A novel brain-computer interface based on the rapid serial visual presentation paradigm

Abstract

Most present-day visual brain computer interfaces (BCIs) suffer from the fact that they rely on eye movements, are slow-paced, or feature a small vocabulary. As a potential remedy, we explored a novel BCI paradigm consisting of a central rapid serial visual presentation (RSVP) of the stimuli. It has a large vocabulary and realizes a BCI system based on covert non-spatial selective visual attention. In an offline study, eight participants were presented sequences of rapid bursts of symbols. Two different speeds and two different color conditions were investigated. Robust early visual and P300 components were elicited time-locked to the presentation of the target. Offline classification revealed a mean accuracy of up to 90% for selecting the correct symbol out of 30 possibilities. The results suggest that RSVP-BCI is a promising new paradigm, also for patients with oculomotor impairments.

How stimulation speed affects Event-Related Potentials and BCI performance

“…Most of these approaches are based on Event-Related Potentials (ERPs), which are the EEG responses triggered by a perceived event or stimulus. Various paradigms were proposed using the visual [1] or auditory [2], [3], [4] modality of stimulation. Most of those ERP paradigms follow the oddball principle of rare target and frequent non-target events.…”

“…The SOA specifies the time between the onsets of two consecutive stimuli. Most BCI paradigms are applied with a SOA value between 83 ms [1] and 500 ms [9]. Comparing the visual BCI performance of two SOA levels (175 ms and 350 ms), Sellers et al [10] the choice of SOA highly affects the BCI performance, concluding that "it appears to be worthwhile to test multiple ISI values and thereby determine the optimal value for each user".…”

Reliability of brain computer interface language sample transcription procedures

“…For example, several studies have compared user performance across multiple P300 spellers with different keyboard configurations on copy-spelling tasks [12][13][14]. Some studies have also compared user performance across multiple P300 spellers when users spontaneously generated short messages in a free-spelling phase [13][14], but the production of spontaneous messages has been limited to no more than one sentence per subject.…”

“…Current evidence indicates limitations in accounting for the user's communication competence with the BCI system by only measuring speed and/or accuracy [6][7][8][9][10][11][12][13][14][15][16]. In addition, the copy-spelling task [9][10][11][12][13][14][15][16] has inherent limitations for evaluating the effectiveness of expressive language performance in either structured or unstructured communication environments.…”

“…In addition, the copy-spelling task [9][10][11][12][13][14][15][16] has inherent limitations for evaluating the effectiveness of expressive language performance in either structured or unstructured communication environments. Quantitative performance data in terms of language-dependent variables (e.g., vocabulary frequency, mean length utterance) and speed-dependent variables (e.g., average and peak communication rate) are critical to optimize the effectiveness of AAC systems in both the research laboratory and clinical settings.…”