Open AccessCardiorespiratory effects on default‐mode network activity as measured with fMRI
Author(s) -
van Buuren Mariët,
Gladwin Thomas E.,
Zandbelt Bram B.,
van den Heuvel Martijn,
Ramsey Nick F.,
Kahn René S.,
Vink Matthijs
Publication year - 2009
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.20729
Subject(s) - default mode network , resting state fmri , heartbeat , cardiorespiratory fitness , neuroscience , task (project management) , heart rate , cognition , psychology , brain activity and meditation , premovement neuronal activity , medicine , computer science , electroencephalography , computer security , management , blood pressure , economics
Abstract The default‐mode network (DMN) consists of areas showing more activation during rest than during a task. Several authors propose some form of cognitive processing to underlie BOLD signal changes in the DMN as activity within the network is modulated by the level of effort required by the task and is positively correlated with self‐referential processing. Alternatively, BOLD signal changes within the DMN may be caused by cardiorespiratory processes (CR) affecting BOLD signal measurements independent of neuronal activity. The goal of this study is to investigate whether BOLD signal changes within the DMN can be explained by CR effects. To this aim, brain activity, heartbeat, and respiration are measured during resting‐state and while subjects perform a cognitive task with a high‐ and low‐demand condition. To correct for CR effects we used RETROICOR (Glover et al., [ 2000]: Magn Reson Med 44:162–167) in combination with additive linear modeling of changes due to respiration volume, heart rate and heart rate variability. CR effects were present within the frequency‐range of the DMN and were located in areas of the DMN, but equally so in other areas. After removal of CR effects, deactivation and resting‐state connectivity between the areas of the DMN remained significant. In addition, DMN deactivation was still modulated by task demand. The same CR correction method did remove activation in task‐related areas. We take these results to indicate that the BOLD signal within the DMN cannot be explained by CR effects alone and is possibly related to some form of cognitive neuronal processing. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.