The overall aim of this study is to examine whether oxytocin has a mechanistic effect on pain perception, physical functioning, and physiological and psychological arousal in individuals with chronic musculoskeletal neck and shoulder pain. This study involves receiving a one-off administration of intranasal oxytocin, relative to placebo, to investigate the role of this peptide in pain experience. Oxytocin is a hormone that is produced naturally within the human body. Although it is traditionally known for its role in initiating childbirth and breastfeeding, oxytocin has also been shown to have pain- and anxiety-reducing effects. We expect that oxytocin will help modulate responses to pain-related experiences.