Table 1 The list of inclusion and exclusion criteria

P

- Healthy controls

- Pain-free controls

- Information on any disease

I

- Operant conditioning procedure

- Classical conditioning studies

- Observational learning studies

- Other interventions combined with operant conditioning

C

- No restriction

- Within-subject control

- Between-subject control

- No intervention

- Non-contingent learning

- No conditioning procedure

N/A

O

- Pain measured on any pain scale

N/A

S

- Experimental studies

- Randomized controlled trials

- Published until 2018

- Conference proceedings

- Only abstracts available