Altered source memory retrieval is associated with pathological doubt in obsessive-compulsive disorder.

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Psychology

Background:

• Individuals with obsessive-compulsive disorder (OCD) frequently report memory doubts.
• Neuropsychological findings suggest OCD patients focus on details, potentially impairing contextual (source) memory.
• Distinct brain regions support object versus source memory, which may be differentially affected in OCD.

Purpose of the Study:

• To investigate if individuals with OCD have impaired source memory retrieval.
• To explore brain activation patterns during object and source memory tasks in OCD using fMRI.
• To correlate brain activity with pathological doubt in OCD patients.

Main Methods:

• A novel memory paradigm, the Memory for Rooms Test (MFRT), was used.
• Participants with OCD and healthy controls encoded objects within four distinct rooms.
• Functional magnetic resonance imaging (fMRI) was employed during memory retrieval tests.

Main Results:

• No significant differences in source memory accuracy were found between groups.
• Individuals with OCD showed increased posterior cingulate cortex (PCC) activation during correct source memory retrieval.
• OCD patients exhibited reduced activation in dorsolateral prefrontal (DLPFC)/premotor and parietal regions during object recognition compared to controls.

Conclusions:

• OCD is associated with abnormal recruitment of frontal-parietal and PCC regions during source versus object memory retrieval.
• Increased PCC and DLPFC activation in OCD correlated with greater pathological doubt, even with intact memory performance.
• These findings link altered brain function in specific memory processes to the subjective experience of doubt in OCD.