Nature Communications 4: Article number: 1749 (2013); Published 23 April 2013; Updated 27 August 2013.

In this Article, there are errors in the labelling of the x axes in Fig. 3. The labels ‘−2’ and ‘2’ in panels b–d should have been ‘−20’ and ‘20’, respectively. The correct version of this figure appears below.

Figure 3
figure 1