Self-evaluation in schizophrenia: an fMRI study with implications for the understanding of insight Full Text
BMC Psychiatry, 08/16/2012
Bedford N et al. – The authors have demonstrated that the central midline structures (CMS), identified as a key system underpinning self–evaluation, is dysfunctional in patients with schizophrenia, particularly dorso–medial PFC. This may have implications for lack of insight in schizophrenia. Hypofunction within the dorsomedial prefrontal region seems to be particularly important although other posterior and lateral cortical regions play a part and may modulate self–evaluative responses depending on the type of trait under consideration.Methods
- Eleven schizophrenia patients and 8 healthy controls, matched for age were studied.
- Insight was assessed using the Schedule for the Assessment of Insight-expanded version (SAI-E).
- FMRI data were obtained with a 1.5 Tesla GE system and interactions between participant group, self versus other, significant at the cluster level, were recorded.
- Significant hypoactivation in the medial superior frontal gyrus (dorsomedial prefrontal cortex) was observed in patients vs. controls during self-evaluation of all traits combined.
- A second cluster of hypoactivation in the posterior cingulate was also detected.
- When the response to individual traits was explored, underactivation in other frontal regions plus right inferior parietal lobule emerged and this tended to correlate, albeit weakly with lower insight scores.
- Further, there were areas of hyperactivation relative to controls in anterior cingulate, frontal and parietal regions (especially precuneus) which showed moderate inverse correlations with insight scores.