Objective behavior associated with an "ordinary" mild headache: a surprising failure of pain onset to signal self-protective or self-regulatory behavior.

OBJECTIVE: The goal of this study was to determine whether onset of an "ordinary" headache initiated self-protective behavior or self-regulation, as indexed by a reduction in effort expenditure.
METHODS: A nonclinical sample was employed. The ambition and performance accuracy of a headache-developing group (n = 23) and a sex-matched, headache-free group (n = 23) was compared during a series of mental arithmetic problems. Embedded within the series of math problems was a task involving recall of a stressor previously found to induce headache in many subjects.
RESULTS: Onset of mild head pain did not lead to effort conservation; instead, heightened ambition appeared to characterize the headache-developing participants before as well as after headache onset. Headache-developing subjects also displayed a performance accuracy deficit.
CONCLUSIONS: The data suggest unusually ambitious, effortful task engagement may contribute to the onset of mild "ordinary" headache. This possibility requires further examination under other controlled conditions as well as in the natural environment.