Sham TENS Device
A sham TENS device (BeurerEM80, Beurer GmbH, Ulm, Germany) was used for the conditioning paradigm, which was renamed as a Dermal Nerve Stimulation (DNS) device to avoid possible preconceptions about TENS from interfering with experimental manipulations. Two TENS electrodes were attached vertically on the radial side of the forearm of the nondominant hand. The device itself was switched on as seeing the light would suggest its activation to the participant, but actually, it was never activated; thus, electrical signals were not delivered at any stage of the experiment. This device is not labelled for use under discussion. E-prime version 3.0 (Psychology Software Tools, Pittsburg, PA) was used for presenting the texts “DNS on” and “DNS off” on a monitor screen to indicate the (sham) activation of the DNS device. These texts were presented in purple and yellow, counter-balanced across participants.