Experiment condition (predictable or unpredictable pain condition)
1 = Pred
2 = Unpred

Experimental or control group
1 = exp
2 = con

4 groups: Predictable experimenta;Predictable control: Unpredictable experimental; Unpredictable control
1.00 = P_ex
2.00 = P_con
3.00 = U_ex
4.00 = U_con