Pain affects the lives of many individuals by creating physical, psychological, and economic burdens. A critical psychological factor negatively affected by pain is one’s ability to sustain attention. In order to better understand the effect of pain on sustained attention we conducted three experiments utilizing the psychomotor vigilance task, thought probes, and pupillometry. In Experiment 1, participants in acute pain exhibited overall poorer task performance. However, this effect was localized to the relative frequency and duration of the participants' slowest responses with their faster responses being equivalent to a no-pain control group. In Experiment 2, we replicated the procedure and included periodic thought probes to overtly measure subjective experiences during the task. Participants in pain reported fewer ‘on-task’ thoughts and more exteroceptive thoughts directed toward the source of their pain. In Experiment 3, we replicated the procedure while simultaneously tracking pupillary dynamics using an eye-tracker. Participants in pain had smaller task-evoked pupillary responses, which is thought to be an indicator of task engagement. Taken together, pain led to poorer performance on the psychomotor vigilance task, an increase in the relative frequency and extremeness of slow responses, increases in off-task thoughts, and reductions in a physiological indicator of task engagement. These data speak to theories of how pain competes with task goals for attention and negatively impacts behavior. The broader implications of this work are the identification of a low-level mechanism by which pain can interfere with normal cognitive functioning.
Acute pain impairs sustained attention
