Imagine being so paralysed you cannot speak. This, sadly, can result from a condition such as stroke.
Achieving even very limited communication is vastly better than none. Scientists from the University of Utah in America have made a break through in establishing a link between specific words and signals from the brain. This may allow paralysed patients with ‘locked in syndrome’ –( a condition in which a patient is aware and awake but cannot move or communicate verbally due to complete paralysis of nearly all voluntary muscles in the body except for the eyes.) to communicate. Researchers from the university implanted two grids of sixteen microelectrodes in a volunteer who already had part of his skull removed as part of a treatment for severe epilepsy. They then recorded the brain signals as the volunteer repeated ten words.
By analysing the changes in the strength of different frequencies within each signal, the researchers tried to establish which patterns in the signals corresponded to which word. When comparing signals such as when ‘yes’ or ‘no’ was mentioned, the researchers could identify the pattern correctly 76-90% of the time. But when all 10 signals of the brain were examined at once, the percentage dropped to 28 – 48%.
This appears to be a better chance than the 10% would have been. The scientist behind the scheme, Professor Bradley Greger and his team are making the grids bigger which will allow more data and increase the accuracy of identification. They will have more electrodes and will be able to provide more information about what word is actually being spoken. Better algorithms are also being developed which should improve performance. Programme 3 of the series presents the wonders of human mind and consciousness. Part of the wonder is that breakdown of the system is not more common!”
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