Fig 2. Categorical agreement in the detection of the N1 peak (primary outcomes).

The boundaries of the boxes indicate the 25^th and 75^th percentiles, the line within the box marks the median, the whiskers indicate the 10^th and 90^th percentiles and the circles above and below represent outliers (n = 16 for each index). Horizontal lines on top of the bars represent statistically significant post hoc differences between pairings (Student-Newman-Keuls, p < 0.05). p _pos: positive percent agreement, p _neg: negative percent agreement, κ: Cohen’s kappa.