Neural Explanation of OCD

Practice questions covering the symptoms, neural mechanisms, neurochemical factors, and supporting research for the neural explanation of Obsessive Compulsive Disorder.

What are the three symptoms of Obsessive Compulsive Disorder (OCD)?

Obsessions (disturbing recurrent thoughts), emotional symptoms (guilt and anxiety), and compulsions (repetitive behaviors to reduce guilt and anxiety).

What is the function of the orbital frontal cortex in the neural explanation of OCD?

It detects worrying stimuli and selects an appropriate action to deal with them.

How does the basal ganglia interact with the orbital frontal cortex in a healthy brain?

It monitors the outcome of actions and sends inhibitory signals back to the orbitofrontal cortex to shut down signals relating to a worrying stimulus once it has been dealt with.

According to the neural explanation, what happens to the orbitofrontal cortex in people with OCD?

It receives weaker inhibitory signals from the basal ganglia, causing it to become hyperactive.

How do serotonin levels contribute to the hyperactivity of the orbitofrontal cortex in OCD patients?

People with OCD have lower levels of serotonin, leading to less inhibition of neurons in the orbitofrontal cortex, which causes them to become hyperactive.

What did Max et al discover in their case study of a girl with OCD?

An MRI revealed that the girl, who developed OCD after brain damage, had damage to her basal ganglia, suggesting that structural damage there can cause the disorder.

What were the findings of the brain imaging review conducted by Saxena and Rausch?

They found increased brain activity in the orbitofrontal cortex of adults with OCD compared to adults without OCD.

What is a major limitation of brain imaging studies regarding the neural explanation of OCD?

Results are inconsistent and do not always replicate, such as the study by Eilworth et al which observed no difference between the basal ganglia of people with OCD and healthy controls.