Action-monitoring dysfunction in obsessive-compulsive disorder

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychiatry

Background:

• Obsessive-compulsive disorder (OCD) is linked to hyperactivity in the frontal-striatal-thalamic-frontal circuit.
• The precise function of this circuit's exaggerated activity in OCD remains debated.

Purpose of the Study:

• To investigate the functional role of hyperactive frontal-striatal-thalamic-frontal circuits in OCD.
• To explore whether enhanced neural activity in OCD patients reflects aberrant event monitoring and error signaling.

Main Methods:

• Electrophysiological recordings using a speeded reaction time task.
• Comparison of event-related brain potentials between 9 individuals with OCD and 9 matched controls.
• Dipole modeling to localize the neural source of observed brain activity.

Main Results:

• Individuals with OCD exhibited an enhanced error-related negativity (ERN), a marker of action monitoring.
• The degree of ERN enhancement in OCD patients positively correlated with their symptom severity.
• Source localization indicated that the enhanced ERN originated in medial frontal regions, potentially the anterior cingulate cortex.

Conclusions:

• The findings suggest that a hyperactive frontal-striatal-thalamic-frontal circuit in OCD may involve an oversensitive error-monitoring system.
• This enhanced error signaling could contribute to the persistent, intrusive thoughts and compulsive behaviors characteristic of OCD.
• The anterior cingulate cortex is implicated as a potential neural substrate for this aberrant monitoring process in OCD.