A psychobiological model of the pathogenesis of schizophrenic symptoms.

Schizophrenic symptoms are non-specific and are modifiable by unspecific drugs, by environmental input and 'spontaneously'. An information-theory-based model of their pathogenesis is presented. The model is based on data and theories which suggest memory-driven and state-dependent brain operations for the organization of human behavior in normal or in psychopathological states. The data are integrated in the concept of EEG-defined functional states of the brain with state-dependent information processing. The brain's functional state is multifactorially defined, reflects at each moment the memory storages accessible to the operations of information processing and is continuously readjusted to the demands made on the organism by current received information as estimated by the cerebral mechanisms of initiation of the orienting reaction and of its 'habituation'. Major conclusions of evoked potentials and of EEG-reactivity studies on information processing anomalies in schizophrenia integrated into the model suggest the following: schizophrenic symptoms reflect the behavioral manifestations of brain's information processes which have access to memory storages which contain mnemonic representations of skills and of cognitive-emotional coping strategies which are inadequate to recognize the age- and state-corresponding significance of the current information for the organism.