02632nas a2200217   4500008004100000245012200041210006900163260001200232520184800244653004002092653003502132653004402167653001702211100002102228700002102249700001702270700002102287700002102308700002102329856006402350       2019                        eng d00aAn exploration of BCI performance variations in people with amyotrophic lateral sclerosis using longitudinal EEG data0 aexploration of BCI performance variations in people with amyotro  c05/20193 aObjective. Brain-computer interface (BCI) technology enables people to use direct measures of brain activity for communication and control. The National Center for Adaptive Neurotechnologies (NCAN) and Helen Hayes Hospital are studying long-term independent home use of P300-based BCIs by people with amyotrophic lateral sclerosis (ALS). This BCI use takes place without technical oversight, and users can encounter substantial variation in their day-to-day BCI performance. The purpose of this study is to identify and evaluate features in the electroencephalogram (EEG) that correlate with successful BCI performance during home use with the goal of improving BCI for people with neuromuscular disorders. Approach. Nine people with ALS used a P300-based BCI at home over several months for communication and computer control. Sessions from a routine calibration task were categorized as successful (≥70%) or unsuccessful (<70%) BCI performance. The correlation of temporal and spectral EEG features with BCI performance was then evaluated. Main Results. BCI performance was positively correlated with an increase in alpha-band (8-14 Hz) activity at locations PO8, P3, Pz, and P4; and beta-band (15-30 Hz) activity at occipital locations. In addition, performance was significantly positively correlated with a positive deflection in EEG amplitude around 220 ms at frontal mid-line locations (i.e., Fz and Cz). BCI performance was negatively correlated with delta-band (1-3 Hz) activity recorded from occipital locations. Significance. These results highlight the variability found in the EEG and describe EEG features that correlate with successful BCI performance during day-to-day use of a P300-based BCI by people with ALS. These results should inform studies focused on improved BCI reliability for people with neuromuscular disorders.10aamyotrophic lateral sclerosis (ALS)10aBrain-computer interface (BCI)10aLongitudinal Electroencephalogram (EEG)10aP300 speller1 aShahriari, Yalda1 aVaughan, Theresa1 aMcCane, Lynn1 aAllison, Brendan1 aWolpaw, Jonathan1 aKrusienski, Dean  uhttps://iopscience.iop.org/article/10.1088/1741-2552/ab22ea