Figure 4
![Figure 4](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1741-7007-4-25/MediaObjects/12915_2006_Article_80_Fig4_HTML.jpg)
N1m amplitude as a function of choline. Linear regression plot of the amplitude of the first N1m vs. choline-containing compounds (Cho) (R 2 = 0.287, F(1,13), p = 0.040). The 95% confidence intervals are represented by dashed lines. The insert shows the normal probability plot of the residuals, indicating that the errors are normally distributed. IU, institutional unit.