Recursive Bayesian Coding for BCIs.
IEEE Trans Neural Syst Rehabil Eng
; 25(6): 704-714, 2017 06.
Article
em En
| MEDLINE
| ID: mdl-27416602
ABSTRACT
Brain-Computer Interfaces (BCIs) seek to infer some task symbol, a task relevant instruction, from brain symbols, classifiable physiological states. For example, in a motor imagery robot control task a user would indicate their choice from a dictionary of task symbols (rotate arm left, grasp, etc.) by selecting from a smaller dictionary of brain symbols (imagined left or right hand movements). We examine how a BCI infers a task symbol using selections of brain symbols. We offer a recursive Bayesian decision framework which incorporates context prior distributions (e.g., language model priors in spelling applications), accounts for varying brain symbol accuracy and is robust to single brain symbol query errors. This framework is paired with Maximum Mutual Information (MMI) coding which maximizes a generalization of ITR. Both are applicable to any discrete task and brain phenomena (e.g., P300, SSVEP, MI). To demonstrate the efficacy of our approach we perform SSVEP "Shuffle" Speller experiments and compare our recursive coding scheme with traditional decision tree methods including Huffman coding. MMI coding leverages the asymmetry of the classifier's mistakes across a particular user's SSVEP responses; in doing so it offers a 33% increase in letter accuracy though it is 13% slower in our experiment.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Percepção Visual
/
Reconhecimento Automatizado de Padrão
/
Processamento de Texto
/
Córtex Cerebral
/
Eletroencefalografia
/
Potenciais Evocados Visuais
/
Interfaces Cérebro-Computador
Tipo de estudo:
Evaluation_studies
/
Prognostic_studies
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
IEEE Trans Neural Syst Rehabil Eng
Assunto da revista:
ENGENHARIA BIOMEDICA
/
REABILITACAO
Ano de publicação:
2017
Tipo de documento:
Article