitude and phase. In this study, the researchers found that ‘beta’ waves which have a cycle of 12Hz carried information about the eyes, while ‘theta’ waves at 4Hz encoded informationabout the mouth.