Researchers have shown that it is possible to reconstruct basic units, words and complete sentences from brain waves, and then generate the resulting text. They say that speech, which is produced in the cerebral cortex, can be directly recorded with electrodes located on the cortex surface.

Brain activity recorded by electrocorticography electrodes (blue circles). Spoken words are then decoded from neural activity patterns in the blue/yellow areas. (Image credit: CSL/KIT)Brain activity recorded by electrocorticography electrodes (blue circles). Spoken words are then decoded from neural activity patterns in the blue/yellow areas. (Image credit: CSL/KIT)Researchers from Karlsruhe Institute of Technology (KIT) in Germany and the U.S.-based Wadsworth Center presented their “brain-to-text” system in Frontiers in Neuroscience.

"It has long been speculated whether humans may communicate with machines via brain activity alone," says Tanja Schultz, who conducted the study with her team at the Cognitive Systems Lab of KIT. She says her team’s recent results indicate that both single units in terms of speech sounds as well as continuously spoken sentences can be recognized from brain activity.

The team did this by recording brain activity from seven epileptic patients who each had an electrode array placed on the surface of his or her cerebral cortex. Patients then read sample texts aloud and researchers analyzed the data to develop brain-to-text.

"In addition to the decoding of speech from brain activity, our models allow for a detailed analysis of the brain areas involved in speech processes and their interaction," say Christian Herff and Dominic Heger, who developed the system as part of their doctoral studies.

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