Figure 1. Experimental procedure: after resting for 10 min, subjective stress and CPM (conditioned pain modulation test) were measured. The subjective stress was rated on an analogic visual analog scale (0 = no stress and 10 = most intense stress imaginable). Sequential CPM protocol was performed by applying pressure pain threshold on masseter muscle as test stimulus and immersion of hand in hot water bath as conditioning stimulus. Two trial of PASAT was followed by post-stress task measures.