Functional Imaging with Reinforcement, Eyetracking, and Physiological Monitoring

Summary

This presentation demonstrates the use of fMRI to study neural circuits that underlie decision-making. Simple perceptual tasks are combined with appetitive and aversive reinforcements to investigate how outcomes affect decision processes.

Abstract

We use functional brain imaging (fMRI) to study neural circuits that underlie decision-making. To understand how outcomes affect decision processes, simple perceptual tasks are combined with appetitive and aversive reinforcement. However, the use of reinforcers such as juice and airpuffs can create challenges for fMRI. Reinforcer delivery can cause head movement, which creates artifacts in the fMRI signal. Reinforcement can also lead to changes in heart rate and respiration that are mediated by autonomic pathways. Changes in heart rate and respiration can directly affect the fMRI (BOLD) signal in the brain and can be confounded with signal changes that are due to neural activity. In this presentation, we demonstrate methods for administering reinforcers in a controlled manner, for stabilizing the head, and for measuring pulse and respiration.

Protocol

Equipment Setup

The first step in running and fMRI experiment is setting up and checking the equipment.  These steps can be done in any order.

Signal conditioning - The scanner is located in an electrically and magnetically shielded room.  All electrical signals going from the control room to the scanner room pass through a filter panel to remove any frequencies that could create an artifact in the MR image.

Airpuff – The airpuff device delivers a controlled puff of fixed pressure and duration.  When directed toward the eye, this is aversive but non-traumatic.  ....