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Functional magnetic resonance imaging of a parametric working memory task in schizophrenia: relationship with performance and effects of antipsychotic treatment.

Ettinger U, Williams SC, Fannon D, Premkumar P, Kuipers E, Möller HJ, Kumari V - Psychopharmacology (Berl.) (2011)

Bottom Line: The neural mechanisms underlying this dysfunction remain unclear, with functional neuroimaging studies reporting increased, decreased or unchanged activation compared to controls.Performance in both groups deteriorated with increasing memory load (0-back, 1-back, 2-back), but the two groups did not significantly differ in performance overall or as a function of load.This difference increased with increasing working memory load in the prefrontal areas.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry, University of Munich, Nussbaumstr. 7, 80336, Munich, Germany. ulrich.ettinger@med.uni-muenchen.de

ABSTRACT

Rationale: Working memory dysfunction is frequently observed in schizophrenia. The neural mechanisms underlying this dysfunction remain unclear, with functional neuroimaging studies reporting increased, decreased or unchanged activation compared to controls.

Objectives: We investigated the neural correlates of spatial working memory in schizophrenia with particular consideration of effects of antipsychotic treatment and relation to performance levels in the patient group.

Method: We used functional magnetic resonance imaging and studied the blood-oxygen-level-dependent (BOLD) response of 45 schizophrenia outpatients and 19 healthy controls during a parametric spatial n-back task.

Results: Performance in both groups deteriorated with increasing memory load (0-back, 1-back, 2-back), but the two groups did not significantly differ in performance overall or as a function of load. Patients produced stronger BOLD signal in occipital and lateral prefrontal cortex during task performance than controls. This difference increased with increasing working memory load in the prefrontal areas. We also found that in patients with good task performance, the BOLD response in left prefrontal cortex showed a stronger parametric increase with working memory load than in patients with poor performance. Second-generation antipsychotics were independently associated with left prefrontal BOLD increase in response to working memory load, whereas first-generation antipsychotics were associated with BOLD decrease with increasing load in this area.

Conclusions: Together, these findings suggest that in schizophrenia patients, normal working memory task performance may be achieved through compensatory neural activity, especially in well-performing patients and in those treated with second-generation antipsychotics.

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Related in: MedlinePlus

Main effect of load on BOLD across groups. The figure depicts significant BOLD response as a function of load on the n-back working memory task across both groups (p  <  0.05, FWE corrected voxel level)
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Fig1: Main effect of load on BOLD across groups. The figure depicts significant BOLD response as a function of load on the n-back working memory task across both groups (p  <  0.05, FWE corrected voxel level)

Mentions: Both groups activated an extensive fronto-parieto-striato-thalamo-cerebellar network during performance of the n-back task. Figure 1 shows the activation of the combined group as a function of load (i.e., increase in BOLD signal with increasing working memory load); the main effect of task (across conditions of load) in the combined sample gave a very similar result.Fig. 1


Functional magnetic resonance imaging of a parametric working memory task in schizophrenia: relationship with performance and effects of antipsychotic treatment.

Ettinger U, Williams SC, Fannon D, Premkumar P, Kuipers E, Möller HJ, Kumari V - Psychopharmacology (Berl.) (2011)

Main effect of load on BOLD across groups. The figure depicts significant BOLD response as a function of load on the n-back working memory task across both groups (p  <  0.05, FWE corrected voxel level)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3111549&req=5

Fig1: Main effect of load on BOLD across groups. The figure depicts significant BOLD response as a function of load on the n-back working memory task across both groups (p  <  0.05, FWE corrected voxel level)
Mentions: Both groups activated an extensive fronto-parieto-striato-thalamo-cerebellar network during performance of the n-back task. Figure 1 shows the activation of the combined group as a function of load (i.e., increase in BOLD signal with increasing working memory load); the main effect of task (across conditions of load) in the combined sample gave a very similar result.Fig. 1

Bottom Line: The neural mechanisms underlying this dysfunction remain unclear, with functional neuroimaging studies reporting increased, decreased or unchanged activation compared to controls.Performance in both groups deteriorated with increasing memory load (0-back, 1-back, 2-back), but the two groups did not significantly differ in performance overall or as a function of load.This difference increased with increasing working memory load in the prefrontal areas.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry, University of Munich, Nussbaumstr. 7, 80336, Munich, Germany. ulrich.ettinger@med.uni-muenchen.de

ABSTRACT

Rationale: Working memory dysfunction is frequently observed in schizophrenia. The neural mechanisms underlying this dysfunction remain unclear, with functional neuroimaging studies reporting increased, decreased or unchanged activation compared to controls.

Objectives: We investigated the neural correlates of spatial working memory in schizophrenia with particular consideration of effects of antipsychotic treatment and relation to performance levels in the patient group.

Method: We used functional magnetic resonance imaging and studied the blood-oxygen-level-dependent (BOLD) response of 45 schizophrenia outpatients and 19 healthy controls during a parametric spatial n-back task.

Results: Performance in both groups deteriorated with increasing memory load (0-back, 1-back, 2-back), but the two groups did not significantly differ in performance overall or as a function of load. Patients produced stronger BOLD signal in occipital and lateral prefrontal cortex during task performance than controls. This difference increased with increasing working memory load in the prefrontal areas. We also found that in patients with good task performance, the BOLD response in left prefrontal cortex showed a stronger parametric increase with working memory load than in patients with poor performance. Second-generation antipsychotics were independently associated with left prefrontal BOLD increase in response to working memory load, whereas first-generation antipsychotics were associated with BOLD decrease with increasing load in this area.

Conclusions: Together, these findings suggest that in schizophrenia patients, normal working memory task performance may be achieved through compensatory neural activity, especially in well-performing patients and in those treated with second-generation antipsychotics.

Show MeSH
Related in: MedlinePlus