Blood Oxygen Level Dependent (BOLD) fMRI is a common technique for measuring brain
activation that could be affected by low-level carbon monoxide (CO) exposure from e.g. smoking.
This study aimed to probe the vulnerability of BOLD fMRI to CO and determine whether it may
constitute a significant neuroimaging confound. Low-level (6ppm exhaled) CO effects on BOLD
response were assessed in 12 healthy never-smokers on two separate experimental days (CO
and air control). fMRI tasks were breath-holds (hypercapnia), visual stimulation and fingertapping.
BOLD fMRI response was lower during breath holds, visual stimulation and fingertapping in the
CO protocol compared to the air control protocol. Behavioural and physiological measures
remained unchanged. We conclude that BOLD fMRI might be vulnerable to changes in baseline
CO, and suggest exercising caution when imaging populations exposed to elevated CO levels.
Further work is required to fully elucidate the impact on CO on fMRI and its underlying
Bendell, CarolineMoosavi, Shakeeb H. Herigstad, Mari
Department of Biological and Medical Sciences
Year of publication: 2019Date of RADAR deposit: 2019-10-17