Sensory gating is a process in which the brain’s response to irrelevant and repetitive stimuli is inhibited. Poor P50 gating in those with schizophrenia is typically measured by the ratio or difference score of the event-related potential (ERP) amplitudes in response to a paired click paradigm. Failure to suppress the ERP in response to the second click is thought to reflect a faulty inhibitory system. Oscillatory activity during the inter-click interval in the beta (20-30 Hz) and gamma (30-50 Hz) frequency bands may reflect inhibitory processes initiated by the first click. Paired-auditory stimuli were presented to 131 participants with schizophrenia and 196 healthy controls. P50 ERP amplitude as well as averaged- and single-trial beta (20-30 Hz) and gamma (30-50 Hz) frequency power during the inter-click interval were measured from the CZ electrode site. Data were analyzed using a series of ANOVAs and regression models. The statistical analyses provide evidence that patients with schizophrenia exhibited less evoked beta and gamma power across the delay interval, particularly at the 0-100 ms time point, in response to S1. We found that evoked beta and gamma responses early during the 500 ms delay interval (0-100 ms) are critical in determining the S1 amplitude and extent of P50 gating across the delay interval for both healthy controls and individuals with schizophrenia. Our findings also support a disruption in “gating in” processes in those with schizophrenia. The investigation of oscillatory activity at different time points during the inter-click interval may provide a new framework for studying the mechanisms that support sensory inhibition, and may help researchers and clinicians develop future cognitive training protocols.

LLU Discipline

Clinical Psychology


Clinical Psychology


School of Behavioral Health

First Advisor

Colleen A. Brenner

Second Advisor

Sylvia M. Herbozo

Third Advisor

Grace J. Lee

Degree Name

Doctor of Philosophy (PhD)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Schizophrenia; Sensory Gating; Evoked Potentials



Page Count

xii, 93 p.

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives