Is it a painful error? The effect of unpredictability and intensity of punishment on the error-related negativity, and somatosensory evoked potentials

We examined how predictable and unpredictable punishment intensity contingent on error commission modulated ERN amplitudes. We recorded the ERN in 35 healthy volunteers performing the Eriksen flanker task. Errors were punished with predictable nonpainful, painful or unpredictable electrical stimulation. Furthermore, we investigated trait anxiety. We observed that ERN amplitudes did not differ across conditions, nor were there significant effects of anxiety. In contrast, we found that predictable painful punishments led to smaller Error Positivity (Pe). The effects of predictability and intensity were present in Somatosensory Evoked Potentials elicited by the punishments. N1 amplitudes were increased for painful compared to nonpainful stimulation, and P2/P3 amplitudes for painful compared to nonpainful, and for unpredictable compared to predictable stimulation. We suggest that unpredictability and increased painfulness of punishments enhance the potential motivational significance of the errors, but do not potentiate ERN amplitudes beyond the ones elicited by errors punished with predictable nonpainful stimulation.