Hypothesis
A single experimental task could measure both the error-related negativity in EEG and pain-related avoidance behaviour, letting the two research fields be joined to test whether larger ERN amplitudes predispose people to avoid pain.
What failed
Across 12 participants and six successive task versions, no version elicited both the needed error-related negativity and avoidance behaviour; the manuscript documents each version's results and shortcomings rather than a working paradigm.
Broken assumption
The ERN and pain-avoidance paradigms can be merged into one task without each losing what makes it work.
Why
The authors describe the difficulty of guiding participants into the intended behaviour without their responding to the guidance itself, so that performance is natural yet tightly constrained, and the problems specific to each version.
From the published paper: Traxler et al. Journal of Trial and Error, 2020. ↗CC BY