Abstract
An fMRI study of theory of mind in bipolar disorder
Bipolar Disorders, Vol.9(Supplement 1), p.71
International Conference on Bipolar Disorder, 7th (Pittsburgh, United States, 07-Jun-2007 - 09-Jun-2007)
2007
Abstract
Introduction: Patients with bipolar disorder report impairments of social functioning and the maintenance of relationships. This compromise is often accompanied by executive functioning deficits across mood states and periods of euthymia. An area of executive functioning that has salience in this context is that of Theory of Mind (ToM), which underpins an individual's ability to comprehend and respond suitably by way of attributing mental states to others. Some preliminary studies of ToM in bipolar disorder euthymia suggest that this ability is constrained. We sought to explore this further using a novel functionalMRI (fMRI) compatible ToM paradigm. Methods: Ten adult right-handed bipolar patients (assessed using a structured interview when euthymic) and ten healthy age and gender-matched controls underwent clinical assessment and scanning using a ToM paradigm. The latter used two animated triangles that interacted in a ToM and non-ToM manner. Subjects completed a 10-min block design experiment using alternating ToM and non-ToM conditions - presented visually within the scanner for periods of approximately 40 s. Scanning was performed using a 3T Philips Inters MRI scanner, using echo planar imaging (EIPI). fMRI volumes were acquired using a gradient EPI sequence (TE = 37 ms; TR = 3000 ms; FOV = 240; matrix = 128 x 128; flip angle = 90) and each volume contained 28-interleaved-4-mm thick slices. T1-weighted high-resolution images (matrix 256 x 256, FOV 300 mm, slice-thickness 1.3 mm) were also acquired to aid localization of the activated voxels. Concurrent eye-movements using an MRI compatible system allowed psychophysiological measures such as pupil area as well as eye gaze direction and dwell times to be acquired. Results: Findings from preliminary analyses indicate the presence of a differential pattern of prefrontal activation between the control subjects and the bipolar patients. Both groups show activation in occipital regions consistent with recognition of shape, color and movement - however, only the control group had activation in the prefrontal cortex to the ToM condition. Conclusions: A lack of activation to ToM in bipolar patients suggests dysfunction of fronto-limbic regulation that forms the substrate of social cognition. This clearly has salience both clinically and with respect to better understanding the pathophysiology of bipolar disorder.
Details
- Title
- An fMRI study of theory of mind in bipolar disorder
- Authors
- G S Malhi (Author) - University of SydneyJim Lagopoulos (Author) - University of SydneyC Cahill (Author) - University of SydneyA L Olley (Author) - University of New South WalesR C Shnier (Author) - Prince of Wales Medical Research Institute
- Publication details
- Bipolar Disorders, Vol.9(Supplement 1), p.71
- Conference details
- International Conference on Bipolar Disorder, 7th (Pittsburgh, United States, 07-Jun-2007 - 09-Jun-2007)
- Publisher
- Wiley-Blackwell Publishing Inc.
- DOI
- 10.1111/j.1399-5618.2007.00511.x
- ISSN
- 1398-5647
- Organisation Unit
- Thompson Institute; University of the Sunshine Coast, Queensland
- Language
- English
- Record Identifier
- 99450468602621
- Output Type
- Abstract
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