(C)overt attention and visual speller design in an ERP-based brain-computer interface

By Matthias Sebastian Treder, Benjamin Blankertz. Behavioral and Brain Functions, 2010

388 citations recorded by the source corpus.

BackgroundIn a visual oddball paradigm, attention to an event usually modulates the event-related potential (ERP). An ERP-based brain-computer interface (BCI) exploits this neural mechanism for communication. Hitherto, it was unclear to what extent the accuracy of such a BCI requires eye movements (overt attention) or whether it is also feasible for targets in the visual periphery (covert attention). Also unclear was how the visual design of the BCI can be improved to meet peculiarities of peripheral vision such as low spatial acuity and crowding.MethodHealthy participants (N = 13) performed a copy-spelling task wherein they had to count target intensifications. EEG and eye movements were recorded concurrently. First, (c)overt attention was investigated by way of a target fixation condition and a central fixation condition. In the latter, participants had to fixate a dot in the center of the screen and allocate their attention to a target in the visual periphery. Second, the effect of visual speller layout was investigated by comparing the symbol Matrix to an ERP-based Hex-o-Spell, a two-levels speller consisting of six discs arranged on an invisible hexagon.ResultsWe assessed counting errors, ERP amplitudes, and offline classification performance. There is an advantage (i.e., less errors, larger ERP amplitude modulation, better classification) of overt attention over covert attention, and there is also an advantage of the Hex-o-Spell over the Matrix. Using overt attention, P1, N1, P2, N2, and P3 components are enhanced by attention. Using covert attention, only N2 and P3 are enhanced for both spellers, and N1 and P2 are modulated when using the Hex-o-Spell but not when using the Matrix. Consequently, classifiers rely mainly on early evoked potentials in overt attention and on later cognitive components in covert attention.ConclusionsBoth overt and covert attention can be used to drive an ERP-based BCI, but performance is markedly lower for covert attention. The Hex-o-Spell outperforms the Matrix, especially when eye movements are not permitted, illustrating that performance can be increased if one accounts for peculiarities of peripheral vision.

Subfields: Cognitive Neuroscience, Human-Computer Interaction

View Paper: https://www.semanticscholar.org/paper/b048d6ab1b63b0ab3c1adcce69e88ea2577156d2

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Cognitive Neuroscience

In Human-Computer Interaction

Citations in the corpus

P300 brain computer interface: current challenges and emerging trends (2012, methodology): “…can be used for a wide range of different functions and can work with disabled users in home settings (Kübler et al., 2009; Sellers et al., 2010; Kleih et al., 2012), although some concerns about gaze shifting have emerged (Allison et al., 2008; Brunner et al., 2010; Treder and Blankertz, 2010).”
Brain–Computer Interface Spellers: A Review (2018, methodology): “These two GUIs were developed to be compared with the Hex-O-Spell ERP in [105] for gaze-independent BCI spellers.”
Brain Computer Interfaces, a Review (2012, background): “A spelling rate of 10 words per minute can be obtained with unimpaired eye movement, by means of an eyetracker [260].”
The Berlin Brain–Computer Interface: Non-Medical Uses of BCI Technology (2010, neutral): “…al., 2008; McFarland et al., 2008; Hwang et al., 2009; Williamson et al., 2009; Höhne et al., 2010; Schaefer et al., 2010; Schreuder et al., 2010; Treder and Blankertz, 2010) and data analysis technology (Parra et al., 2005, 2008; Dornhege et al., 2007b; Lotte et al., 2007; Blankertz et al.,…”
Brain-computer interfacing using modulations of alpha activity induced by covert shifts of attention (2011, background): “P300speller), evidence accumulates that BCI control is efficient only when the target symbol is fixated with the eyes [1-3].”