Interaction plots for the main dependent variables.

<p>Each graph shows the average value of one variable per test phase and per group. The variable names are indicated on the vertical axes. The significance levels indicated by asterisks correspond to the ones given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0098801#pone-0098801-t002" target="_blank">Table 2</a>. Error bars represent standard deviations.