On the origins of the ‘global signal’ determined by functional magnetic resonance imaging in the resting state

Bennett, Maxwell R.; Farnell, L.; Gibson, W.G.; Lagopoulos, Jim

doi:10.1088/1741-2560/13/1/016012

Cited by 5 publications

(4 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This dominant mode of global BOLD co-variance is likely related to what is commonly described as the ‘global signal’ in resting-state fMRI studies, whose neurophysiological origin and role remains unclear 13, 56–59 . Here, we find a clear relationship between the prevalence of FC state #1 and cognitive performance, pointing to a potential role of global BOLD coherence in cognitive processing.…”

Section: Discussionmentioning

confidence: 96%

Cognitive performance in healthy older adults relates to spontaneous switching between states of functional connectivity during rest

Cabral

Vidaurre

Marques

et al. 2017

Sci Rep

315

470

View full text Add to dashboard Cite

Growing evidence has shown that brain activity at rest slowly wanders through a repertoire of different states, where whole-brain functional connectivity (FC) temporarily settles into distinct FC patterns. Nevertheless, the functional role of resting-state activity remains unclear. Here, we investigate how the switching behavior of resting-state FC relates with cognitive performance in healthy older adults. We analyse resting-state fMRI data from 98 healthy adults previously categorized as being among the best or among the worst performers in a cohort study of >1000 subjects aged 50+ who underwent neuropsychological assessment. We use a novel approach focusing on the dominant FC pattern captured by the leading eigenvector of dynamic FC matrices. Recurrent FC patterns – or states – are detected and characterized in terms of lifetime, probability of occurrence and switching profiles. We find that poorer cognitive performance is associated with weaker FC temporal similarity together with altered switching between FC states. These results provide new evidence linking the switching dynamics of FC during rest with cognitive performance in later life, reinforcing the functional role of resting-state activity for effective cognitive processing.

show abstract

Section: Discussionmentioning

confidence: 96%

Cognitive performance in healthy older adults relates to spontaneous switching between states of functional connectivity during rest

Cabral

Vidaurre

Marques

et al. 2017

Sci Rep

315

470

View full text Add to dashboard Cite

show abstract

“…In line with other studies employing the LEiDA method, PL 8 is a state of global phase coherence. This state has been assumed to reflect the global signal ( Bennett et al, 2016 , Cabral et al, 2017 , Keller et al, 2013 ).…”

Section: Resultsmentioning

confidence: 99%

“…Similar to other studies using the LEiDA method, we found a state of global phase coherence in PL 8. While the exact function of this type of state is still unclear, it has been suggested to represent the global signal commonly found in fMRI studies ( Bennett et al, 2016 , Cabral et al, 2017 , Keller et al, 2013 ). Changes in the temporal characteristics of this state have been related to a variety of function and disfunction, including cognitive performance ( Cabral et al, 2017 ), depressive symptoms ( Alonso Martínez et al, 2020 , Figueroa et al, 2019 ), insight ( Larabi et al, 2020 ), and schizophrenia ( Farinha et al, 2022 ).…”

Section: Discussionmentioning

confidence: 99%

Time varying dynamics of hallucinations in clinical and non-clinical voice-hearers

Marschall

Koops

Brederoo

et al. 2023

NeuroImage: Clinical

View full text Add to dashboard Cite

“…This then enables the calculation of the BOLD signal after input of a (scaled) neuronal activity. These equations have been used in a number of investigations of how the BOLD signal arises in neuronal networks (Bennett et al 2015(Bennett et al , 2016Deco et al 2014;Deco and Jirsa 2012;Robinson et al 2006). There is now considerable experimental evidence for negative BOLD signals (Devor et al 2007;Frahm et al 2008;Moraschi et al 2012;Mullinger et al 2014Mullinger et al , 2017Pasley et al 2007;Sadaghiani et al 2009;Shmuel et al 2006), but it is still an open question as to the role played by below-baseline neuronal activity.…”

Section: Introductionmentioning

confidence: 99%

Quantitative relations between transient BOLD responses, cortical energetics, and impulse firing in different cortical regions

Bennett

Farnell

Gibson

2019

Journal of Neurophysiology

View full text Add to dashboard Cite

The blood oxygen level-dependent (BOLD) functional magnetic resonance imaging signal arises as a consequence of changes in blood flow (cerebral blood flow) and oxygen usage (cerebral metabolic rate of oxygen) that in turn are modulated by changes in neuronal activity. Much attention has been given to both theoretical and experimental aspects of the energetics but not to the neuronal activity. Here we use our previous theory relating the steady-state BOLD signal to neuronal activity and amalgamate it with the standard dynamic causal model (DCM, Friston) theory to produce a quantitative model relating the time-dependent BOLD signal to the underlying neuronal activity. Unlike existing treatments, this new theory incorporates a nonzero baseline activity in a completely consistent way and is thus able to account for both positive and negative BOLD signals. It can reproduce a wide variety of experimental BOLD signals reported in the literature solely by adjusting the neuronal input activity. In this way it provides support for the claim that the main features of the signals, including poststimulus undershoot and overshoot, are principally a result of changes in neuronal activity. NEW & NOTEWORTHY A previous model relating the steady-state blood oxygen level-dependent (BOLD) signal to neuronal activity, both above and below baseline, is extended to account for transient BOLD signals. This allows for a detailed investigation of the role neuronal activity can play in such signals and also encompasses poststimulus undershoot and overshoot. A wide variety of experimental BOLD signals are reproduced solely by adjusting the neuronal input activity, including recent results regarding the BOLD signal in patients with schizophrenia.

show abstract

On the origins of the ‘global signal’ determined by functional magnetic resonance imaging in the resting state

Cited by 5 publications

References 55 publications

Cognitive performance in healthy older adults relates to spontaneous switching between states of functional connectivity during rest

Cognitive performance in healthy older adults relates to spontaneous switching between states of functional connectivity during rest

Time varying dynamics of hallucinations in clinical and non-clinical voice-hearers

Quantitative relations between transient BOLD responses, cortical energetics, and impulse firing in different cortical regions

Contact Info

Product

Resources

About