The subsequent interruptive effects of pain on attention

Background Pain is known to interrupt attentional performance selectively. In a previous study, we showed that the interruptive effect of thermal pain on attention could persist up to 1500 ms after painful stimulus offset, but whether the pain modality affects this subsequent interruptive effect remains unclear. Methods The present study was conducted to determine the time course of the interruptive effect of electrically induced pain on orienting and executive attention using various intervals between electric stimulation and attentional tasks (0, 250, 500, 750, 1000, 1250 and 1500 ms) and three study groups (pain, non-pain and control). We performed two separate experiments in which participants performed a spatial cue task (Experiment 1) and the Stroop task (Experiment 2). Participants in the pain and non-pain groups received brief electric somatosensory stimulation, and those in the control group received no physical stimulus. We compared the performance of the three groups under the interstimulus interval (ISI) conditions. Results The impairment of orienting attention prevailed under the first six ISI conditions in the pain and non-pain groups (F-2,F- 63 = 5.72, p < 0.01); executive attention was not affected (F-1,F-66 = 1.64, p = 0.20), confirming the persistence of the interruptive effect after stimulus offset. Conclusions This study demonstrated the interruptive effect of somatic stimulation on subsequent orienting attention performance, with no effect on executive attention. These findings suggest that pain has differential effects on the components of attention, depending on its modality and salience. Significance This study confirmed that pain had a selective subsequent interruptive effect on attention and found that the time course of the interruption depended on the modality of pain and the component of attention