Clocking the conduction velocity of the visual pathway with optically pumped magnetometers

Introduction

The human visual pathway carries high volumes of information from the retina to distant regions of the visual cortex. The speed of this information transfer, retinocortical conduction time, has been proposed as a diagnostic measure of neurodegeneration.

Background

This conduction time has typically been estimated based on relatively slow evoked responses. However, we now know that high-frequency activity in both the retina and visual cortex precedes slower evoked responses by several tens of milliseconds.

Timing Differences

In addition, the difference in timing between the onset of high-frequency activity in the retina and cortex is more in line with the expected conduction velocities of the heavily myelinated visual pathway.

Project Proposal

This project proposes to develop and validate a new sensor technology, optically pumped magnetometers (OPMs), to measure this high-frequency retinocortical conduction time. The goal is to establish a diagnostic suitable for patients in the neurology and eye clinics to assess disease progression.

Expected Impacts

Impacts to myelination, circulation, and neural connectivity are all expected to reduce the conduction speed of the visual pathway, even before visual symptoms become apparent.

Advantages of the Proposed Technique

The proposed high-frequency conduction time technique should provide a more accurate and sensitive measure to detect these impacts, with high potential for translation into a clinical diagnostic method.

Measurement Procedure

We will furthermore streamline the measurement procedure to increase the comfort, duration, and feasibility for potential patient groups.