437: Resting-state EEG correlates of attentional bias to pain-related information in chronic back pain

Topic: Clinical Science
Subtopic: Pain category (ICD-11), Chronic primary musculoskeletal pain, Electrophysiology/Clinical neurophysiology (e.g. microneurography, EEG, MEG, OPMs, TMS)

Background and Aims: Attention bias towards pain-related information is mediated by intrinsic brain states which are altered in people with chronic pain.(1-3) While task-based studies demonstrate altered neural responses to pain-related stimuli (4-6), it remains unclear whether attentional bias is linked to intrinsic brain states. This study examined whether resting-state electroencephalography (EEG) features are associated with attentional bias to pain-related sensory interference, as measured by a Stroop interference task.

Methods: Resting-state EEG (~10mins) was recorded in individuals with chronic low back pain (CLBP; n=120) using 64-electrodes. Attentional bias was assessed using a modified emotional Stroop task (7,8) , and the primary outcome was the mean reaction time (RT) to sensory-interference (pain-related) trials. EEG data were pre-processed using the DISCOVER-EEG pipeline (9) (resampled to 250Hz, band-pass filtered 0.05–44 Hz, re-referenced, and artefact-corrected). Lagged-phase synchronization (eLORETA) between predefined regions of interest was used to estimate functional connectivity, a key EEG outcome, between pre-defined regions of interest (7, 10-12): bilateral somatosensory cortex (SSC), insula, and pregenual and dorsal anterior cingulate cortex (pgACC, dACC), across slow frequency bands (slow-1=0.08–0.19 Hz; slow-2=0.2–0.55 Hz; slow-3=0.6–1.5 Hz). Multiple linear regression was used to examine associations between EEG functional connectivity and RT to pain-related, sensory-interference information. RT to sensory control trials was included as a covariate to isolate pain-specific effects.

Results: EEG connectivity features were significantly associated with RT to pain-related information (R²=0.92). Increased slow-2 connectivity between left SSC and pgACC (β=0.131, p<0.001) and between right SSC and right insula (β=0.089, p=0.019) was associated with higher RT. In contrast, increased slow-1 and slow-2 connectivity between left insula and pgACC (β =−0.213, p<0.001) was associated with reduced RT. Frequency-specific effects were observed, with slow-3 connectivity between left insula and pgACC (β=0.085, p=0.016) associated with higher RT. Additionally, slow-1 connectivity between right SSC and right insula (β=−0.070, p=0.039) and between left insula and pgACC (β=−0.074, p=0.014) was associated with reduced RT.

Conclusions: Resting-state EEG functional connectivity was associated with attentional bias to pain-related information in CLBP, independent of general processing speed. Increased somatosensory–affective coupling was linked to greater pain-related sensory interference, whereas stronger insula–pgACC and slow-timescale connectivity was associated with reduced interference, suggesting distinct roles of salience and regulatory network dynamics. These findings suggest that attentional bias to pain is embedded in intrinsic brain organization and highlight resting-state EEG as a potential marker of cognitive-affective vulnerability in chronic pain.

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Presenting Author: Divya Adhia
Submitting Author: Divya Adhia

Senior Author: Divya Bharatkumar Adhia

IASP 2026 Global Year theme of Neuropathic Pain: No

• Simran Brar: MSc - University of Otago
• Ramakrishnan Mani: PhD - University of Otago
• Dirk De Ridder: PhD - University of Otago
• Divya Bharatkumar Adhia: PhD - University of Otago