Effects of graded attentional states on acupuncture sensation: Objective evidence for Deqi from electrooculogram signals in an exploratory randomized controlled trial

Background Focused attention is traditionally considered essential for eliciting deqi during acupuncture; however, objective evidence supporting this association remains limited. Methods In this exploratory randomized controlled trial, 90 healthy participants were assigned to one of three attentional states during acupuncture: Focus Needling State (FNS), Music Needling State (MNS) and Conversation Needling State (CNS). Deqi sensations were assessed using the Chinese version of the Massachusetts General Hospital Acupuncture Sensation Scale (C-MASS). Electrooculogram (EOG) signals were continuously recorded, and the correlation dimension (D 2 ) was calculated to quantify task-induced attentional state. The primary outcome was deqi intensity, and secondary outcomes included D 2 and its association with deqi . Results The MASS index and fullness were highest in FNS and decreased with distraction ( P < 0.01). D₂ values differed significantly across groups, with the lowest values observed in FNS ( P < 0.01). Profile analysis showed a decreasing trend in primary deqi sensations across attentional states, and D₂ was negatively correlated with the MASS index ( r = −0.406) and fullness ( r = −0.300) (both P < 0.01). Receiver operating characteristic (ROC) analysis showed good discrimination of deqi response (defined as MASS index > 3), with an AUC of 0.832 (95% confidence interval 0.73 to 0.93), cutoff of 1.28, sensitivity of 65.8%, and specificity of 88.2%. Conclusion Task-induced attentional states were associated with differences in deqi intensity. Exploratory complementary analyses suggested that D 2 may serve as a physiological index related to attentional engagement and outcomes involving deqi .