Word-level language modeling for P300 spellers based on discriminative graphical models.

TitleWord-level language modeling for P300 spellers based on discriminative graphical models.
Publication TypeJournal Article
Year of Publication2015
AuthorsSaa, JFDelgado, de Pesters, A, McFarland, DJ, Çetin, M
JournalJ Neural Eng
Volume12
Issue2
Pagination026007
Date Published04/2015
ISSN1741-2552
KeywordsBrain Computer Interfaces, inference algorithms, language models, P300 speller, probabilistic graphical models
Abstract

OBJECTIVE: In this work we propose a probabilistic graphical model framework that uses language priors at the level of words as a mechanism to increase the performance of P300-based spellers.

APPROACH: This paper is concerned with brain-computer interfaces based on P300 spellers. Motivated by P300 spelling scenarios involving communication based on a limited vocabulary, we propose a probabilistic graphical model framework and an associated classification algorithm that uses learned statistical models of language at the level of words. Exploiting such high-level contextual information helps reduce the error rate of the speller.

MAIN RESULTS: Our experimental results demonstrate that the proposed approach offers several advantages over existing methods. Most importantly, it increases the classification accuracy while reducing the number of times the letters need to be flashed, increasing the communication rate of the system.

SIGNIFICANCE: The proposed approach models all the variables in the P300 speller in a unified framework and has the capability to correct errors in previous letters in a word, given the data for the current one. The structure of the model we propose allows the use of efficient inference algorithms, which in turn makes it possible to use this approach in real-time applications.

URLhttp://www.ncbi.nlm.nih.gov/pubmed/25686293
DOI10.1088/1741-2560/12/2/026007
Alternate JournalJ Neural Eng
PubMed ID25686293
Grant ListEB00085605 / EB / NIBIB NIH HHS / United States
P41 EB018783 / EB / NIBIB NIH HHS / United States
R01 EB000856 / EB / NIBIB NIH HHS / United States

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