Abstract
Key words Information processing models are influenced by the information sciences and by computer technology, which progressed in the 1960s and 1970s. During the last decade these models have formed the theoretical basis for much of the experimental research on cognitive dysfunctions in psychiatric patients. An essential element in all of these models is that information is processed in several discrete stages. Different experimental paradigms have been developed in order to tap information about the processes taking place in each of these stages. Most of the research so far on pathological groups has been done on schizophrenic patients. Some deficits found in schizophrenics seem to be symptom-related. This is the case with performance deficits on the Continuous Performance Test with low processing load. Other dysfunctions might be vulnerability indicators, such as deficit performance on the forced choice Span of Apprehension task and the Continuous Performance Test with high momentary processing load, backward masking, serial recall for items that involve active rehearsal, and eye movement dysfunctions. However, information processing deficits do not seem to be specifically related to schizophrenia. Deficits can be found in other psychiatric syndromes too, especially in manic patients. Generally speaking, the dysfunctions emerge in a milder form in nonschizophrenic patients.