Hostname: page-component-6766d58669-mzsfj Total loading time: 0 Render date: 2026-05-20T16:34:50.745Z Has data issue: false hasContentIssue false

Visual masking by object substitution in schizophrenia

Published online by Cambridge University Press:  16 November 2010

M. F. Green*
Affiliation:
VA Desert Pacific Mental Illness Research, Education, and Clinical Center, Los Angeles, CA, USA Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, CA, USA
J. K. Wynn
Affiliation:
VA Desert Pacific Mental Illness Research, Education, and Clinical Center, Los Angeles, CA, USA Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, CA, USA
B. Breitmeyer
Affiliation:
Department of Psychology, University of Houston, Houston, TX, USA
K. I. Mathis
Affiliation:
VA Desert Pacific Mental Illness Research, Education, and Clinical Center, Los Angeles, CA, USA
K. H. Nuechterlein
Affiliation:
Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, CA, USA Department of Psychology, UCLA, Los Angeles, CA, USA
*
*Address for correspondence: M. F. Green, Ph.D., 300 Medical Plaza, Rm 2263, Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, CA 90095–6968, USA. (Email: mgreen@ucla.edu)

Abstract

Background

Schizophrenia patients demonstrate impairment on visual backward masking, a measure of early visual processing. Most visual masking paradigms involve two distinct processes, an early fast-acting component associated with object formation and a later component that acts through object substitution. So far, masking paradigms used in schizophrenia research have been unable to separate these two processes.

Method

We administered three visual processing paradigms (location masking with forward and backward masking, four-dot backward masking and a cuing task) to 136 patients with schizophrenia or schizoaffective disorder and 79 healthy controls. A psychophysical procedure was used to match subjects on identification of an unmasked target prior to location masking. Location masking interrupts object formation, four-dot masking task works through masking by object substitution and the cuing task measures iconic decay.

Results

Patients showed impairment on location masking after being matched for input threshold, similar to previous reports. After correcting for age, patients showed lower performance on four-dot masking than controls, but the groups did not differ on the cuing task.

Conclusions

Patients with schizophrenia showed lower performance when masking was specific to object substitution. The difference in object substitution masking was not due to a difference in rate of iconic decay, which was comparable in the two groups. These results suggest that, despite normal iconic decay rates, individuals with schizophrenia show impairment in a paradigm of masking by object substitution that did not also involve disruption of object formation.

Information

Type
Original Articles
Copyright
Copyright © Cambridge University Press 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable