Fig. 2From: Enhancement of pain inhibition by working memory with anodal transcranial direct current stimulation of the left dorsolateral prefrontal cortexExperimental design. The experimental protocol comprised five counterbalanced conditions, including the 0-back, 2-back, pain, 0-back with pain and 2-back with pain conditions. This experimental protocol was performed twice during each session, once to establish a pre-transcranial direct current stimulation (tDCS) baseline and once during tDCS. The same order was used for the sham and anodal tDCS sessions for a given participant. Each condition contained 60 trials within 3.5 min. Participants had to verbally rate their average pain and their pain-related anxiety using a numerical rating scale (NRS; range 0–100) after each condition comprising painful stimuliBack to article page