Deficient attentional modulation of startle eyeblink is associated with symptom severity in the schizophrenia spectrum

Patients with schizophrenia-spectrum disorders show deficient prepulse inhibition (PPI) of the startle eyeblink reflex which is thought to reflect an early stage of information processing called automatic sensorimotor gating. They also exhibit deficient attentional modulation of PPI and prepulse facilitation (PPF) of startle which is thought to reflect deficient early and later controlled attentional processing. This is the first study to assess attentional modulation of PPI and PPF in a 3-group schizophrenia-spectrum sample of age- and sex-matched unmedicated schizotypal personality disorder (SPD) and schizophrenia patients, and healthy controls. Participants performed a tone-length judgment task involving attended, ignored, and novel tone prepulses while the acoustic startle eyeblink reflex was measured. Healthy controls showed greater PPI and PPF during the attended prepulses compared with the ignored prepulses. In contrast, both the SPD and schizophrenia patient groups failed to show this pattern, indicating deficient early and later controlled attentional processing. These findings suggest abnormal attentional modulation of PPI and PPF may be a trait-like feature found in patients with schizophrenia-spectrum disorders. Among the schizophrenia-spectrum sample, more deficient PPI during the attended prepulses was associated with greater symptom severity as measured by the total 18-item Brief Psychiatric Rating Scale score.