The Time-Course of Attentional Bias to Symptom-Related Words in Functional Gastrointestinal Disorders: An EEG Study

Abstract

Research has highlighted the role of psychological processes in functional gastrointestinal disorders (FGIDs). The presence of potentially unconscious attentional bias toward gastrointestinal symptom-related words might attest to the contribution of psychological factors in FGIDs, but few studies have addressed attentional bias in FGID-sufferers, specifically. This study aimed to use electroencephalography to examine unconscious and conscious attentional bias to symptom-related nouns in FGID-sufferers and explore how EEG indices of attention correlate with symptom severity and health anxiety. Thirty FGIDsufferers and 30 controls completed a fast-presentation task using an oddball paradigm to measure unconscious attention, a silent reading task measuring unconscious and conscious attention, and scales measuring health-related and psychosocial states. A series of symptomrelated, negative, and neutral nouns were used in both EEG tasks. One-way t-tests, comparing the signal-to-noise ratio to 1.6, were used to analyse the fast presentation task data, while mixed ANOVAs were performed on event-related potentials indicative of unconscious attention (P100 and early posterior negativity) and conscious attention (N400 and late posterior positivity) in the silent reading task. An unconscious attentional bias was not observed in either EEG task. However, vigilance for negative nouns, followed by avoidance of negative and sustained processing of symptom-related nouns was observed across groups in the silent reading task, and the strength of this vigilance-avoidance pattern correlated with health anxiety. Conversely, symptom severity did not correlate with attentional bias. A deeper understanding of the time-course of attentional bias in FGID-sufferers could inform the design and application of psychological interventions aimed at treating FGIDs.