Top panels show percentage of total responses made on the drug-appropriate lever. Bottom panels show rate of responding in responses per second (r/s). Sample size of MDMA n=13, 4-methylethcathinone (4-MEC), flephedrone, ethylone n=6, methcathinone, 4-methylmethcathinone (4-FMC, mephedrone) n=7, 3-fluoromethcathinone (3-FMC) n=8, pentedrone n=9, unless otherwise shown. Ctrl indicates vehicle and training drug control values. * indicates response rate different from vehicle control (p < 0.05).