We may have often dreamt of reading other people’s minds to gain a competitive advantage in preventing tragedies and crimes, developing closer relationships and treating diseases. With that in mind, neuroscientists from the University of Glasgow have now decoded brainwaves to read minds. They were apparently able to recognize the type of information contained within certain brainwaves related to vision.
Brainwaves are known as the patterns of electrical activity created in the brain when it is engaged in different activities. Generally brainwaves may be measured through electroencephalography (EEG). Understanding what information is encoded within them, and how that encoding takes place, is a mystery. For decoding some of these brainwaves, experts enrolled 6 volunteers in a series of experiments. The participants were made to view images of people’s faces, displaying different emotions like happiness, fear and surprise.
“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,” added Professor Philippe Schyns, Director of the Institute of Neurosciences and Psychology and the Centre for Cognitive Neuroimaging, who led the pioneering study.
During different experimental trials, parts of the images were randomly covered so say only the eyes or mouth was visible. Subjects were then asked to identify the emotion being displayed. While performing this exercise the participants’ brainwaves were measured via EEG. As a result, authors were capable of laying hands on parts of the brain that were active when looking at different parts of the face.
Prof Schyns remarked, “By using multiple frequencies to encode two different parts of the face – a process called multiplexing – the brain can code more signals at the same time. It is a bit like radiowaves coding different radio stations at different frequency bands. Likewise, the brain tunes in different waves to code different visual features. This work has huge potential in the development of brain-computer interfaces.”
Brainwaves seem to vary widely in frequency, amplitude and phase. In the course of the study, it was observed that ‘beta’ waves which have a cycle of 12Hz carried information about the eyes, while ‘theta’ waves at 4Hz encoded information about the mouth. Information may be primarily encoded depending on the phase or strength. The study findings are believed to provide a deeper insight into various brain processes.
The study is published in the latest edition of PLoS Biology.