Auditory sustained attention in schizophrenia: a comparison of the Continuous Performance Test and the Pigache Attention Task.

An auditory version of the Continuous Performance Test (CPT) was compared with the Pigache Attention Task (PAT) to evaluate relative sensitivities in schizophrenia. Digits spoken seamlessly for 5 min required a button-press response to each of 50 targets. Diotic and dichotic event rates were 1/s for the CPT and 0.5/s and 2/s for the PAT. 'Correct' responses were restricted to the interstimulus interval (CPT) or to longer intervals (PAT). This study demonstrated that the CPT method of scoring is invalid since significant numbers of late responses counted as both omission and commission errors. The CPT was significantly easier than the PAT, which provided a more appropriate range of difficulty. The PAT again discriminated between healthy subjects and schizophrenic patients.