Measuring p50 suppression and prepulse inhibition in a single recording session

Objective: Two distinct measures have been used to assess inhibitory gating deficits in schizophrenia patients: P50 suppression and prepulse inhibitio n of the startle response. It remains unclear whether both measures can be assessed in a single testing session. Method: Twelve normal subjects underwent testing in a carefully designed co mbined P50/prepulse inhibition session using stimulus characteristics simil ar to those described in the existing literature. Results: The levels of both P50 suppression and prepulse inhibition obtaine d in the combined session were highly similar to those obtained in independ ent testing of previous cohorts of normal subjects. As in previous experime nts, P50 suppression and prepulse inhibition were not significantly correla ted. Conclusions: Measuring P50 suppression and prepulse inhibition in a single session is feasible and offers a unique opportunity to assess these two dis tinct gating measures contemporaneously in cohorts of normal comparison sub jects and schizophrenia patients, so that temporal shifts in one or both me asures are minimized.