Brain Reactivity and Selective Attention to Sleep-Related Words in Patients With Chronic Insomnia

Sleep-related attentional bias has been suggested to represent an important factor for the maintenance of chronic insomnia. However, little is known about potentially underlying psychological mechanisms such as threat or craving. As these are associated with distinguishable brain activation patterns, we performed a functional neuroimaging study.

Functional magnetic resonance imaging was used to investigate brain reactivity to sleep-related words in 20 patients with primary insomnia according to DSM-IV criteria and 35 good sleeper controls according to Research Diagnostic Criteria. In addition, an emotional Stroop task was performed in all participants outside the scanner to investigate sleep-related attentional bias.

Contrary to the hypotheses, patients with chronic insomnia did not differ from good sleeper controls in terms of threat- or craving-related brain reactivity to sleep-related words. In addition, the emotional Stroop task did not reveal any significant group difference in sleep-related attentional bias. Exploratory analyses did not show any significant correlations between brain reactivity/selective attention to sleep-related words and questionnaire scores/PSG parameters.

The results from the present study call into question that attentional bias to sleep-related stimuli is a core feature of chronic insomnia. Future studies may use pictorial stimuli and larger sample sizes for investigating sleep-related information processing in insomnia.