Fig. 6.

The analysis reported in Fig. 4 was repeated with different epoch lengths. For each combination of measures, just the μ value reported in that figure has been depicted here. The μ values shown in Fig. 4 are therefore the same as those shown for the 20-s epoch length here. The approximate cut-offs for values that were found to differ significantly from zero have been indicated with a dashed red line. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)