Impairment of source memory in patients with obsessive-compulsive disorder: equivalent current dipole analysis.

We examined memory performance and cortical source localization of old/new effects in a source memory task in obsessive-compulsive disorder (OCD) patients by employing an equivalent current dipole (ECD) model using EEG and a realistic head model. Event-related potentials (ERPs) were recorded while 14 OCD patients and 14 age-, sex-, handedness-, and educational level-matched healthy control subjects performed recognition tasks for spoken words (items) or for the voice of the speaker of spoken words (sources). In the item memory task, both groups showed ERP old/new effects at 300-700 ms.

Cortical network dynamics during source memory retrieval: current density imaging with individual MRI.

We investigated the neural correlates of source memory retrieval using low-resolution electromagnetic tomography (LORETA) with 64 channels EEG and individual MRI as a realistic head model. Event-related potentials (ERPs) were recorded while 13 healthy subjects performed the source memory task for the voice of the speaker in spoken words. The source correct condition of old words elicited more positive-going potentials than the correct rejection condition of new words at 400-700 ms post-stimulus and the old/new effects also appeared in the right anterior region between 1,000 and 1,200 ms.