title: Influence of environmental contingency history on acquisition of new discriminations by chronic mental patients.
mesh_terms: D002908:Chronic Disease; D004193:Discrimination Learning; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000628:therapy*; D008875:Middle Aged; D008884:Milieu Therapy; D012054:Reinforcement, Psychology; D012919:Social Behavior; D012931:Social Environment; D013808:Therapeutic Community