Attentional bias abnormalities and their association with cognitive load in obsessive-compulsive disorder

BACKGROUND: Attentional bias is a significant factor in the onset and persistence of obsessive-compulsive symptoms in individuals with obsessive-compulsive disorder (OCD). However, the determinants of attentional bias in OCD remain inadequately understood. Research has indicated that certain goal-directed cognitive control factors, particularly working memory, affect the modulation of attentional bias. This study aimed to explore the relationship between cognitive load and attentional bias in OCD. METHOD: A total of 58 OCD patients (age: 31.34 ± 7.77, male:22, female: 36) and 59 healthy controls (HC) (age: 28.81 ± 6.19, male:19, female: 40) were enrolled. This study integrated a visuospatial working memory task with a free-viewing paradigm and utilized eye-tracking. The fixation data and gaze data were collected. Repeated measures analysis of variance and temporal-course analysis were used to explore the association between attentional bias and cognitive load. RESULTS: OCD patients exhibited attentional bias to Contamination pictures, manifested as early attentional vigilance, and difficulty in attentional disengagement in the middle stage. For the direction of initial fixation (DIF), only the main effect of group was significant, F(1, 115) = 21.792, p < 0.001. Analysis of the initial fixation duration (IFD) revealed a significant effect for group, F(1, 115) = 10.352, p = 0.002, and load, F(1.831, 210.57) = 4.726, p = 0.012, as well as significant group × load interaction, F(1.831, 210.57) = 7.614, p = 0.001. The results of temporal-course analysis showed that the proportion of OCD patients' attention time on Contamination pictures was significantly higher than that of HC at 678-1751 ms under the condition of no cognitive load. Under low cognitive load conditions, the difference between the two groups began at 662 ms, while in the high cognitive load condition, significant differences appeared as early as 635 ms. CONCLUSION: The present study provides novel evidence that cognitive load modulates attentional bias towards contamination-related stimuli in OCD patients. With increasing cognitive load, OCD patients demonstrated greater difficulties disengaging attention from threatening stimuli and an earlier onset of these difficulties. These findings suggest that the sustained attentional bias toward threatening or symptom-related stimuli in OCD patients may be associated with limited cognitive control. It provides a basis for further exploration of the mechanism of attentional bias in OCD patients.