Can Eye Movements Reveal Organizational Deficits in OCD?

What you need to know

• People with obsessive-compulsive disorder (OCD) often have difficulty with executive functions like planning and organization.
• This study used eye tracking to examine how people with OCD visually explore and memorize a complex figure.
• Those with OCD showed poorer organizational strategies and tended to focus on details rather than the big picture.
• Eye movement patterns during visual tasks may provide a quick way to assess executive function in OCD.

Executive function deficits in OCD

Obsessive-compulsive disorder (OCD) is characterized by intrusive thoughts (obsessions) and repetitive behaviors (compulsions). While the symptoms are the most obvious part of the disorder, research has shown that people with OCD often struggle with cognitive abilities known as executive functions. These include skills like planning, organizing information, and seeing the big picture.

Understanding these cognitive difficulties is important for developing better treatments for OCD. However, the tests typically used to measure executive function can be time-consuming and complicated to administer. This study explored whether tracking eye movements during a visual memory task could provide a simpler way to assess executive function in OCD.

The Rey-Osterrieth Complex Figure Test

The researchers used a test called the Rey-Osterrieth Complex Figure Test (RCFT). This test involves showing participants a complex geometric figure and asking them to copy it and then draw it again from memory. How a person approaches copying and remembering the figure can reveal a lot about their ability to organize visual information.

In a typical RCFT, the test-taker draws the figure while an examiner watches and takes notes on their process. For this study, the researchers added eye tracking technology to get more detailed information about how participants visually explored the figure while trying to memorize it.

How the study worked

The study included 104 people diagnosed with OCD and 114 healthy control participants without OCD. Each person was shown the Rey-Osterrieth figure on a computer screen and given 3 minutes to memorize it. During this time, their eye movements were recorded using an eye tracking device. Immediately afterwards, they were asked to draw the figure from memory.

The researchers looked at several aspects of performance:

1. How accurately participants reproduced the figure from memory
2. How well they organized the elements of the figure (assessed by expert raters)
3. Patterns in their eye movements while memorizing the figure

To analyze the eye movement data, the researchers used a measure called Kullback-Leibler divergence (KLD). This allowed them to quantify how evenly distributed a person’s gaze was across the entire figure. A lower KLD score meant the person looked more evenly across the whole figure, while a higher score meant they tended to focus on specific details.

Key findings

The study revealed several important differences between the OCD and control groups:

1. Poorer recall: People with OCD were less accurate when reproducing the figure from memory compared to the control group.

2. Weaker organizational strategies: The OCD group received lower scores for how well they organized the elements of the figure, both while initially viewing it and when reproducing it from memory.

3. Detail-focused gaze patterns: While there wasn’t a significant difference in overall KLD scores between groups, there was an interesting relationship within the OCD group. OCD participants with higher KLD scores (indicating more focus on details rather than the big picture) tended to have lower organizational scores.

These findings suggest that people with OCD may have more difficulty stepping back to see the overall structure of complex visual information. Instead, they may get caught up in examining individual details, which makes it harder to remember and reproduce the figure as a whole.

Eye movements as a potential biomarker

One of the most intriguing aspects of this study is the potential for using eye tracking as a quick and objective way to assess executive function in OCD. Traditional neuropsychological tests can be time-consuming and rely heavily on subjective scoring. In contrast, eye tracking can provide a wealth of data in just a few minutes.

The relationship between gaze patterns and organizational abilities was only seen in the OCD group, not in healthy controls. This suggests that unusual eye movements during visual tasks may be a specific marker of executive function difficulties in OCD.

Limitations and future directions

It’s important to note some limitations of this study:

• Most of the OCD participants were receiving treatment (medication and/or therapy), which could have affected their performance.
• The groups were not perfectly matched on factors like age, education, and IQ, although the researchers tried to control for these statistically.
• The eye tracking measure (KLD) is relatively new and needs more research to fully understand its significance.

Future studies could explore whether eye tracking during visual tasks could be used to:

• Predict which individuals with OCD might benefit most from cognitive remediation therapy targeting executive function
• Track improvements in executive function during treatment
• Identify subtle executive function difficulties in people at risk for developing OCD

Conclusions

• People with OCD showed poorer organizational strategies and memory for complex visual information compared to those without OCD.
• Eye movement patterns during a visual memory task were related to organizational abilities in people with OCD, but not in healthy controls.
• Eye tracking technology may offer a quick and objective way to assess certain aspects of executive function in OCD.
• More research is needed to fully understand the relationship between eye movements and cognitive function in OCD and to determine how this information might be used clinically.