How Can the Observing Response Task Help Us Understand OCD?

What you need to know

• Obsessive-compulsive disorder (OCD) affects about 3.5% of people and is characterized by unwanted thoughts and repetitive behaviors.
• A new behavioral task called the Observing Response Task allows researchers to study compulsive checking in both humans and animals.
• This task may help identify brain circuits involved in OCD and test potential treatments.

Understanding OCD

Obsessive-compulsive disorder (OCD) is a mental health condition that affects around 3.5% of people at some point in their lives. It is characterized by two main symptoms:

1. Obsessions: Unwanted, intrusive thoughts, images, or urges that cause distress.
2. Compulsions: Repetitive behaviors or mental acts that a person feels compelled to perform, often in response to obsessions.

For example, someone might have intrusive thoughts about contamination (obsession) and feel the need to wash their hands repeatedly (compulsion). While people with OCD often recognize their thoughts and behaviors are excessive, they struggle to control them.

OCD can significantly impact a person’s daily life, relationships, and ability to work. It’s estimated to cost over £5 billion annually in the UK alone when considering healthcare and broader societal costs.

Challenges in studying OCD

Researchers face several challenges when trying to understand and develop treatments for OCD:

1. Symptom variability: OCD can manifest in many different ways, making it hard to study as a single condition.
2. Difficulty separating thoughts from behaviors: While we can observe compulsive behaviors, it’s harder to measure obsessive thoughts, especially in animal studies.
3. Complexity of the brain: OCD involves multiple brain regions and circuits, making it challenging to pinpoint exact causes.

To address these challenges, researchers use various approaches, including brain imaging studies in humans and behavioral experiments in both humans and animals. However, there’s been a need for tasks that can be used across species to better understand the underlying mechanisms of OCD.

The Observing Response Task: A new tool for studying OCD

The Observing Response Task (ORT) is a newly developed behavioral task that can be used to study compulsive checking in both humans and animals. This is particularly useful because excessive checking is one of the most common symptoms of OCD.

Here’s how the task works:

1. Participants (human or animal) are presented with two response options, only one of which is correct and will lead to a reward.
2. The correct option changes unpredictably throughout the task.
3. Participants can check which option is currently correct by pressing an “observing” button or lever.
4. Researchers measure both functional checking (when information is needed) and excessive, dysfunctional checking (when the information is already known).

The ORT has several advantages for studying OCD:

1. It can be used in both humans and animals, allowing for more direct comparisons between species.
2. It distinguishes between normal, adaptive checking and excessive, maladaptive checking.
3. It allows researchers to measure individual differences in checking behavior.
4. The task can be modified to study how uncertainty or punishment affects checking behavior.

Insights from the Observing Response Task

Early studies using the ORT have provided several interesting findings:

1. Brain regions involved in checking: Damage to certain brain areas, like the medial prefrontal cortex and nucleus accumbens, can increase checking behavior in animals. This suggests these regions play a role in controlling checking behavior.

2. Individual differences: Some individuals are more prone to excessive checking, especially under conditions of uncertainty. This mirrors the variability seen in human OCD symptoms.

3. Relationship to other behaviors: Animals that show a strong attraction to reward-related cues (called “sign-trackers”) also tend to show more dysfunctional checking on the ORT. This suggests there may be common brain mechanisms underlying different types of compulsive behaviors.

4. Effects of punishment: When incorrect responses are punished, most animals increase their functional checking. However, some animals (particularly sign-trackers) continue to show high levels of dysfunctional checking even after the punishment is removed. This persistence of checking despite negative consequences is similar to what’s seen in human OCD.

Potential applications of the Observing Response Task

The ORT opens up several new avenues for OCD research:

1. Testing new treatments: Researchers can use the task to test whether potential OCD treatments reduce excessive checking in animals before moving to human trials.

2. Understanding brain circuits: By combining the ORT with brain imaging or manipulation techniques, scientists can identify which brain circuits are involved in normal vs. excessive checking.

3. Studying individual differences: The task allows researchers to explore why some individuals are more prone to compulsive checking than others.

4. Investigating related conditions: The ORT could be used to study checking behavior in other conditions where it’s common, such as anxiety disorders.

Conclusions

• The Observing Response Task is a promising new tool for studying compulsive checking behavior in both humans and animals.
• Early studies using the ORT have provided insights into brain regions involved in checking and individual differences in compulsive behavior.
• This task may help researchers develop and test new treatments for OCD by providing a way to measure compulsive checking across species.

While the ORT is still a relatively new tool, it has the potential to significantly advance our understanding of OCD and related conditions. By allowing researchers to study compulsive checking in a controlled, measurable way across species, it may help bridge the gap between animal studies and human clinical research. This could ultimately lead to more effective treatments for people struggling with OCD and other compulsive behaviors.