# MDMA modulates human sensorimotor cortical pathways during gentle touch

## TL;DR

MDMA increases the pleasantness of touch and affects brain activity in sensorimotor areas and motion perception regions.

## Contribution

This study reveals how MDMA modulates neural pathways during touch, particularly in sensorimotor and motion-related brain regions.

## Key findings

- MDMA increased affective ratings of touch and plasma oxytocin levels compared to placebo.
- Primary sensorimotor areas showed greater activity during MDMA for both touch speeds.
- Oxytocin levels interacted with drug effects in the occipitotemporal area MT+.

## Abstract

The stimulant ± 3,4-methylenedioxymethamphetamine (MDMA) has been shown to enhance the perceived pleasantness of touch. However, the underlying neural processes contributing to touch-related effects of MDMA are not well understood. Using a double-blind, randomized, within-subject design, this study used fMRI to examine hemodynamic changes following MDMA (1.5 mg/kg) vs. lactose placebo administration during gentle touch stimulation in a healthy sample (N= 18). Participants were stroked on the forearm at a slower, more pleasant (3 cm/s), and a faster (30 cm/s), less pleasant speed. For the MDMA session, participants’ affective ratings of touch stimulation were higher than their placebo ratings. Increase in plasma oxytocin (OT) levels was also greater during the MDMA session. On the neural level, primary sensorimotor areas showed greater hemodynamic changes during the MDMA than during the placebo session for both touch speeds, indicating a relatively early influence within somatosensory pathways. Changes in OT levels showed an interaction with drug in an occipitotemporal region, area MT+, associated with motion perception. However, posterior insula did not show preferential activation for the slower stroking speed. These initial findings provide a basis for extending our knowledge of the neural processes underlying the effect of MDMA on affective touch.