Structure of an example trial.

<p>After a delay of either 300 ms (short lead interval) or 3500–4500 ms (long lead interval) relative to picture onset, startle was elicited by a 50-ms burst of white noise (startle probe). In one third of trials no startle probe was presented. After picture offset, participants had to respond to a smiley symbol (response cue) by indicating a match or mismatch to the expression of the preceding face picture. ITI: Inter-trial interval. (The individuals whose photographs were used for the morphed image shown in this picture have given written informed consent, as outlined in PLOS consent form, to publish these details).