How Do Brain Responses to Errors Differ in OCD, Tourette's, ADHD, and Autism?

What you need to know

• The study compared brain responses to errors across OCD, Tourette’s syndrome, ADHD, and autism using meta-analysis.

• OCD and Tourette’s syndrome showed increased brain activity when detecting errors, while ADHD and autism showed decreased activity.

• OCD had more widespread increases in error-related brain activity compared to the other conditions.

• The findings suggest some shared brain mechanisms between OCD and Tourette’s, and between ADHD and autism.

• Understanding these similarities and differences may help improve diagnosis and treatment of these conditions.

How our brains detect and process errors

Our brains have systems that constantly monitor our thoughts and actions to make sure they align with our goals. When we make a mistake, specialized brain areas quickly detect the error and trigger responses to help us adapt our behavior.

Researchers can measure this error detection process using a technique called electroencephalography (EEG). EEG records the electrical activity of large groups of brain cells from sensors placed on the scalp. When the brain detects an error, it produces specific patterns in the EEG signal within milliseconds.

One key EEG marker of error detection is called the error-related negativity (ERN). The ERN appears as a negative deflection in brain activity about 50-100 milliseconds after an error is made. It is thought to reflect activity in a brain region called the anterior cingulate cortex as it detects a mismatch between the expected and actual outcome of an action.

Another important EEG component is the error positivity (Pe), which occurs around 200-500 milliseconds after an error. The Pe is believed to represent more conscious processing of the error, potentially reflecting activity in the insula region of the brain.

Researchers also examine brain responses to external feedback about errors, rather than just internal error detection. The feedback-related negativity (FRN) occurs when we receive negative feedback about our performance from the environment.

Comparing error processing across conditions

Many studies have examined these error-related brain responses in people with various neurodevelopmental conditions, including obsessive-compulsive disorder (OCD), Tourette’s syndrome, attention-deficit/hyperactivity disorder (ADHD), and autism. However, the findings have been mixed across individual studies.

This meta-analysis aimed to synthesize all the existing research to get a clearer picture of how error processing may differ in these conditions. The researchers analyzed data from 97 studies including nearly 6,000 participants.

Increased error signals in OCD and Tourette’s syndrome

The meta-analysis found that people with OCD showed significantly increased amplitude of the ERN compared to control participants. This aligns with the idea that people with OCD may have an overactive error detection system, leading to excessive doubts and repetitive checking behaviors.

Interestingly, the study also found increased amplitude of the Pe and FRN components in OCD. This suggests people with OCD may have more widespread increases in error-related brain activity, affecting multiple stages of error processing.

Tourette’s syndrome was associated with increased ERN amplitude as well, though this was based on fewer studies than for OCD. The similarities in ERN increases between OCD and Tourette’s syndrome hint at some shared brain mechanisms, which makes sense given that these conditions often co-occur.

Decreased error signals in ADHD and autism

In contrast to OCD and Tourette’s syndrome, both ADHD and autism were associated with significantly decreased ERN amplitude. ADHD also showed reduced Pe amplitude.

These findings align with the idea that ADHD involves difficulties with performance monitoring and self-regulation. The decreased error signals may make it harder for people with ADHD to detect when they’ve made a mistake and adapt their behavior accordingly.

For autism, the reductions were specific to the ERN, with no differences found in the Pe component. This suggests people with autism may have particular difficulty with the initial, automatic detection of errors, rather than later, more conscious error processing.

Implications for understanding these conditions

The opposing patterns seen between OCD/Tourette’s and ADHD/autism are intriguing, especially since all of these conditions often co-occur. The findings suggest there may be some shared brain mechanisms within each of these pairs of conditions.

At the same time, OCD showed more extensive increases across multiple error-related components compared to Tourette’s syndrome. This highlights that while there are some similarities, each condition likely involves distinct patterns of altered brain function.

Understanding these shared and distinct patterns of brain activity could potentially help improve diagnosis and treatment selection. For example, treatments that target hyperactive error monitoring may be most relevant for OCD, while interventions to enhance error detection could be useful for ADHD or autism.

Conclusions

• OCD and Tourette’s syndrome are associated with increased brain responses when detecting errors, while ADHD and autism show decreased responses.

• OCD involves more widespread increases in error-related brain activity compared to the other conditions examined.

• The findings suggest some shared brain mechanisms between OCD and Tourette’s syndrome, and between ADHD and autism, which may help explain why these conditions often co-occur.

• Understanding the similarities and differences in error processing across these conditions could lead to improved diagnostic and treatment approaches targeting specific alterations in brain function.

• More research is still needed to clarify how these error-related brain responses relate to real-world symptoms and behaviors in each condition.