ordered trials. Distraction task trials were not included in
analyses. MRI data were not analyzed for this report.
Between each trial, participants completed a mental arithmetic
task for 13 seconds. Participants were presented
with a four-digit number and were asked to verbally count
backwards in decrements of seven as quickly and accurately
as possible.
At the end of the entire paradigm, participants were asked
to identify the purpose of the experiment. A response was
counted as correct if the participants in any way identified
pain as the outcome and the pictures as the experimental
variable. This question was designed to account for
demand characteristics in the experiment.