Oxytocin Effects on Self Versus Other Touch

The Effects of Orally Administered Oxytocin on Behavioral and Neural Responses to Self Versus Other Touch Distinction

The main aim of the study is to investigate the modulatory effects of oxytocin (24IU) administered orally using medicated lollipops on the behavioral and neural responses to touching yourself compared with being touched by others.

In a double-blind placebo-controlled within-subject experimental design, 40 adult male subjects will be randomly allocated to either receive oral oxytocin (24IU, medicated lollipop) or placebo (lollipop without oxytocin). Starting 45 minutes after treatment a resting state functional magnetic resonance imaging (fMRI) will be recorded (8min) and next subjects will be applied two different types of stroking touch (self- vs. other-produced touch) to their left arm repeated in 16 blocks. After each block of applied touch stimulation, subjects will be required to rate their perceived pleasantness of touch from -4 (extremely unpleasant) to 4 (extremely pleasant). The neural basis of touch processing will be measured via simultaneously acquired fMRI.

To control potential confounding effects among subjects, before the experiment all participants will be asked to complete a range of Chinese versions of validated questionnaires on personality, traits, attitude towards interpersonal touch and interoceptive ability: Autism Spectrum Quotient (ASQ), Beck Depression Inventory II (BDI), State-Trait Anxiety Inventory (STAI), Social Touch Questionnaire (STQ),Sensory Over-Responsivity (SensOR) Scales, Interpersonal Reactivity Index (C-IRI), Self-Concept Clarity Scale (SCCS), Interoceptive Confusion Questionnaire(ICQ) and Multidimensional Assessment of Interoceptive Awareness(MAIA) scale. Additionally, to control for potential confounding effects of treatment on mood across the experiment, the Positive and Negative Affect Schedule (PANAS) will be administered immediately before and 30 minutes after the treatment. Participants will also complete the PANAS after the touch stimulations to further measure the modulatory effects of touch on mood.

Inclusion Criteria:

• Healthy subjects without any past or present psychiatric or neurological disorders and without any current psychotherapeutic medication.

Exclusion Criteria:

• Any history of brain injury, psychiatric/physical illness, alcohol/substance abuse, or other major health concern.