3. Biological - we will take two small saliva (spit) samples from patients to test whether levels of stress hormones such as cortisol are elevated in patients, and whether other immune biomarkers such as pro-inflammatory cytokines TNF-alpha and IL-1 are reduced by pre-surgical stress but maintained when music and art are present. Previous research within the field of psychoneuroimmunology suggests that alterations in psychological stress levels have consequences for biological response (Ader, 2007).