Evidence of reduced ‘cognitive inhibition’ in schizophrenia

Abstract

An experiment is described which investigated cognitive inhibition in schizophrenia. It is noted that both the abnormal and cognitive literatures use the concept of inhibition. Frith (1979) suggests that the more cognitive symptoms of schizophrenia may be due to the failure to limit the current contents of consciousness due to a failure adequately to inhibit the output of preconscious processes. Current thinking in cognitive psychology suggests that in the process of selective attention there is active inhibition of distractor information. A technique used to investigate this is termed negative priming (Tipper, 1985). The general nature of this paradigm is as follows: if a distractor, which has been previously ignored, is subsequently re‐presented, there is an increased reaction time associated with the response, due to inhibition of the information when it was originally a distractor. It was found that inhibition of such distracting information was reduced in schizophrenics. This finding is seen as providing some support for Frith's (1979) theory that the cognitive symptoms of schizophrenia are due to awareness of processes that normally occur preconsciously.