Schematic representation of the color-discrimination task (experiment 4).

<p>Each trial started with the presentation of a grey central target that participants had to touch and hold for a variable period. After a variable delay (stimulus onset asynchrony, SOA) a grey peripheral target appeared and participants were asked either to touch it if it was printed in green (go-trials) or to stay still if it was printed in red (no go trials; see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035403#s2" target="_blank">Methods</a> for more details).