Lexical knowledge degradation in schizophrenia

This study documents a severe picture naming impairment in a series of 22 c hronically hospitalised schizophrenics. The pattern and level of naming imp airment were comparable in degree and type to that seen neurological patien ts with left hemisphere lesions. This deficit was further examined to deter mine whether it conformed to a disorder affecting access to the lexical rep resentations or some degradation of the stored representations themselves. Patient naming was examined twice (18 months apart) for evidence of consist ency and for word frequency effects. The pattern of individual patient perf ormance on these criteria showed that the majority had storage disorders; a ccess disorders alone occurred in only a small minority of patients. A subs et of 11 of the same patients that were tested on three occasions (across 3 0 months) showed the same pattern but further indicated that when access pr oblems are present, they reflect difficulty with deliberate, rather than au tomatic, access to the lexicon. (C) 2000 Elsevier Science B.V. All rights r eserved.