Abnormalities of P300 cortical current density in unmedicated depressed patients revealed by LORETA analysis of event-related potentials
Article first published online: 17 DEC 2003
Psychiatry and Clinical Neurosciences
Volume 58, Issue 1, pages 68–75, February 2004
How to Cite
KAWASAKI, T., TANAKA, S., WANG, J., HOKAMA, H. and HIRAMATSU, K. (2004), Abnormalities of P300 cortical current density in unmedicated depressed patients revealed by LORETA analysis of event-related potentials. Psychiatry and Clinical Neurosciences, 58: 68–75. doi: 10.1111/j.1440-1819.2004.01195.x
- Issue published online: 17 DEC 2003
- Article first published online: 17 DEC 2003
- Received 6 May 2003; revised 7 July 2003; accepted 13 July 2003.
- cortical current density;
- event-related potential;
- low-resolution electromagnetic tomography (LORETA);
Abstract The purpose of the present study was to investigate the neural substrates underlying event-related potential (ERP) abnormalities, with respect to the generators of the ERP components in depressed patients. Using an oddball paradigm, ERP from auditory stimuli were recorded from 22 unmedicated patients with current depressive episodes and compared with those from 22 age- and gender-matched normal controls. Cortical current densities of the N100 and P300 components were analyzed using low-resolution electromagnetic tomography (LORETA). Group differences in cortical current density were mapped on a 3-D cortex model. The results revealed that N100 cortical current densities did not differ between the two groups, while P300 cortical current densities were significantly lower in depressed patients over the bilateral temporal lobes, the left frontal region, and the right temporal–parietal area. Furthermore, the cortical area in which the group difference in P300 current density had been identified was remarkably larger over the right than the left hemisphere, thus supporting the hypothesis of right hemisphere dysfunction in depression.