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Conference Paper: Spurious signal detection and delusions of reference in first-episode schizophrenia

TitleSpurious signal detection and delusions of reference in first-episode schizophrenia
Authors
Issue Date2012
PublisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/schres
Citation
The 3rd Biennial Schizophrenia International Research Conference, Florence, Italy, 14–18 April 2012. In Schizophrenia Research, 2012, v. 136 n. S1, p. S337, poster no.157 How to Cite?
AbstractBackground: Delusions of reference (DOR) are a group of highly prevalent psychotic symptoms. In DOR, patients experience attentional capture by certain otherwise neutral aspects in the environment, which were regarded as self-referential. Theoretically, aberrant salience as a result of excessive dopamine firing may lead to spurious signal detection in patients with DOR. We test the hypothesis that patients presenting with and DOR have increased false alarms in a visual and an auditory signal detection task, compared with patients not experiencing the symptom and with healthy controls. Methods: A total of 32 patients with first-episode schizophrenia (mean age 24.3±6.9 years, 19 men) and 17 healthy controls (mean age 24.7±7.7 years, 9 men) were recruited. Controls and patients were matched in age, sex and education. Patients were further divided into a DOR group (n=15) and a non-DOR group (n=17). DOR was assessed using the Ideas of Reference Interview Scale (IRIS). Spurious signal detection was tested using the randomized and sequential Contour Integration Test (Field, Hayes, and Hess 1993) for visual processing and the Babble Task (Hoffman et al, 2007) for auditory processing. Performance was compared between groups using ANOVA and post-Hoc analysis. Signal detection analyses were carried out to differentiate between genuine spurious signal detection and response bias. Relationship between IRIS scores and false alarm rates was explored. Results: Spurious signal detection was observed in both DOR groups and healthy controls in low signal-to-noise trials. In the Contour Integration Test, patients with DOR were more likely to detect spurious signals particularly when the stimuli were presented at a moderate signaltonoise ratio compared with the other two groups (p<0.01), with an effect size of 1.11 (Cohen’s d). False alarms are correlated with DOR severity (r=0.39, p<0.01). All three groups demonstrated good sensitivity and conservative response in signal detection. A similar trend was seen in the Babble Task. Discussion: Spurious signal detection is a common phenomenon under noisy conditions, which can be elicited also in healthy subjects. In DOR, there appears to be increased spurious signal detection, at a moderate signal-to-noise ratio. This observation cannot be accounted for by a general decline in task performance or a more liberal response bias, suggesting genuine false detection of signals in patients with DOR. This study provided initial findings for further investigation into the neurocognitive substrates of DOR.
Persistent Identifierhttp://hdl.handle.net/10722/160405
ISSN
2015 Impact Factor: 4.453
2015 SCImago Journal Rankings: 2.304

 

DC FieldValueLanguage
dc.contributor.authorWong, GHYen_US
dc.contributor.authorTao, Hen_US
dc.contributor.authorHe, Zen_US
dc.contributor.authorChang, WCen_US
dc.contributor.authorChan, KWen_US
dc.contributor.authorHui, CLMen_US
dc.contributor.authorXue, Zen_US
dc.contributor.authorLiu, Zen_US
dc.contributor.authorChen, EYHen_US
dc.date.accessioned2012-08-16T06:09:58Z-
dc.date.available2012-08-16T06:09:58Z-
dc.date.issued2012en_US
dc.identifier.citationThe 3rd Biennial Schizophrenia International Research Conference, Florence, Italy, 14–18 April 2012. In Schizophrenia Research, 2012, v. 136 n. S1, p. S337, poster no.157en_US
dc.identifier.issn0920-9964-
dc.identifier.urihttp://hdl.handle.net/10722/160405-
dc.description.abstractBackground: Delusions of reference (DOR) are a group of highly prevalent psychotic symptoms. In DOR, patients experience attentional capture by certain otherwise neutral aspects in the environment, which were regarded as self-referential. Theoretically, aberrant salience as a result of excessive dopamine firing may lead to spurious signal detection in patients with DOR. We test the hypothesis that patients presenting with and DOR have increased false alarms in a visual and an auditory signal detection task, compared with patients not experiencing the symptom and with healthy controls. Methods: A total of 32 patients with first-episode schizophrenia (mean age 24.3±6.9 years, 19 men) and 17 healthy controls (mean age 24.7±7.7 years, 9 men) were recruited. Controls and patients were matched in age, sex and education. Patients were further divided into a DOR group (n=15) and a non-DOR group (n=17). DOR was assessed using the Ideas of Reference Interview Scale (IRIS). Spurious signal detection was tested using the randomized and sequential Contour Integration Test (Field, Hayes, and Hess 1993) for visual processing and the Babble Task (Hoffman et al, 2007) for auditory processing. Performance was compared between groups using ANOVA and post-Hoc analysis. Signal detection analyses were carried out to differentiate between genuine spurious signal detection and response bias. Relationship between IRIS scores and false alarm rates was explored. Results: Spurious signal detection was observed in both DOR groups and healthy controls in low signal-to-noise trials. In the Contour Integration Test, patients with DOR were more likely to detect spurious signals particularly when the stimuli were presented at a moderate signaltonoise ratio compared with the other two groups (p<0.01), with an effect size of 1.11 (Cohen’s d). False alarms are correlated with DOR severity (r=0.39, p<0.01). All three groups demonstrated good sensitivity and conservative response in signal detection. A similar trend was seen in the Babble Task. Discussion: Spurious signal detection is a common phenomenon under noisy conditions, which can be elicited also in healthy subjects. In DOR, there appears to be increased spurious signal detection, at a moderate signal-to-noise ratio. This observation cannot be accounted for by a general decline in task performance or a more liberal response bias, suggesting genuine false detection of signals in patients with DOR. This study provided initial findings for further investigation into the neurocognitive substrates of DOR.-
dc.languageengen_US
dc.publisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/schres-
dc.relation.ispartofSchizophrenia Researchen_US
dc.titleSpurious signal detection and delusions of reference in first-episode schizophreniaen_US
dc.typeConference_Paperen_US
dc.identifier.emailWong, GHY: ghywong@hku.hken_US
dc.identifier.emailChang, WC: changwc@hku.hken_US
dc.identifier.emailChan, KW: kwsherry@hku.hken_US
dc.identifier.emailHui, CLM: christyh@hkucc.hku.hken_US
dc.identifier.emailChen, EYH: eyhchen@hku.hken_US
dc.identifier.authorityChang, WC=rp01465en_US
dc.identifier.authorityChan, KW=rp00539en_US
dc.identifier.authorityChen, EYH=rp00392en_US
dc.identifier.doi10.1016/S0920-9964(12)70989-1-
dc.identifier.hkuros204596en_US
dc.identifier.hkuros200923-
dc.identifier.volume136en_US
dc.identifier.issueS1-
dc.identifier.spageS337, poster no.157en_US
dc.identifier.epageS337, poster no.157en_US
dc.publisher.placeNetherlands-

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