PMID-16838020[0] A high-performance brain-computer interface
- the speed and accuracy with which keys can be selected using BCIs is still far lower than for systems relying on eye movements.
- What is the eye-movement rate?
- implanted in PMD. 96 electrodes (utah array).
- used an instructed-delay task. figure 1
- monkey had to move to target when center target disappeared. peripheral target appeared several seconds prior.
- actually had the monkey reach to targets; if correct, monkey was immediately rewarded.
- real movement trials were interspersed to keep the monkey engaged.
- decoding model: assume that the spike counts come from a poisson or gaussian distribution. Apply ML decoding.
- poisson better than gaussian.
- up to 6.5 bits per second, or approximately 15 words per minute, with 96 electrodes.
- Peak of continuous control = 1.6 bits per second.
- ITRC = information transfer rate capacity. this metric is proportional to the single trial accuracy / trial length (sorta, see ref 23 - Blahut-Arimoto algorithm)
- most of their neurons seem to be responsive to actual movements (que supressa!)
- maximum bandwidth with a trial length of 250ms.
- lots of other good information-theoretic analysis.
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- PMID-12657892[1] Neural prosthetic control signals from plan activity. -- the preceding Neuroreport simulation study.
- performance to exceed 90% with as few as 40 neurons.
- maximum likelihood decoders controlling a FSM.
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