Emotional modulation of autonomic responses to painful trigeminal stimulation

Dysregulation of supraspinal pain modulation may contribute to chronic pain, including head/face pain. Our laboratory has shown that emotional picture-viewing reliably modulates subjective and physiological pain responses to noxious extracranial (sural nerve) stimulation, suggesting this is a valid method of studying supraspinal modulation. However, to study head/face pain, it is important to determine whether responses evoked by trigeminal stimulation are also modulated. In the present study (34 healthy participants), emotionally-charged pictures (unpleasant, neutral, pleasant) were presented during which painful trigeminal stimulations were delivered during and in between pictures. Autonomic responses to each shock (pain-evoked HR acceleration, pain-evoked skin conductance response [SCR]) were recorded. Consistent with research on extracranial pain, autonomic responses were larger during unpleasant pictures and smaller during pleasant pictures, with linear trends explaining 23% of the variance in pain-evoked HR and 35% of the variance in pain-evoked SCR (ps < .05). Implications for studying cranial pain are discussed.