3D printed pacifier-shaped mouthpiece for fMRI-compatible gustometers

Abstract

Gustometers have allowed the delivery of liquids in fMRI settings for decades and mouthpieces are a critical part of those taste delivery systems. Here we propose an innovative 3D printed mouthpiece inspired by childrens pacifiers that allow participants to swallow while lying down in an MRI scanner. Our results validate the effectiveness of our method by showing significant clusters of activation in the insular and piriform cortex which are regions that have been consistently identified to compute taste processing. We used a large sample (n=85) to validate our method. Our mouthpiece fulfills several criteria guarantying a gustatory stimulus of quality, making the delivery more precise and reliable. Moreover, this new pacifier-shaped design is: simple and cheap to manufacture, hygienic, comfortable to keep in mouth, and flexible to diverse use cases.We hope that this new method will promote and facilitate the study of taste and flavor perception in the context of reward processing in affective neuroscience and thus help provide an integrative approach to the study of the emotional nature of rewards.