The authors of this paper report no biomedical financial interests or potential conflicts of interest in connection with this manuscript.
Fronto-temporal dysregulation in remitted bipolar patients: an fMRI delayed-non-match-to-sample (DNMS) study
Article first published online: 8 MAY 2009
© 2009 The Authors. Journal compilation © 2009 Blackwell Munksgaard
Volume 11, Issue 4, pages 351–360, June 2009
How to Cite
Robinson, J. L., Bearden, C. E., Monkul, E. S., Tordesillas-Gutiérrez, D., Velligan, D. I., Frangou, S. and Glahn, D. C. (2009), Fronto-temporal dysregulation in remitted bipolar patients: an fMRI delayed-non-match-to-sample (DNMS) study. Bipolar Disorders, 11: 351–360. doi: 10.1111/j.1399-5618.2009.00703.x
- Issue published online: 8 MAY 2009
- Article first published online: 8 MAY 2009
- Received 23 June 2008, revised and accepted for publication 25 November 2008
- bipolar disorder;
- medial temporal lobe;
- prefrontal cortex;
- working memory
Objectives: Bipolar disorder is associated with working memory (WM) impairments that persist during periods of symptomatic remission. However, the neural underpinnings of these deficits are not well understood.
Methods: Fifteen clinically remitted bipolar patients and 15 demographically matched healthy controls underwent functional magnetic resonance imaging while performing a novel delayed-non-match-to-sample (DNMS) task. This nonverbal DNMS task involves two conditions, one requiring the organization of existing memory traces (‘familiarity’), and one involving the formation of new memory traces (‘novelty’). These processes are thought to differentially engage the prefrontal cortex and medial temporal lobe, respectively.
Results: Although behavioral performance did not differ between groups, bipolar patients and controls exhibited significantly different patterns of neural activity during task performance. Patients showed relative hyperactivation in the right prefrontal gyrus and relative hypoactivation in visual processing regions compared to healthy subjects across both task conditions. During the novelty condition, patients showed a pattern of hypoactivation relative to controls in medial temporal regions, with relative hyperactivation in the anterior cingulate.
Conclusions: These findings suggest that disruption in fronto-temporal neural circuitry may underlie memory difficulties frequently observed in patients with bipolar disorder.