Dose effects will be explored in this study, with participants randomised to one of four conditions: (i) 10-session Attentional Modification Group , (ii) 10-session Attentional Control Group, (iii) 18-session Attentional Modification Group, and (iv) 18-session Attentional Control Group. The primary outcome measures are pain intensity and pain interference, and secondary outcome measures include anxiety, depression, pain-related fear and sleeping impairment, including engagement to and satisfaction with the online visual-probe training task. It is hypothesized that participants receiving ABM training will show significantly greater reductions in pain and pain-related distress compared to participants receiving placebo training. Dose effects will be investigated in an exploratory manner.