Sleep-Related Attentional Bias in Insomnia: A Drift Diffusion Model Approach

Area of Science:

• Cognitive Neuroscience
• Sleep Medicine
• Psychiatry

Background:

• Cognitive models suggest insomnia is maintained by selective attention to sleep-related stimuli.
• Reaction-time measures alone lack mechanistic specificity for attentional bias.
• Investigating attentional bias in adolescents and young adults with insomnia is crucial.

Purpose of the Study:

• To investigate sleep-related attentional bias in adolescents and young adults diagnosed with insomnia disorder.
• To utilize computational modeling (Hierarchical Drift Diffusion Modelling) for enhanced mechanistic insight.
• To examine the moderating role of anxiety symptoms on attentional bias.

Main Methods:

• A sleep-related dot-probe task using Cantonese Chinese word pairs (sleep-related and neutral).
• Hierarchical Drift Diffusion Modelling (HDDM) to estimate drift rate (v), reflecting evidence accumulation speed.
• Analysis of trial-level responses in 201 participants (aged 15-24 years) with insomnia disorder.

Main Results:

• Drift rates were significantly higher on congruent trials, indicating faster evidence accumulation for sleep-related cues.
• Higher anxiety levels correlated with faster drift rates across all trial types, suggesting generalized hyperarousal.
• No significant interaction was found between congruency and anxiety, ruling out cue-specific amplification by anxiety.

Conclusions:

• Findings provide computational evidence supporting sleep-related attentional bias in young individuals with insomnia.
• Comorbid anxiety in insomnia appears associated with generalized hyperarousal rather than amplified sleep-specific attentional bias.
• HDDM offers a more mechanistically specific approach to understanding cognitive biases in insomnia.