The panmodal sensory imprecision hypothesis of schizophrenia: reduced auditory precision in schizotypy

Research on tasks such as pitch discrimination suggests the presence of a panmodal sensory imprecision in schizophrenia: a global deficit in the fidelity of representations. In order to better understand the basis of this deficit, auditory precision was examined in a normal sample varying in schizotypal personality disorder (SPD) symptoms. Experiment 1 reports a significant linear relationship between auditory imprecision and SPD scores. A second experiment on the effects of delay revealed that, as in schizophrenia, this deficit did not reflect an increased rate of decay of the representation. A third experiment used an auditory inspection time task to examine speed of processing using a backward mask to limit exposure duration. No differences in processing speed were found. These results mirror findings in schizophrenia and suggest that the rate of information accumulation into the sensory store is normal, as is the rate of decay of this representation, but that the ultimate fidelity of primary sensory representations is reduced. It is suggested that deficits in the fine structure of representations may be a basic element of vulnerability for schizophrenia.