Decoding spoken words using local field potentials recorded from the cortical surface

Spencer Kellis, Kai Miller, Kyle Thomson, Richard Brown, Paul House, Bradley Greger
2010 Journal of Neural Engineering  
Pathological conditions such as amyotrophic lateral sclerosis or damage to the brainstem can leave patients severely paralyzed but fully aware, in a condition known as "locked-in syndrome." Communication in this state is often reduced to selecting individual letters or words by arduous residual movements. More intuitive and rapid communication may be restored by directly interfacing with language areas of the cerebral cortex. We used a grid of closely spaced, nonpenetrating microelectrodes to
more » ... cord local field potentials (LFPs) from the surface of face motor cortex and Wernicke's area. From these LFPs we were successful in classifying a small set of words on a trial-by-trial basis at levels well above chance. We found that the pattern of electrodes with the highest accuracy changed for each word, which supports the idea that closely spaced micro-electrodes are capable of capturing neural signals from independent neural processing assemblies. These results further support using cortical surface potentials (electrocorticography) in brain-computer interfaces. These results also show that LFPs recorded from the cortical surface (micro-electrocorticography) of language areas can be used to classify speech-related cortical rhythms and potentially restore communication to locked-in patients.
doi:10.1088/1741-2560/7/5/056007 pmid:20811093 pmcid:PMC2970568 fatcat:qvv4smgeqbgwhj4vuq26j4rulu