Listening to heard and thoughts using brain waves?
Heard speech can be recognized by brain waves, US scientists report on the portal "PLoS Biology". Possibly, thoughts could also be overheard with a comparable method, according to the daring thesis of the researchers.
The US research team led by Brian Pasley from the Helen Wills Neuroscience Institute at the University of California at Berkeley has found a way to recognize heard words using brain waves. The scientists were able to deduce what they were hearing from the nerve signals of their subjects. Brian Pasley and colleagues come to the conclusion that the human brain uses fixed mechanisms that "decode the highly variable acoustic inputs into meaningful elements of language such as phonemes and words."
Electrodes in the brain capture the neuronal signals of speech processing In order to obtain the data for speech processing in the brain, the US researchers used a very rare neurosurgical method, which is used in the treatment of epilepsy. Brian Pasley and colleagues were able to place 15 epilepsy patients in the brain as part of a neurosurgical intervention and thus measure the "neuronal activity" directly on the "cortical surface" - the brain region important for speech recognition. This offered "a unique opportunity" for studying speech recognition in the human brain, according to the US researchers. In a first test step, the test subjects were read various English words, with the US scientists identifying the electrical signals occurring in the brain. Based on these neuronal signals, the scientists developed a computer model that can convert the recorded nerve signals back into sounds. These computer sounds were played to other research colleagues and were recognized relatively often as the originally spoken words. Even if not every word could be identified exactly, the speech recognition was clearly above a randomly expected probability, the US scientists explained.
Mind reading based on brain waves? Since "there is" some evidence "that" perception and imagination are the same in the brain, "study leader Brian Pasley already speculated about a next procedural step in which the scientists could literally read minds. "If you understood the relationship between the brain recordings and the sound well enough, it would be possible," according to the US scientist, "to make it audible what a person is thinking." However, it has to be clarified in advance, whether even the merely imaginary words produce comparable brain signals as heard words. If the speculations of the US scientists are confirmed, the electrodes in the brain could be used in a variety of ways. It might even be possible to enable people who are unable to speak to communicate again using words. However, numerous forms of misuse of such a method are also conceivable. Under certain circumstances, the electrodes in the brain could replace previous torture methods and be used to get other people's thoughts. Regardless of which applications are still being developed based on the current research results, the US neuroscientist led by Brian Pasley has in any case taken an important step towards understanding speech processing in the brain. (fp)
Brain growth through maternal attention
Mechanism of brain development deciphered
Being overweight shrinks the brain
Image: Gerd Altmann / pixelio.de