Inhibition of Return in Older Adults with Schizophrenia: Does Age Matter?

By Caili Wu, Paul Dagg, Carol Ward and Maxine Crawford.

Published by The International Journal of Aging and Society

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Inhibition of return (IOR) refers the effect that people are slower to detect a target that appears at the same location of a previous event than when it appears in a new location. Recent studies investigating IOR in patients with schizophrenia have had conflicting results and there is no published study examining IOR in older schizophrenia patients. In an attempt to add clarity IOR in patients with schizophrenia and to probe IOR in older schizophrenia patients, this study examined IOR in young and old patients diagnosed with schizophrenia who are exhibiting severe symptomology and therefore require tertiary mental health care. A typical exogenous cuing paradigm with two stimulus onset asynchronies (SOAs) of 200 and 600 ms was used to observe the typical biphasic effects: an early facilitation and a later IOR. As expected, the control group showed a significant facilitation at 200 ms SOA, and a significant IOR effect at 600 ms SOA for both age groups. In contrast, the patient group showed facilitation at both 200 and 600 ms SOA for both age groups. This result suggests that IOR is absent in patients with schizophrenia and that they exhibit continued facilitation. Moreover, IOR appears to be an age-resistant effect in the control group and the lack of IOR in the patient group is not related to age either. Furthermore, the lack of IOR in patients with schizophrenia was not related to their psychopathology symptoms, cognitive dysfunctions, and overall severity of illness.

Keywords: Inhibition of Return, Schizophrenia, Orienting of Attention, Aging

Aging and Society: An Interdisciplinary Journal, Volume 1, Issue 4, pp.49-60. Article: Print (Spiral Bound). Article: Electronic (PDF File; 960.755KB).

Dr. Caili Wu

Researcher, Hillside Psychiatric Center, Hillside Centre, Interior Health Authority, Kamloops, BC, Canada

Caili Wu is a researcher at Hillside Centre, a newer tertiary mental health facility of Interior Health Authority, British Columbia, Canada. She received her PhD degree in cognitive psychology from State University of New York at Binghamton in 2007. Her research interests include understanding psychiatric characteristics and care needs of patients who require tertiary services, evaluating existing program outcomes, providing information for evidence based decisions, etc. With her research background in cognitive psychology, she is especially interested in examining cognitive impairments in patients with mental illness such as dementia, schizophrenia, and traumatic brain injuries. She has started to apply experimental procedures to explore the various cognitive impairments in people with severe mental disorders. For example, she developed a pilot research project using an experimental procedure to investigate an attentional effect, inhibition of return (IOR), in older patients with schizophrenia. This project was funded by British Columbia Network for Aging Research (BCNAR) 2008 seed grant.

Dr. Paul Dagg

Clinical Director, Psychiatrist, Hillside Psychiatric Center, Hillside Centre, Interior Health Authority; University of British Columbia, Kamloops, BC, Canada

Dr. Carol Ward

Geriatric Psychiatrist, Hillside Psychiatric Center, Hillside Centre, Interior Health Authority; University of British Columbia, Kamloops, BC, Canada

Maxine Crawford

Hillside Centre, Interior Health Authority, Kelowna, BC, Canada