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 children's 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.

With food in mind

“…Another interesting avenue for future research is to examine neural representations of actual food intake, by delivering liquid food stimuli while participants are in the MRI scanner using a gustometer. A gustometer is a MRI-compatible device using pumps to delivers small amounts of liquid foods to the participant's mouth through plastic tubing (e.g., Andersen et al, 2019;Canna et al, 2019;Christensen et al, 2022;Tord et al, 2021). Finally, functional connectivity mutivoxel pattern analsysis (fc-MVPA) could be used on fMRI data to study connectivity between multivoxel patterns in different regions (e.g., Assouline, 2023;Kahathuduwa et al, 2018;McNorgan et al, 2020;Richiardi et al, 2011;Smith, 2012;Wen et al, 2019).…”