Pre-attentive processing and schizophrenia: animal studies

Rationale. Schizophrenia is characterized by a large variety of cognitive symptoms, among which information processing deficits have been extensively studied. So far, these aspects have been found to be remarkably stable and effective treatment is still lacking. Traditionally, information processing is subdivided into pre-attentive (automatic) and attentive processing. Pre-attentive processing refers to the early stages of information processing before conscious attention sets in. Two paradigms most often used to investigate pre-attentive processing are prepulse inhibition and auditory (or P-50) gating. The advantage of these two paradigms is that they can be used in humans and animals with virtually identical methods. Objective. The present paper aims to highlight the similarities and differences between these two aspects of pre-attentive processing, and to illustrate their usefulness for studying such cognitive deficits in schizophrenia. Methods. We evaluated the available animal literature, focusing on both pharmacological and non-pharmacological methods for altering pre-attentive gating. Results. Even though prepulse inhibition has been investigated much more than P-50 gating, the available literature shows that there are many more differences than similarities between the two paradigms. Conclusions. Prepulse inhibition and P-50 gating are mediated through different neuronal mechanisms and therefore both paradigm offer the possibility of developing novel therapeutic targets for the cognitive deficits in schizophrenia. However, such an approach will only be successful when a further integration between clinical and pre-clinical research takes place.