Skip to main content
. Author manuscript; available in PMC: 2014 Feb 19.
Published in final edited form as: Eur J Pain. 2013 Mar 7;17(9):1374–1384. doi: 10.1002/j.1532-2149.2013.00300.x

Figure 1.

Figure 1

Experimental paradigm and time course of the conditioning experiment. Experimental paradigm (top): Visual cues predicted exposure to painful heat stimulation. Painful stimulation was delivered at a low temperature (LT) or at a higher, more painful temperature (HT). One visual cue (here: triangle) was consistently followed by a LT. Another cue (here: square) was followed by LT or HT. LF: low fear/ pain signal (CS−); HF: high fear/pain signal (CS+ low or CS+ high). The conditioned stimuli were presented during a variable amount of time (8 to 15 s) in order to increase the unpredictability of the unconditioned stimuli. The duration of the exposure to heat stimulation was 6 s. Self-reported fear and pain ratings were assessed in the intertrial intervals of 30 s. CS, conditioned stimulus; US, unconditioned stimulus.