ental effort. Archnws of General Psychiatry, 43, 126-135. "Flerricss, E. (1985). Positive and negative symptoms and Jackson. A conceptual history. Architxs of Genend Psychiatry, 42, 95-97. RIGHTS 4?. EFTA_R1_01956836 EFTA02674724 Bader, FL & Goldberg, E. (1987). Motor perseveration in schizo- phrenia. Archives of Clini