Behavioral and Cortical Effects during Attention Driven Brain-Computer Interface Operations in Spatial Neglect: A Feasibility Case Study

摘要

FIGURE 1. Visual paradigm and reaction time (RT). (A) Schematic representation of the paradigm presented to spatial neglect (SN) patients. Each trial started with a fixation period (3000 ms) where patients had to gaze at a cross, visible at the center of the screen. Then the cross was replaced by a symbolic cue (300 ms) indicating the to-be-attended location. The covert attention period lasted for 3000–4000 ms; afterward, one of the two to-be-attended locations was highlighted in red (target selection, 100 ms) as online feedback of the classification result. Immediately afterward—in the case of left target—the image started moving toward the center of the screen (target movement, 1000 ms) and it disappeared after 400 ms (target stop). SN patients were required to press a button with their right hand as soon as they perceived the images highlighted in red. (B) Analysis on RT for left covert visuospatial attention (CVSA) task. Distribution of RT for each patient across modality. For each box, median is reported. Box edges represent the 25th and 75th percentile of Individual α-Power (IAP). Student t-test outcomes are annotated in each plot. (C) Scatter plot shows the evolution of RT over time. Results are reported for each patient (in blue, red, and yellow for P1, P2 and P3, respectively). Lines represent the least-squares fit to the scatter plot for each patient. Spearman’s correlation and significance are annotated.