Brain Computer Interface (BCI) speller is a typical BCI-based application to help paralyzed patients express their thoughts. This paper proposed a novel motor imagery based BCI speller with Oct-o-spell paradigm for word input. Furthermore, an intelligent input method was used for improving the performance of the BCI speller. For the English word spelling experiment, we compared synchronous cont...

A visual speller is a brain–computer interface that empowers users with limitedmotor functionality to input text into a computer by measuring their electroencephalographic responses to visual stimuli. Most prior research on visual spellers has focused on input of alphabetic text. Adapting a speller for other types of segmental or syllabic script is straightforward because such scripts comprise ...

OBJECTIVE Despite numerous examinations of factors affecting P300 speller performance, the impact of stimulus presentation parameters remains incompletely understood. This study examines the effects of four distinct stimulus presentation parameters (stimulus-off time [ISI(∗)], interstimulus interval [ISI], flash duration, and flash-duration:ISI ratio) on the accuracy and efficiency of the P300 ...

The goal of this study was to develop a hybrid mental speller that can effectively prevent unexpected typing errors in the steady-state visual evoked potential (SSVEP)-based mental speller by simultaneously using the information of eye-gaze direction detected by a low-cost webcam without calibration. In the implemented hybrid mental speller, a character corresponding to the strongest SSVEP resp...

The past 20 years have witnessed unprecedented progress in brain-computer interfaces (BCIs). However, low communication rates remain key obstacles to BCI-based communication in humans. This study presents an electroencephalogram-based BCI speller that can achieve information transfer rates (ITRs) up to 5.32 bits per second, the highest ITRs reported in BCI spellers using either noninvasive or i...

This study compared a conventional P300 speller brain-computer interface (BCI) to one used in conjunction with a predictive spelling program. Performance differences in accuracy, bit rate, selections per minute, and output characters per minute (OCM) were examined. An 8×9 matrix of letters, numbers, and other keyboard commands was used. Participants (n = 24) were required to correctly complete ...

There is evidence that conventional visual brain-computer interfaces (BCIs) based on event-related potentials cannot be operated efficiently when eye movements are not allowed. To overcome this limitation, the aim of this study was to develop a visual speller that does not require eye movements. Three different variants of a two-stage visual speller based on covert spatial attention and non-spa...

Eye typing provides a means of communication that is useful for people with disabilities which prevent using their hands for text entry. In this paper, we describe the development of the prototype gaze-controlled speller and discuss its experimental evaluation. Using scrollable virtual keyboard interface, the text input speed of 1.2 wpm was achieved. Keywords—gaze tracking; gaze writing; eye ty...

This paper reports work carried out to develop a speller for Spanish at Microsoft Corporation, discusses the technique for isolatedword error correction used by the speller, provides general descriptions of the error data collection and error typology, and surveys a variety of linguistic considerations relevant when dealing with a world language spread over several countries and exposed to diff...

The P300 speller is one of the BCI applications, which allows users to select letters just by thoughts. However, due to the low signal-to-noise ratio of the P300, signal averaging is often performed, which improves the spelling accuracy but degrades the spelling speed. The authors have proposed reliability-based automatic repeat request (RB-ARQ) to ease this problem. RB-ARQ could be enhanced wh...