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Karamaouna P, Zouraraki C, Economou E, Kafetsios K, Bitsios P, Giakoumaki SG. Cold executive function processes and their hot analogs in schizotypy. J Int Neuropsychol Soc 2024; 30:285-294. [PMID: 37750805 DOI: 10.1017/s1355617723000590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
OBJECTIVE To examine cold (based on logical reasoning) versus hot (having emotional components) executive function processes in groups with high individual schizotypal traits. METHOD Two-hundred and forty-seven participants were administered the Schizotypal Personality Questionnaire and were allocated into schizotypal (cognitive-perceptual, paranoid, negative, disorganized) or control groups according to pre-specified criteria. Participants were also administered a battery of tasks examining working memory, complex selective attention, response inhibition, decision-making and fluid intelligence and their affective counterparts. The outcome measures of each task were reduced to one composite variable thus formulating five cold and five hot cognitive domains. Between-group differences in the cognitive domains were examined with repeated measures analyses of covariance. RESULTS For working memory, the control and the cognitive-perceptual groups outperformed negative schizotypes, while for affective working memory controls outperformed the disorganized group. Controls also scored higher compared with the disorganized group in complex selective attention, while both the control and the cognitive-perceptual groups outperformed negative schizotypes in complex affective selective attention. Negative schizotypes also had striking difficulties in response inhibition, as they scored lower compared with all other groups. Despite the lack of differences in fluid intelligence, controls scored higher compared with all schizotypal groups (except from cognitive-perceptual schizotypes) in emotional intelligence; the latter group reported higher emotional intelligence compared with negative schizotypes. CONCLUSION Results indicate that there is no categorical association between the different schizotypal dimensions with solely cold or hot executive function processes and support impoverished emotional intelligence as a core feature of schizotypy.
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Affiliation(s)
- Penny Karamaouna
- Laboratory of Neuropsychology, Department of Psychology, School of Social Sciences, University of Crete, Rethymno, Crete, Greece
- University of Crete Research Center for the Humanities, the Social and Education Sciences (UCRC), University of Crete, Rethymno, Crete, Greece
| | - Chrysoula Zouraraki
- Laboratory of Neuropsychology, Department of Psychology, School of Social Sciences, University of Crete, Rethymno, Crete, Greece
- University of Crete Research Center for the Humanities, the Social and Education Sciences (UCRC), University of Crete, Rethymno, Crete, Greece
| | - Elias Economou
- Laboratory of Experimental Psychology, Department of Psychology, School of Social Sciences, University of Crete, Rethymno, Crete, Greece
| | | | - Panos Bitsios
- Department of Psychiatry and Behavioural Sciences, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Stella G Giakoumaki
- Laboratory of Neuropsychology, Department of Psychology, School of Social Sciences, University of Crete, Rethymno, Crete, Greece
- University of Crete Research Center for the Humanities, the Social and Education Sciences (UCRC), University of Crete, Rethymno, Crete, Greece
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Fouladirad S, Chen LV, Roes M, Chinchani A, Percival C, Khangura J, Zahid H, Moscovitz A, Arreaza L, Wun C, Sanford N, Balzan R, Moritz S, Menon M, Woodward TS. Functional brain networks underlying probabilistic reasoning and delusions in schizophrenia. Psychiatry Res Neuroimaging 2022; 323:111472. [PMID: 35405574 DOI: 10.1016/j.pscychresns.2022.111472] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 02/20/2022] [Accepted: 03/28/2022] [Indexed: 10/18/2022]
Abstract
Delusions in schizophrenia are false beliefs that are assigned certainty and not afforded the scrutiny that normally gives rise to doubt, even under conditions of weak evidence. The goal of the current functional magnetic resonance imaging (fMRI) study is to identify the brain network(s) involved in gathering information under conditions of weak evidence, in people with schizophrenia experiencing delusions. fMRI activity during probabilistic reasoning in people with schizophrenia experiencing delusions (n = 29) compared to people with schizophrenia not experiencing delusions (n = 41) and healthy controls (n = 41) was observed when participants made judgments based on evidence that weakly or strongly matched (or mismatched) with the focal hypothesis. A brain network involved in visual attention was strongly elicited for conditions of weak evidence for healthy controls and patients not experiencing delusions, but this increase was absent for patients experiencing delusions. This suggests that the state associated with delusions manifests in fMRI as reduced activity in an early visual attentional process whereby weak evidence is incorrectly stamped as conclusive, manifestating as a feeling of fluency and misplaced certainty, short-circuiting the search for evidence, and providing a candidate neural process for 'seeding' delusions.
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Affiliation(s)
- Saman Fouladirad
- BC Mental Health and Substance Use Services, Vancouver, BC, Canada; Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Linda V Chen
- BC Mental Health and Substance Use Services, Vancouver, BC, Canada; Faculty of Science, University of British Columbia, Vancouver, BC, Canada
| | - Meighen Roes
- BC Mental Health and Substance Use Services, Vancouver, BC, Canada; Department of Psychology, University of British Columbia, Vancouver, BC, Canada
| | - Abhijit Chinchani
- BC Mental Health and Substance Use Services, Vancouver, BC, Canada; Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Chantal Percival
- BC Mental Health and Substance Use Services, Vancouver, BC, Canada; Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Jessica Khangura
- BC Mental Health and Substance Use Services, Vancouver, BC, Canada; Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Hafsa Zahid
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Aly Moscovitz
- BC Mental Health and Substance Use Services, Vancouver, BC, Canada; Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Leonardo Arreaza
- BC Mental Health and Substance Use Services, Vancouver, BC, Canada; Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Charlotte Wun
- BC Mental Health and Substance Use Services, Vancouver, BC, Canada; Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Nicole Sanford
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Ryan Balzan
- College of Education, Psychology & Social Work, Flinders University, Adelaide, SA, Australia
| | - Steffen Moritz
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Mahesh Menon
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Todd S Woodward
- BC Mental Health and Substance Use Services, Vancouver, BC, Canada; Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
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Karamaouna P, Zouraraki C, Giakoumaki SG. Cognitive Functioning and Schizotypy: A Four-Years Study. Front Psychiatry 2020; 11:613015. [PMID: 33488431 PMCID: PMC7820122 DOI: 10.3389/fpsyt.2020.613015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 12/08/2020] [Indexed: 12/02/2022] Open
Abstract
Although there is ample evidence from cross-sectional studies indicating cognitive deficits in high schizotypal individuals that resemble the cognitive profile of schizophrenia-spectrum patients, there is still lack of evidence by longitudinal/follow-up studies. The present study included assessments of schizotypal traits and a wide range of cognitive functions at two time points (baseline and 4-years assessments) in order to examine (a) their stability over time, (b) the predictive value of baseline schizotypy on cognition at follow-up and (c) differences in cognition between the two time points in high negative schizotypal and control individuals. Only high negative schizotypal individuals were compared with controls due to the limited number of participants falling in the other schizotypal groups at follow-up. Seventy participants (mean age: 36.17; 70% females) were assessed at baseline and follow-up. Schizotypal traits were evaluated with the Schizotypal Personality Questionnaire. We found that schizotypal traits decreased over time, except in a sub-group of participants ("schizotypy congruent") that includes individuals who consistently meet normative criteria of inclusion in either a schizotypal or control group. In these individuals, negative schizotypy and aspects of cognitive-perceptual and disorganized schizotypy remained stable. The stability of cognitive functioning also varied over time: response inhibition, aspects of cued attention switching, set-shifting and phonemic/semantic verbal fluency improved at follow-up. High negative schizotypy at baseline predicted poorer response inhibition and semantic switching at follow-up while high disorganized schizotypy predicted poorer semantic processing and complex processing speed/set-shifting. The between-group analyses revealed that response inhibition, set-shifting and complex processing speed/set-shifting were poorer in negative schizotypals compared with controls at both time points, while maintaining set and semantic switching were poorer only at follow-up. Taken together, the findings show differential stability of the schizotypal traits over time and indicate that different aspects of schizotypy predict a different pattern of neuropsychological task performance during a 4-years time window. These results are of significant use in the formulation of targeted early-intervention strategies for high-risk populations.
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Affiliation(s)
- Penny Karamaouna
- Laboratory of Neuropsychology, Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno, Greece.,University of Crete Research Center for the Humanities, The Social and Educational Sciences (UCRC), University of Crete, Rethymno, Greece
| | - Chrysoula Zouraraki
- Laboratory of Neuropsychology, Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno, Greece.,University of Crete Research Center for the Humanities, The Social and Educational Sciences (UCRC), University of Crete, Rethymno, Greece
| | - Stella G Giakoumaki
- Laboratory of Neuropsychology, Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno, Greece.,University of Crete Research Center for the Humanities, The Social and Educational Sciences (UCRC), University of Crete, Rethymno, Greece
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Vanes LD, Mouchlianitis E, Patel K, Barry E, Wong K, Thomas M, Szentgyorgyi T, Joyce D, Shergill S. Neural correlates of positive and negative symptoms through the illness course: an fMRI study in early psychosis and chronic schizophrenia. Sci Rep 2019; 9:14444. [PMID: 31595009 PMCID: PMC6783468 DOI: 10.1038/s41598-019-51023-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 09/23/2019] [Indexed: 12/14/2022] Open
Abstract
Psychotic illness is associated with cognitive control deficits and abnormal recruitment of neural circuits subserving cognitive control. It is unclear to what extent this dysfunction underlies the development and/or maintenance of positive and negative symptoms typically observed in schizophrenia. In this study we compared fMRI activation on a standard Stroop task and its relationship with positive and negative symptoms in early psychosis (EP, N = 88) and chronic schizophrenia (CHR-SZ, N = 38) patients. CHR-SZ patients showed reduced frontal, striatal, and parietal activation across incongruent and congruent trials compared to EP patients. Higher positive symptom severity was associated with reduced activation across both trial types in supplementary motor area (SMA), middle temporal gyrus and cerebellum in EP, but not CHR-SZ patients. Higher negative symptom severity was associated with reduced cerebellar activation in EP, but not in CHR-SZ patients. A negative correlation between negative symptoms and activation in SMA and precentral gyrus was observed in EP patients and in CHR-SZ patients. The results suggest that the neural substrate of positive symptoms changes with illness chronicity, and that cognitive control related neural circuits may be most relevant in the initial development phase of positive symptoms. These findings also highlight a changing role for the cerebellum in the development and later maintenance of both positive and negative symptoms.
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Affiliation(s)
- Lucy D Vanes
- Wellcome Centre for Human Neuroimaging, University College London, 12 Queen Square, London, WC1N 3AR, United Kingdom.
| | - Elias Mouchlianitis
- Institute of Psychiatry, Psychology and Neuroscience, de Crespigny Park, London, SE5 8AF, United Kingdom
| | - Krisna Patel
- Institute of Psychiatry, Psychology and Neuroscience, de Crespigny Park, London, SE5 8AF, United Kingdom
| | - Erica Barry
- Institute Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY, USA
| | - Katie Wong
- Institute of Psychiatry, Psychology and Neuroscience, de Crespigny Park, London, SE5 8AF, United Kingdom
| | - Megan Thomas
- Institute of Psychiatry, Psychology and Neuroscience, de Crespigny Park, London, SE5 8AF, United Kingdom
| | - Timea Szentgyorgyi
- Institute of Psychiatry, Psychology and Neuroscience, de Crespigny Park, London, SE5 8AF, United Kingdom
| | - Dan Joyce
- Institute of Psychiatry, Psychology and Neuroscience, de Crespigny Park, London, SE5 8AF, United Kingdom
| | - Sukhwinder Shergill
- Institute of Psychiatry, Psychology and Neuroscience, de Crespigny Park, London, SE5 8AF, United Kingdom
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Luk J, Underhill K, Woodward TS. Psychotic Symptoms Predicting Evidence Integration in Schizophrenia. ZEITSCHRIFT FUR PSYCHOLOGIE-JOURNAL OF PSYCHOLOGY 2018. [DOI: 10.1027/2151-2604/a000334] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract. A bias against disconfirmatory evidence (BADE) is a cognitive bias associated with delusions in schizophrenia. Previous studies reporting an association between reduced evidence integration and delusions used a single measure of delusion severity, typically to form patient groups. In the current study we perform an exploratory analysis to investigate whether BADE is specific to delusions or extends to other symptoms of psychosis. To address this, we used constrained principal component analysis (CPCA) on four merged BADE studies on schizophrenia to explore the component structure in the BADE task measures that is predictable from symptoms. A component reflecting evidence integration emerged, and was predicted by delusions as expected, but also by thought disorder. This provides novel methodology for cognitive neuropsychiatric investigations into the underpinnings of the symptoms of schizophrenia by enabling investigators to consider a range of symptoms alongside the one that is the target of their investigation.
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Affiliation(s)
- Jessica Luk
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
- BC Mental Health and Addictions Research Institute, Vancouver, BC, Canada
| | - Kendra Underhill
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
- BC Mental Health and Addictions Research Institute, Vancouver, BC, Canada
| | - Todd S. Woodward
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
- BC Mental Health and Addictions Research Institute, Vancouver, BC, Canada
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White matter changes in treatment refractory schizophrenia: Does cognitive control and myelination matter? NEUROIMAGE-CLINICAL 2018; 18:186-191. [PMID: 29387534 PMCID: PMC5789151 DOI: 10.1016/j.nicl.2018.01.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 01/14/2018] [Indexed: 01/14/2023]
Abstract
Widespread white matter abnormalities have been reported in schizophrenia, a disorder frequently characterised as a dysconnection syndrome. White matter connectivity in schizophrenia has been predominantly investigated using diffusion weighted imaging, with reductions in fractional anisotropy throughout the brain often interpreted as an indicator of abnormal myelination. However, diffusion weighted imaging lacks specificity and as such a number of microstructural factors besides myelin may be contributing to these results. We utilised multicomponent driven equilibrium single pulse observation of T1 and T2 (mcDESPOT) in medicated patients with chronic schizophrenia, stratified by treatment response status, and healthy controls, in order to assess myelin water fraction (MWF) in these groups. In addition, we assessed cognitive control using the Stroop task to investigate how response inhibition relates to myelination in patients and controls. Both treatment resistant (n = 22) and treatment responsive (n = 21) patients showed reduced MWF compared to healthy controls (n = 24) in bilateral fronto-occipital fasciculi, particularly evident in the vicinity of the striatum und extending to the cerebellum, with no difference between patient groups. Patients showed greater reaction time interference on the Stroop task compared to healthy controls, with no difference between patient groups. Stroop interference was significantly negatively correlated with MWF in the corpus callosum across groups, and MWF differences in this region mediated the behavioural group effects on the Stroop task. These findings support the suitability of mcDESPOT as a myelin-specific measure of abnormal connectivity in schizophrenia, and suggest that treatment resistant schizophrenia is not characterised by more severe abnormalities in myelination or cognitive control compared to treatment responsive schizophrenia. Treatment resistant and responsive schizophrenia patients show reduced myelin water fraction compared to healthy controls Myelin water fraction in the corpus callosum is related to performance on a cognitive control task Myelin water fraction in the corpus callosum mediates differences in a cognitive control task between patients and controls
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Woodward TS, Leong K, Sanford N, Tipper CM, Lavigne KM. Altered balance of functional brain networks in Schizophrenia. Psychiatry Res Neuroimaging 2016; 248:94-104. [PMID: 26786152 DOI: 10.1016/j.pscychresns.2016.01.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 11/17/2015] [Accepted: 01/03/2016] [Indexed: 11/18/2022]
Abstract
Activity in dorsal attention (DAN) and frontoparietal (FPN) functional brain networks is linked to allocation of attention to external stimuli, and activity in the default-mode network (DMN) is linked to allocation of attention to internal representations. Tasks requiring attention to external stimuli shift activity to the DAN/FPN and away from the DMN, and optimal task performance depends on balancing DAN/FPN against DMN activity. The current functional magnetic resonance imaging (fMRI) study assessed the balance of DAN/FPN and DMN activity in 13 schizophrenia patients and 13 healthy controls while they were engaged in a task switching Stroop paradigm which demanded internally directed attention to task instructions. The typical pattern of reciprocity between the DAN/FPN and DMN was observed for healthy controls but not for patients, suggesting a reduction in the internally focussed thought important for maintenance of instructions and strategies in schizophrenia. The observed alteration in the balance between DAN/FPN and DMN in patients may reflect a general mechanism underlying multiple forms of cognitive impairment in schizophrenia, including global processing deficits such as cognitive inefficiency and impaired context processing.
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Affiliation(s)
- Todd S Woodward
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada; BC Mental Health and Addictions Research Institute, Provincial Health Services Authority, Vancouver, BC, Canada.
| | - KaWai Leong
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Nicole Sanford
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada; BC Mental Health and Addictions Research Institute, Provincial Health Services Authority, Vancouver, BC, Canada
| | - Christine M Tipper
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada; BC Mental Health and Addictions Research Institute, Provincial Health Services Authority, Vancouver, BC, Canada
| | - Katie M Lavigne
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada; BC Mental Health and Addictions Research Institute, Provincial Health Services Authority, Vancouver, BC, Canada
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Sanford N, Veckenstedt R, Moritz S, Balzan RP, Woodward TS. Impaired integration of disambiguating evidence in delusional schizophrenia patients. Psychol Med 2014; 44:2729-2738. [PMID: 25065271 DOI: 10.1017/s0033291714000397] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND It has been previously demonstrated that a cognitive bias against disconfirmatory evidence (BADE) is associated with delusions. However, small samples of delusional patients, reliance on difference scores and choice of comparison groups may have hampered the reliability of these results. In the present study we aimed to improve on this methodology with a recent version of the BADE task, and compare larger groups of schizophrenia patients with/without delusions to obsessive-compulsive disorder (OCD) patients, a population with persistent and possibly bizarre beliefs without psychosis. METHOD A component analysis was used to identify cognitive operations underlying the BADE task, and how they differ across four groups of participants: (1) high-delusional schizophrenia, (2) low-delusional schizophrenia, (3) OCD patients and (4) non-psychiatric controls. RESULTS As in past studies, two components emerged and were labelled 'evidence integration' (the degree to which disambiguating information has been integrated) and 'conservatism' (reduced willingness to provide high plausibility ratings when justified), and only evidence integration differed between severely delusional patients and the other groups, reflecting delusional subjects giving higher ratings for disconfirmed interpretations and lower ratings for confirmed interpretations. CONCLUSIONS These data support the finding that a reduced willingness to adjust beliefs when confronted with disconfirming evidence may be a cognitive underpinning of delusions specifically, rather than obsessive beliefs or other aspects of psychosis such as hallucinations, and illustrates a cognitive process that may underlie maintenance of delusions in the face of counter-evidence. This supports the possibility of the BADE operation being a useful target in cognitive-based therapies for delusions.
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Affiliation(s)
- N Sanford
- Department of Psychiatry,University of British Columbia,Vancouver, BC,Canada
| | - R Veckenstedt
- Department of Psychiatry and Psychotherapy, Clinical Neuropsychology,University Medical Centre Hamburg-Eppendorf,Germany
| | - S Moritz
- Department of Psychiatry and Psychotherapy, Clinical Neuropsychology,University Medical Centre Hamburg-Eppendorf,Germany
| | - R P Balzan
- School of Psychology,Flinders University,Australia
| | - T S Woodward
- Department of Psychiatry,University of British Columbia,Vancouver, BC,Canada
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Rinaldi R, Trappeniers J, Lefebvre L. Shall we use non-verbal fluency in schizophrenia? A pilot study. Psychiatry Res 2014; 216:314-9. [PMID: 24636246 DOI: 10.1016/j.psychres.2014.01.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 11/29/2013] [Accepted: 01/18/2014] [Indexed: 11/18/2022]
Abstract
Over the last few years, numerous studies have attempted to explain fluency impairments in people with schizophrenia, leading to heterogeneous results. This could notably be due to the fact that fluency is often used in its verbal form where semantic dimensions are implied. In order to gain an in-depth understanding of fluency deficits, a non-verbal fluency task - the Five-Point Test (5PT) - was proposed to 24 patients with schizophrenia and to 24 healthy subjects categorized in terms of age, gender and schooling. The 5PT involves producing as many abstract figures as possible within 1min by connecting points with straight lines. All subjects also completed the Frontal Assessment Battery (FAB) while those with schizophrenia were further assessed using the Positive and Negative Syndrome Scale (PANSS). Results show that the 5PT evaluation differentiates patients from healthy subjects with regard to the number of figures produced. Patients׳ results also suggest that the number of figures produced is linked to the "overall executive functioning" and to some inhibition components. Although this study is a first step in the non-verbal efficiency research field, we believe that experimental psychopathology could benefit from the investigations on non-verbal fluency.
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Affiliation(s)
- Romina Rinaldi
- Cognitive Psychology and Neuropsychology Department, UMONS Research Institute for Health Sciences and Technology, University of Mons, Belgium.
| | - Julie Trappeniers
- Cognitive Psychology and Neuropsychology Department, UMONS Research Institute for Health Sciences and Technology, University of Mons, Belgium
| | - Laurent Lefebvre
- Cognitive Psychology and Neuropsychology Department, UMONS Research Institute for Health Sciences and Technology, University of Mons, Belgium
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Neill E, Rossell SL. Executive functioning in schizophrenia: the result of impairments in lower order cognitive skills? Schizophr Res 2013; 150:76-80. [PMID: 23973320 DOI: 10.1016/j.schres.2013.07.034] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 06/28/2013] [Accepted: 07/14/2013] [Indexed: 10/26/2022]
Abstract
Executive functioning (EF) impairments are common in schizophrenia. There are two propositions regarding the causes of these impairments: (1) executive impairments are the result of the compounding effects of deficits in lower order cognitive skills (e.g. processing speed, attention) or (2) EF impairments exist in their own right regardless of lower order skills. It is difficult to examine the separable effects of lower order cognitive skills on EF given the overlap required to complete most neuropsychological measures. One battery designed to parcel out the contributions of lower order skills from EF is the Delis-Kaplan Executive Function System (D-KEFS). Inhibition and switching specifically were examined using the D-KEFS versions of the Stroop and Trails task. No group differences in task performance after controlling for lower level skills would provide evidence for a generalised cognitive deficit. Group differences remaining after controlling for these influences would suggest a disproportionate deficit. Results supported both propositions. On both tasks, group differences reflecting slowed reaction time in the schizophrenia group disappeared when lower order skills were controlled for. Differences between groups performance in errors were only evident on the most complex versions of each task with more errors made by the schizophrenia group. These results suggest that (1) both RT and error data are needed to provide a full picture of performance and (2) the relationship between lower order and EF is too complex to provide support for one or the other proposal.
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Affiliation(s)
- Erica Neill
- Monash Alfred Psychiatry Research Centre (MAPrc), Central Clinical School, Faculty of Medicine, Nursing and Health Science, Monash University, Level 4, 607 St Kilda Rd, Melbourne, VIC 3004 Australia.
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Lesh TA, Westphal AJ, Niendam TA, Yoon JH, Minzenberg MJ, Ragland JD, Solomon M, Carter CS. Proactive and reactive cognitive control and dorsolateral prefrontal cortex dysfunction in first episode schizophrenia. NEUROIMAGE-CLINICAL 2013; 2:590-9. [PMID: 24179809 PMCID: PMC3777717 DOI: 10.1016/j.nicl.2013.04.010] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 03/26/2013] [Accepted: 04/16/2013] [Indexed: 01/11/2023]
Abstract
Cognitive control deficits have been consistently documented in patients with schizophrenia. Recent work in cognitive neuroscience has hypothesized a distinction between two theoretically separable modes of cognitive control—reactive and proactive. However, it remains unclear the extent to which these processes are uniquely associated with dysfunctional neural recruitment in individuals with schizophrenia. This functional magnetic resonance imaging (fMRI) study utilized the color word Stroop task and AX Continuous Performance Task (AX-CPT) to tap reactive and proactive control processes, respectively, in a sample of 54 healthy controls and 43 patients with first episode schizophrenia. Healthy controls demonstrated robust dorsolateral prefrontal, anterior cingulate, and parietal cortex activity on both tasks. In contrast, patients with schizophrenia did not show any significant activation during proactive control, while showing activation similar to control subjects during reactive control. Critically, an interaction analysis showed that the degree to which prefrontal activity was reduced in patients versus controls depended on the type of control process engaged. Controls showed increased dorsolateral prefrontal cortex (DLPFC) and parietal activity in the proactive compared to the reactive control task, whereas patients with schizophrenia did not demonstrate this increase. Additionally, patients' DLPFC activity and performance during proactive control was associated with disorganization symptoms, while no reactive control measures showed this association. Proactive control processes and concomitant dysfunctional recruitment of DLPFC represent robust features of schizophrenia that are also directly associated with symptoms of disorganization. Cognitive control and fronto-parietal recruitment are disrupted in schizophrenia. Schizophrenia patients show hypoactivation during proactive not reactive control. DLPFC activity was associated with disorganization only in proactive control. Proactive control deficits may reflect a more robust marker of disease pathology.
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Affiliation(s)
- Tyler A. Lesh
- Department of Psychiatry, University of California, Davis, USA
| | | | - Tara A. Niendam
- Department of Psychiatry, University of California, Davis, USA
| | - Jong H. Yoon
- Department of Psychiatry, University of California, Davis, USA
| | | | | | - Marjorie Solomon
- Department of Psychiatry, University of California, Davis, USA
- MIND Institute, University of California, Davis, USA
| | - Cameron S. Carter
- Department of Psychiatry, University of California, Davis, USA
- Department of Psychology, University of California, Davis, USA
- Corresponding author at: UC Davis Imaging Research Center, 4701 X Street, Suite E, Sacramento, CA 95817, USA.
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Rinaldi R, Lefebvre L, Trappeniers J. Language, executive functioning and symptomatology—Is fluency a transversal tool in schizophrenia? ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ojpsych.2013.34038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Bejaoui M, Pedinielli JL. Flexibilité cognitive, attention sélective et fluidité verbale sémantique dans trois dimensions de schizophrénie : psychotique, négative et de désorganisation. PRAT PSYCHOL 2010. [DOI: 10.1016/j.prps.2009.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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14
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Ventura J, Thames AD, Wood RC, Guzik LH, Hellemann GS. Disorganization and reality distortion in schizophrenia: a meta-analysis of the relationship between positive symptoms and neurocognitive deficits. Schizophr Res 2010; 121:1-14. [PMID: 20579855 PMCID: PMC3160271 DOI: 10.1016/j.schres.2010.05.033] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 05/23/2010] [Accepted: 05/26/2010] [Indexed: 11/22/2022]
Abstract
BACKGROUND Factor analytic studies have shown that in schizophrenia patients, disorganization (e.g., conceptual disorganization and bizarre behavior) is a separate dimension from other types of positive symptoms such as reality distortion (delusions and hallucinations). Although some studies have found that disorganization is more strongly linked to neurocognitive deficits and poor functional outcomes than reality distortion, the findings are not always consistent. METHODS A meta-analysis of 104 studies (combined n=8015) was conducted to determine the magnitude of the relationship between neurocognition and disorganization as compared to reality distortion. Additional analyses were conducted to determine whether the strength of these relationships differed depending on the neurocognitive domain under investigation. RESULTS The relationship between reality distortion and neurocognition was weak (r=-.04; p=.03) as compared to the moderate association between disorganization and neurocognition (r=-.23; p<.01). In each of the six neurocognitive domains that were examined, disorganization was more strongly related to neurocognition (r's range from -.20 to -.26) than to reality distortion (r's range from .01 to -.12). CONCLUSIONS The effect size of the relationship between neurocognition and disorganization was significantly larger than the effect size of the relationship between neurocognition and reality distortion. These results hold across several neurocognitive domains. These findings support a dimensional view of positive symptoms distinguishing disorganization from reality distortion.
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Affiliation(s)
- Joseph Ventura
- UCLA Department of Psychiatry, 300 Medical Plaza, Room 2243, Los Angeles CA 90095-6968, United States.
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15
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Speechley WJ, Whitman JC, Woodward TS. The contribution of hypersalience to the "jumping to conclusions" bias associated with delusions in schizophrenia. J Psychiatry Neurosci 2010; 35:7-17. [PMID: 20040242 PMCID: PMC2799500 DOI: 10.1503/jpn.090025] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Previous schizophrenia research involving the "beads task" has suggested an association between delusions and 2 reasoning biases: (1) "jumping to conclusions" (JTC), whereby early, resolute decisions are formed on the basis of little evidence and (2) over-adjustment of probability estimates following a single instance of disconfirmatory evidence. In the current study, we used a novel JTC-style paradigm to provide new information about a cognitive operation common to these 2 reasoning biases. METHODS Using a task that required participants to rate the likelihood that a fisherman was catching a series of black or white fish from Lake A and not Lake B, and vice versa, we compared the responses of 4 groups (healthy, bipolar, nondelusional schizophrenia and delusional schizophrenia) when we manipulated 2 elements of the Bayesian formula: incoming data and prior odds. RESULTS Regardless of our manipulations of the Bayesian formula, the delusional schizophrenia group gave significantly higher likelihood ratings for the lake that best matched the colour of the presented fish, but the ratings for the nonmatching lake did not differ from the other groups. LIMITATIONS The limitations of this study include a small sample size for the group of severely delusional patients and a preponderance of men in the schizophrenia sample. CONCLUSION Delusions in schizophrenia are associated with hypersalience of evidence-hypothesis matches but normal salience of nonmatches. When the colour of the incoming data is uniform (fish of only one colour), this manifests as JTC early in a series, and when the colour of incoming data varies (both black and white fish), this manifests as an overadjustment midseries. This account can provide a unifying explanation for delusion-associated performance patterns previously observed in the beads task in schizophrenia.
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Affiliation(s)
- William J Speechley
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
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16
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Woodward TS, Mizrahi R, Menon M, Christensen BK. Correspondences between theory of mind, jumping to conclusions, neuropsychological measures and the symptoms of schizophrenia. Psychiatry Res 2009; 170:119-23. [PMID: 19906438 DOI: 10.1016/j.psychres.2008.10.018] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Revised: 09/26/2008] [Accepted: 10/23/2008] [Indexed: 11/29/2022]
Abstract
Tasks measuring reasoning biases and social cognition were originally applied to the study of schizophrenia in order to shed light on the cognitive underpinnings of positive symptoms. However, the empirical evidence for overlap between these tasks, and their association with positive symptoms, remains preliminary. In the current study we explore these associations using multivariate methodology, with primary interest in two commonly studied paradigms: jumping to conclusions (JTC) and theory of mind (ToM). We also included measures of memory, executive function and fluency performance, in order to relate the cognitive constructs to more traditional neuropsychological constructs. Forty-six schizophrenia inpatients were administered JTC, ToM, verbal fluency, executive functioning, and verbal memory tasks. A principal component analysis resulted in three components interpreted as Memory, Elaboration and Flexibility. ToM loaded with verbal fluency on the Elaboration component, whereas JTC loaded with executive functioning on the Flexibility component. The negative susbscale of the Positive and Negative Syndrome Scale (PANSS) correlated with the Elaboration component, but no other component-subscale correlations reached significance. Implications of these results are that impairments in elaboration may underlie the commonly observed correlation between ToM and negative symptoms, but argue against a common neurocognitive system for JTC, ToM and positive symptoms.
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Affiliation(s)
- Todd S Woodward
- Department of Psychiatry, University of British Columbia, Vancouver, Canada.
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Buchy L, Torres IJ, Liddle PF, Woodward TS. Symptomatic determinants of insight in schizophrenia spectrum disorders. Compr Psychiatry 2009; 50:578-83. [PMID: 19840598 DOI: 10.1016/j.comppsych.2009.01.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Revised: 01/10/2009] [Accepted: 01/12/2009] [Indexed: 11/25/2022] Open
Abstract
Impaired insight in schizophrenia spectrum disorders has been linked to several psychopathologic features including positive symptoms, although not all dimensions of psychopathology have been studied and confounds from other symptoms have not been ruled out. In addition, the nature of the association between insight and specific positive symptoms, in particular delusions, remains unclear. The present investigation examined whether, in patients with schizophrenia spectrum disorders insight is associated with specific symptom dimensions including delusional severity. The factor structure was determined from scores of 151 patients rated on the Signs and Symptoms of Psychotic Illness scale. Associations of the Signs and Symptoms of Psychotic Illness insight item with the resulting components and delusions were assessed using regression-based methodology. Principal component analysis revealed 4 orthogonal symptom clusters. Correlational analyses demonstrated that only depression/anxiety and psychomotor excitation were significantly related to insight. Hierarchical regression indicated that delusions explained unique variance in insight over and above depression/anxiety and psychomotor excitation. These results suggest that depression/anxiety is associated with better insight and that psychomotor excitation and delusions are associated with poorer insight.
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Affiliation(s)
- Lisa Buchy
- Department of Psychology, Simon Fraser University, Burnaby, British Columbia, Canada
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18
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Vogel AP, Chenery HJ, Dart CM, Doan B, Tan M, Copland DA. Verbal fluency, semantics, context and symptom complexes in schizophrenia. JOURNAL OF PSYCHOLINGUISTIC RESEARCH 2009; 38:459-473. [PMID: 19259818 DOI: 10.1007/s10936-009-9100-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Accepted: 02/12/2009] [Indexed: 05/27/2023]
Abstract
Lexical-semantic access and retrieval was examined in 15 adults diagnosed with schizophrenia and matched controls. This study extends the literature through the inclusion of multiple examinations of lexical-semantic production within the same patient group and through correlating performance on these tasks with various positive and negative clinical symptoms. On tasks of verbal fluency, meaning generation, sentence production using contextual information and confrontation naming, participants with schizophrenia made significantly more semantic errors on naming tasks; produced fewer meanings for homophones; produced fewer items on semantic, phonological, cued and switching fluency tasks; and produced more errors on sentence production tasks when compared to healthy controls. Significant correlations were also observed between ratings of psychomotor poverty and measures of semantic production and mental inflexibility. This study has provided additional evidence for deficits in lexical-semantic retrieval which are not due to underlying semantic store degradation, do not involve phonological based retrieval, and at the level of sentence generation appear to vary as a function of the contextual constraints provided.
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Affiliation(s)
- Adam P Vogel
- Centre for Neuroscience, University of Melbourne, 7/21 Victoria Street, Melbourne, VIC, 3000, Australia.
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Thornton AE, Kristinsson H, DeFreitas VG, Thornton WL. The ecological validity of everyday cognition in hospitalized patients with serious mental illness. J Clin Exp Neuropsychol 2009; 32:299-308. [DOI: 10.1080/13803390903002209] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Allen E. Thornton
- a Department of Psychology , Simon Fraser University , Burnaby, British Columbia, Canada
- b British Columbia Mental Health and Addiction Services Research Institute , Vancouver, British Columbia, Canada
| | - Hayley Kristinsson
- a Department of Psychology , Simon Fraser University , Burnaby, British Columbia, Canada
| | - Vanessa G. DeFreitas
- a Department of Psychology , Simon Fraser University , Burnaby, British Columbia, Canada
| | - Wendy Loken Thornton
- a Department of Psychology , Simon Fraser University , Burnaby, British Columbia, Canada
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Dibben CRM, Rice C, Laws K, McKenna PJ. Is executive impairment associated with schizophrenic syndromes? A meta-analysis. Psychol Med 2009; 39:381-392. [PMID: 18588741 DOI: 10.1017/s0033291708003887] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND A key neuropsychological proposal in schizophrenia is that negative and disorganization symptoms are associated with different patterns of impairment on executive tasks. METHOD Studies reporting correlations between positive, negative or disorganization symptoms and any type of executive test were meta-analysed. The influence of moderating factors was also examined, including age, treatment and stage of illness and whether symptoms were relapsing or persistent. The magnitudes of the correlations were compared with those for general intellectual impairment. RESULTS Pooled correlations between executive impairment and both negative symptoms and disorganization were significant in the small-to-moderate range. That for positive symptoms ('reality distortion'), however, was close to zero. The pattern of correlations among different executive tests differed significantly for negative symptoms and disorganization. Patients with stable clinical pictures showed significantly higher correlations with executive impairment than those with relapsing and remitting illnesses. Both negative symptoms and disorganization also correlated significantly with general intellectual function as indexed by current IQ. CONCLUSIONS Meta-analysis supports the view that negative symptoms and disorganization are associated with partially dissociable patterns of executive impairment. However, co-existent general intellectual impairment has been an important confounding factor in the studies to date.
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Stroop interference effect in schizophrenic patients: An electrophysiological approach. Int J Psychophysiol 2009; 71:248-57. [DOI: 10.1016/j.ijpsycho.2008.10.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 09/25/2008] [Accepted: 10/16/2008] [Indexed: 11/20/2022]
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Kebir O, Dellagi L, Ben Azouz O, Rabeh Y, Sidhom O, Tabbane K. Déficits des fonctions exécutives dans la schizophrénie selon les dimensions positive, négative et de désorganisation. ANNALES MEDICO-PSYCHOLOGIQUES 2008. [DOI: 10.1016/j.amp.2006.04.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Stip E, Corbière M, Boulay LJ, Lesage A, Lecomte T, Leclerc C, Ricard N, Cyr M, Guillem F. Intrusion errors in explicit memory: their differential relationship with clinical and social outcome in chronic schizophrenia. Cogn Neuropsychiatry 2007; 12:112-27. [PMID: 17453894 DOI: 10.1080/13546800600809401] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Memory deficits might account for clinical and adaptive differences between groups of patients with chronic schizophrenia. We investigated the qualitative factors of memory that influence clinical and social status. METHODS Psychosocial functioning, clinical symptoms, and memory function were assessed in 99 patients at four time points over a 16-month period using recall scores for semantically related words, unrelated words, paired associated learning, and word span. An initial cluster analysis using symptom assessment data from all four time points divided the sample into three groups: patients with low symptoms ratings that remained stable throughout the study period (low symptom-stable group - LSSG; N=51); patients with initially high symptoms ratings that subsequently improved (high symptom-improved group - HSIG; N=32); and patients with initially high symptoms ratings that deteriorated during the follow-up (high symptom-deteriorated group - HSDG; N=16). RESULTS Memory was better preserved in LSSG compared to HSIG and HSDG patients. Recall performance was generally better for semantically related words than for unrelated words but the difference between LSSG and the two other groups was more constant over time for semantically related words. Extra-list errors variable was positively correlated with three PANSS measures (r=.25-.47). Also, the extra-list errors scores were correlated with the Magical Ideation Scale (r=.34-.39). Memory scores (global explicit, unrelated, related) were significantly and positively correlated with independent living skills (r=.26-.55) and the extra-list errors were negatively correlated with both social support and independent living skills (r=-.29 and r=-.46, respectively). All groups showed a reduction in extraneous false recognition errors/intrusions (FRIs) over time with the HSIG showing the greater change. HSIG and HSDG patients committed slightly more FRIs in recall tasks (extraneous information) than LSSG patients. CONCLUSION Memory performance is better in patients presenting with less severe symptomatology. The extent to which FRIs reduce over time in patients with schizophrenia is a novel finding.
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Affiliation(s)
- Emmanuel Stip
- Department of Psychiatry, Centre de Recherche Fernand-Seguin, Hôpital Louis-H. Lafontaine, Université de Montréal, Quebec, Canada.
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Woodward TS, Moritz S, Arnold MM, Cuttler C, Whitman JC, Lindsay DS. Increased hindsight bias in schizophrenia. Neuropsychology 2006; 20:461-7. [PMID: 16846264 DOI: 10.1037/0894-4105.20.4.461] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
An underlying theme common to prominent theoretical accounts of cognition in schizophrenia is that information processing is disproportionately influenced by recently/currently encountered information relative to the influence of previously learned information. In this study, the authors tested this account by using the hindsight bias or knew-it-all-along (KIA) paradigm, which demonstrates that newly acquired knowledge influences recall of past events. In line with the account that patients with schizophrenia display a disproportionately strong influence of recently encountered information relative to the influence of previously learned information, patients displayed a KIA effect that was significantly greater than in controls. This result is discussed in the context of the cognitive underpinnings of the KIA effect and delusion formation.
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Affiliation(s)
- Todd S Woodward
- Department of Research, Riverview Hospital, 2601 Lougheed Highway, Coquitlam, British Columbia, Canada.
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Christensen KM, Mateer CA, Williams R, Woodward TS. Neuropsychological deficits, syndromes, and cognitive competency in schizophrenia. Cogn Neuropsychiatry 2005; 10:361-78. [PMID: 16571467 DOI: 10.1080/13546800444000100] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Neuropsychological functioning connects neuropathology and symptoms in schizophrenia. Previous work suggests that deficient initiation and inhibition underlie the psychomotor poverty and disorganisation syndromes, respectively. Furthermore, although the syndromes are associated with impairments in everyday functioning, cognitive competency (CC; cognitive skills for independent living) has been neglected as an outcome. This study tested a three-level model of schizophrenia pathology (Neuropsychological dysfunction --> Syndromes --> CC), using unstructured neuropsychological tasks to measure initiation and inhibition. METHODS Participants were 40 adults with schizophrenia. A verbal picture description and the Tinkertoy test yielded initiation and inhibition measures with good interrater reliability. Symptoms were rated using the SANS and SAPS, and an insight scale was administered. The Cognitive Competency Test utilised simulated situations to assess CC. RESULTS Initiation failed to predict psychomotor poverty, but affected CC directly. Only one indicator of disinhibition (intermingling of personal material into speech) predicted disorganisation, which, through mediation, led to CC deficits. Insight correlated with disorganisation and contributed to CC. Unique effects of initiation, disorganisation, and insight, combined, explained 58% of CC variance. CONCLUSIONS Partial support for the three-level model was obtained. Specific neuropsychological abilities and symptoms explain a substantial proportion of the variance in cognitive competency.
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Longevialle-Hénin R, Bourdel MC, Willard D, Lôo H, Olié JP, Poirier MF, Krebs MO, Amado I. [Visuospatial context processing in untreated schizophrenic patients and relation to disorganization syndrome]. Encephale 2005; 31:323-9. [PMID: 16142047 DOI: 10.1016/s0013-7006(05)82397-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIM Previous studies on schizophrenia have suggested that context-processing disturbances were one of the core cognitive deficits present in schizophrenia. Schizophrenic patients have a failure either of inhibition strategy and maintenance of visuospatial information (25) in condition of contextual interference. In the present study, we explored the performances of untreated schizophrenic patients with 2 tasks exploring detection and long term retention of complex visual features and field dependence-independence tasks were selected. These abilities involve temporary maintenance of visuospatial information and executive functioning of visual working memory system. Several studies have shown that cognitive deficit may depend on schizophrenic symptomatology. However results remain controversial in determining the specific influence of negative and positive symptomatologies as well as clinical disorganization. Our goal was to explore the processing of spatial context and its relation to disorganized syndrome. This study was approved by the local ethic committee. METHODOLOGY Thirty-six schizophrenic patients were included according to DSM IV criteria (19 neuroleptic naïve, 17 unmedicated patients during more than 3 months). Thirty-six healthy controls were matched to patients for age, gender and level of education. Absence of axis 1 pathology was attested for controls with SCID-NP. Current symptomatology was evaluated by the Positive and Negative Syndrome Scale (PANSS) (14). Clinical disorganisation was evaluated with the disorganisation score established upon a factorial analysis of PANSS by Lepine and Lançon. Items selected to distinguish the disorganised group were abstraction, disorganization, orientation, and attention. PROCEDURE Two tasks of embedded figures were administered individually to patients and controls. The Faverge task (Research of Figures-RF) (10) evaluates the ability to recognize the target from spatial complex geometrical figures. The Group Embedded Figure Task (GEFT - Oltman) assesses the detection and maintenance of visual target and its recognition within a complex figure. Performance between patients and controls were compared with the Student T test. The comparison of two clinical subgroups of disorganized and low disorganized patients and control group was performed with an ANOVA. Tuckey test was used for pairwise comparisons. RESULTS We defined two subgroups of patients, disorganized patients (subscore 12, n=17) and low disorganized patients (subscore<12, n=19). Theses 2 subgroups were similar for age and level of education. Concerning the two tasks, there was no significant difference between schizophrenic patients and normal controls. The comparison between subgroups of disorganized and low disorganized patients, for RF task, showed a decrease of correct answers with disorganized patients (p<0.05). For GEFT task, disorganized patients had a decrease of correct answers p<0.01) and more errors (p<0.01) and omissions (p<0.05). The low disorganized patients exhibited for the two tests comparable performance to controls. The disorganized patients had a decrease of right answers (p<0.05) and more errors (p<0.05) than controls for GEFT task and no significant difference for RF. However, with IQ (evaluated with an abstract reasoning test) introduced as covariate, only correct answers for GEFT task remain significant (p<0.05). DISCUSSION The weak performance of disorganized schizophrenic patients for two tasks RF and GEFT showed that treatment of visuospatial information was impaired in the first perceptive phase of selection and in the organization of information (RF), especially with the maintenance of visual information in memory (GEFT). By contrast, low disorganized patients demonstrated a correct analytic treatment of elementary processing and visuospatial working memory. CONCLUSION The severity of disorganization influences the visuospatial context processing and visuospatial working memory. These results show the heterogeneity of cognitive functioning regarding to schizophrenic symptomatologies. This difficulty could be related to a problem of central executive functioning in the visuospatial component of working memory, possibly mediated by the dysfunction of dorsolateral prefrontal cortex.
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Woodward TS, Whitman JC, Arbuthnott K, Kragelj TL, Lyons J, Stip E. Visual search irregularities in schizophrenia depend on display size switching. Cogn Neuropsychiatry 2005; 10:137-52. [PMID: 16571457 DOI: 10.1080/13546800344000010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
INTRODUCTION In past research it has been demonstrated that when performing a visual search task with either one or multiple (4, 7 or 10) stimuli displayed, patients with schizophrenia demonstrate slow response times (RTs) in the display size of one, target-absent (one-absent) condition. The goals of the present investigation were to replicate this effect, and to gain an understanding of the underlying cognitive operations by comparing display-size switch to display-size repeat trials. METHODS In two experiments, patients and controls performed a visual search task with either one or four stimuli displayed. In Experiment 1 (one block with mixed switch and repeat trials), RT for display-size switch trials was compared to RT from display-size repeat trials. In Experiment 2, the display-size one and display-size four conditions were run in separate, homogeneous blocks. RESULTS The results demonstrate that the one-absent slowing effect was eliminated on repeat trials, regardless of whether the switch and repeat trials were mixed or presented in separate blocks. CONCLUSIONS This set of results suggests that a combination of cueing and switching effects may underlie the one-absent slowing observed in patients, such that switching to the one-absent condition is difficult due to insufficient cueing of the relevant cognitive operations. This visual search paradigm is an excellent candidate for inclusion in the development of a neurocognitive profile specific to schizophrenia.
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Woodward TS, Thornton AE, Ruff CC, Moritz S, Liddle PF. Material-specific episodic memory associates of the psychomotor poverty syndrome in schizophrenia. Cogn Neuropsychiatry 2004; 9:213-27. [PMID: 16571582 DOI: 10.1080/13546800344000219] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Episodic memory deficits consistently correlate with the presence of negative symptoms in schizophrenia, suggesting overlap between the underlying neural systems. Functional neuroimaging and lesion studies suggest that prefrontal hypoactivity may underlie both. The purpose of the present study was to further characterise this association in terms of functional lateralisation. A more pronounced association between psychomotor poverty and verbal memory deficits would suggest more left prefrontal overlap than right, and vice-versa for a more pronounced association with nonverbal memory deficits. METHODS A total of 68 inpatients (48 males, 20 females) diagnosed with schizophrenia or schizoaffective disorder participated in this study. We evaluated the correlation between verbal and nonverbal memory performance (assessed using the RAVLT and BVMT, respectively) and psychomotor poverty (assessed using the SSPI). RESULTS A trend towards a more pronounced association for nonverbal compared to verbal material was not upheld by conservative statistical testing. CONCLUSIONS Bilateral prefrontal overlap between psychomotor poverty and episodic memory is the most conservative interpretation of these data.
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