Pain Perception of Dual-Modal Noxious Stimuli Under the Attentional Prompt

In certain situations, individuals may be simultaneously exposed to two distinct modalities of noxious stimuli. Attention plays a crucial role in shaping pain perception triggered by these stimuli. Pain perception accompanied by attentional modulation remains poorly understood in such scenarios. In two experiments, we administered heat and pressure stimuli separately to the right and left foot to explore pain perception when individuals simultaneously experienced dual-modal noxious stimuli under an attentional prompt. The behavioral experiments observed an inhibitory-like effect of the focused pain on the perception of another unfocused pain when individuals perceived dual-modal noxious stimuli (Experiment 1a); however, no inhibitory-like effect was observed when there was no clear attentional orientation (Experiment 1b). Moreover, the functional magnetic resonance imaging experiment (Experiment 2) further revealed that the inhibitory effects on heat- and pressure-related pain were separately associated with the precentral and postcentral gyri, whereas the caudal anterior cingulate cortex was found to be involved in both inhibition processes. Our findings provide direct behavioral and neural evidence of pain perception in response to dual-modal noxious stimuli, highlighting the significance of directed attention.