An fMRI Investigation of Source Memory in Obsessive-Compulsive Disorder

Abstract

Individuals with Obsessive-Compulsive Disorder (OCD) often complain about poor memory and evidence suggests that individuals with OCD exhibit deficits on some tasks, including those that are unrelated to obsessional concerns. As individuals with OCD tend to focus on details and miss the larger context, the construct of source (contextual) memory may be particularly relevant to memory complaints in OCD. Memory for different types of information (object versus contextual information) may rely on distinct regions within the prefrontal cortex and medial temporal lobe, and may be differentially impacted by obsessive-compulsive symptoms. Using a novel task, 16 individuals with OCD and 17 age, education, and gender matched healthy control group participants studied objects in the context of four rooms. While undergoing functional Magnetic Resonance Imaging (fMRI), participants completed source and object recognition testing. While no significant differences were found between the two groups in terms of behavioral performance, individuals with OCD exhibited greater task related activation in the left medial prefrontal cortex, premotor cortex, dorsolateral prefrontal cortex, right parietal region, and posterior cingulate cortical areas relative to healthy controls during correct source verses object recognition trials. Results are discussed in terms of compensatory activation and altered activation patterns in individuals with OCD.