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Many studies reported that ERP-based BCIs can provide communication for some people with amyotrophic lateral sclerosis (ALS). ERP-based BCIs often present characters within a matrix that occupies the center of the visual field. However, several studies have identified some concerns with the matrix-based approach. This approach may lead to fatigue and errors resulting from flashing adjacent stimuli, and is impractical for users who might want to use the BCI in tandem with other software or feedback in the center of the monitor. In this paper, we introduce and validate an alternate ERP-based BCI display approach. By presenting stimuli near the periphery of the display, we reduce the adjacency problem and leave the center of the display available for feedback or other applications. Two ERP-based display approaches were tested on 18 ALS patients to: (1) compare performance between a conventional matrix speller paradigm (Matrix-P, mean visual angle 6°) and a new speller paradigm with peripherally distributed stimuli (Peripheral-P, mean visual angle 8.8°); and (2) assess performance while spelling 42 characters online continuously, without a break. In the Peripheral-P condition, 12 subjects attained higher than 80% feedback accuracy during online performance, and 7 of these subjects obtained higher than 90% accuracy. The experimental results showed that the Peripheral-P condition yielded performance comparable to the conventional Matrix-P condition (p > 0.05) in accuracy and information transfer rate. This paper introduces a new display approach that leaves the center of the monitor open for feedback and/or other display elements, such as movies, games, art, or displays from other AAC software or conventional software tools.

Purpose: To assess the change in the macular layers in the fellow eyes of unilateral retinal vein occlusion (RVO) patients and to evaluate whether certain layers are more affected based on RVO type. Methods: This retrospective study included 87 fellow eyes of patients with unilateral RVO (26 central, 61 branch) and 105 eyes of 105 subjects without RVO. Spectral domain optical coherence tomography was used for automatized retinal segmentation. The thicknesses of retinal nerve fiber layer (RNFL), ganglion cells, inner plexiform, inner nuclear, outer plexiform, outer nuclear, photoreceptor layers, overall inner retinal layers and retinal pigment epithelium (RPE) were documented. Results: Inner plexiform layer was thinner in inferior sector in RVO group compared with the control group (p = 0.047). The subgroup analysis showed that the retina was thinner in RVO group compared with the controls without systemic diseases in some sectors of the following layers: inferior retina, RNFL, ganglion cell layer, inner plexiform layer, inner retinal layers and RPE (p < 0.05). Retinal thickness was decreased in the fellow eyes of branch RVO group compared to that in the central RVO group in the some sectors (p < 0.05). Conclusions: The fellow eyes of unilateral RVO patients did not show major structural differences compared with the controls; however, they revealed significant sectoral thinning in many retinal layers when compared with the eyes of healthy subjects without systemic diseases. Central macula was thinner in the fellow eyes of patients with branch RVO compared to that in central RVO. © 2018, Springer Nature B.V.