An online single trial analysis of the P300 event related potential for the disabled

Brain computer interface (BCI) enables nonmuscular interaction with the environment. This interaction is particularly beneficial for those with impaired voluntary muscular activity. In this study, an online single trial analysis of a P300 dataset acquired using the six choice paradigm from four disabled subjects was conducted using a methodology involving the fuzzy k nearest neighbors classifier since an offline analysis and averaging many repeated trials in P300 based BCI are not always practical in real applications. The results showed that this methodology is favorable for the single trial analysis of the P300 event related potential for the disabled. Further research is warranted to achieve additional improvements in the single trial classification accuracies to the levels adequate for use in real applications.

I. Introduction

People interact with the environment through verbal and nonverbal means. However, neurological disorders like motor neuron diseases may impair this interaction as they prevent voluntary muscular activities [1]. Provided that the cognitive ability is not affected by these disorders, a direct communication channel between a brain and an external device enables nonmuscular interaction with the environment using only cognitive functions. Brain computer interface (BCI), which involves the acquisition of the brain activity using a neuroimaging technology followed by its analysis using preprocessing, feature extraction and classification operations, provides such a channel. Electroencephalogram (EEG) is a neuroimaging technology commonly used to acquire brain activity for BCI [2], [3] due to its noninvasive nature, low cost and ease of use [4]. One of the most popular features of EEG utilized in BCI is the P300 event related potential (P300 ERP) [5], [6]. An advantage of the utilization of the P300 ERP over other EEG features in BCI is that the P300 ERP does not require any training since it is an automated response [7].