A method for removal of global effects from fMRI time series

Macey, Paul M; Macey, Katherine E.; Kumar, Rajesh; Harper, Ronald M.

doi:10.1016/j.neuroimage.2003.12.042

Cited by 390 publications

(323 citation statements)

References 21 publications

Supporting

Mentioning

317

Contrasting

Order By: Relevance

“…Separate regressors were constructed by convolving the box‐car function of each condition with the canonical hemodynamic response function. In addition to task regressors, a nuisance covariate of the whole‐brain mean signal was used to account for the global BOLD signal fluctuations induced by changes in P CO2 [Birn et al, 2006; Macey et al, 2004]. …”

Section: Methodsmentioning

confidence: 99%

Brain activity and connectivity during poetry composition: Toward a multidimensional model of the creative process

Liu

Erkkinen

Healey

et al. 2015

Human Brain Mapping

182

102

View full text Add to dashboard Cite

Creativity, a multifaceted construct, can be studied in various ways, for example, investigating phases of the creative process, quality of the creative product, or the impact of expertise. Previous neuroimaging studies have assessed these individually. Believing that each of these interacting features must be examined simultaneously to develop a comprehensive understanding of creative behavior, we examined poetry composition, assessing process, product, and expertise in a single experiment. Distinct activation patterns were associated with generation and revision, two major phases of the creative process. Medial prefrontal cortex (MPFC) was active during both phases, yet responses in dorsolateral prefrontal and parietal executive systems (DLPFC/IPS) were phase‐dependent, indicating that while motivation remains unchanged, cognitive control is attenuated during generation and re‐engaged during revision. Experts showed significantly stronger deactivation of DLPFC/IPS during generation, suggesting that they may more effectively suspend cognitive control. Importantly however, similar overall patterns were observed in both groups, indicating the same cognitive resources are available to experts and novices alike. Quality of poetry, assessed by an independent panel, was associated with divergent connectivity patterns in experts and novices, centered upon MPFC (for technical facility) and DLPFC/IPS (for innovation), suggesting a mechanism by which experts produce higher quality poetry. Crucially, each of these three key features can be understood in the context of a single neurocognitive model characterized by dynamic interactions between medial prefrontal areas regulating motivation, dorsolateral prefrontal, and parietal areas regulating cognitive control and the association of these regions with language, sensorimotor, limbic, and subcortical areas distributed throughout the brain. Hum Brain Mapp 36:3351–3372, 2015. © 2015 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc..

show abstract

Section: Methodsmentioning

confidence: 99%

Brain activity and connectivity during poetry composition: Toward a multidimensional model of the creative process

Liu

Erkkinen

Healey

et al. 2015

Human Brain Mapping

182

102

View full text Add to dashboard Cite

show abstract

“…Finally, linear regression of mean global BOLD signal, mean ventricular BOLD signal and mean white matter BOLD signals from each voxel was performed. Even if it is still a debated question, it could be argued that global signal regression (Macey et al 2004) could induce spurious correlations in our analysis [e.g., (Murphy et al 2009)]. However, it has been shown in Honey et al 2009) that global signal regression is an important step to better reveal the correlation between structural and functional connectivities.…”

Section: Bold Acquisitionmentioning

confidence: 99%

Cerebral functional connectivity periodically (de)synchronizes with anatomical constraints

et al. 2015

View full text Add to dashboard Cite

This paper studies the link between restingstate functional connectivity (FC), measured by the correlations of fMRI BOLD time courses, and structural connectivity (SC), estimated through fiber tractography. Instead of a static analysis based on the correlation between SC and FC averaged over the entire fMRI time series, we propose a dynamic analysis, based on the time evolution of the correlation between SC and a suitably windowed FC. Assessing the statistical significance of the time series against random phase permutations, our data show a pronounced peak of significance for time window widths around 20-30 TR (40-60 s). Using the appropriate window width, we show that FC patterns oscillate between phases of high modularity, primarily shaped by anatomy, and phases of low modularity, primarily shaped by inter-network connectivity. Building upon recent results in dynamic FC, this emphasizes the potential role of SC as a transitory architecture between different highly connected restingstate FC patterns. Finally, we show that the regions contributing the most to these whole-brain level fluctuations of FC on the supporting anatomical architecture belong to the default mode and the executive control networks Steven Laureys and Rodolphe Sepulchre contributed equally. Electronic supplementary material 123Brain Struct Funct DOI 10.1007/s00429-015-1083-y suggesting that they could be capturing consciousness-related processes such as mind wandering.

show abstract

“…Instead, a voxel-level linear model of the global signal (LMGS), which has been shown not to introduce bias, was used to remove the global effects (Macey et al, 2004). Group activations were assessed by a random effects analysis.…”

Section: Fmri Analysis-duringmentioning

confidence: 99%

Sleep deprivation alters functioning within the neural network underlying the covert orienting of attention

Mander¹,

Reid²,

Davuluri³

et al. 2008

Brain Research

View full text Add to dashboard Cite

One function of spatial attention is to enable goal-directed interactions with the environment through the allocation of neural resources to motivationally relevant parts of space. Studies have shown that responses are enhanced when spatial attention is predictively biased towards locations where significant events are expected to occur. Previous studies suggest that the ability to bias attention predictively is related to posterior cingulate cortex (PCC) activation (Small et al., 2003). Sleep deprivation (SD) impairs selective attention and reduces PCC activity (Thomas et al., 2000). Based on these findings, we hypothesized that SD would affect PCC function and alter the ability to predictively allocate spatial attention. Seven healthy, young adults underwent functional magnetic resonance imaging (fMRI) following normal rest and 34-36 hours of SD while performing a task in which attention was shifted in response to peripheral targets preceded by spatially informative (valid), misleading (invalid), or uninformative (neutral) cues. When rested, but not when sleep-deprived, subjects responded more quickly to targets that followed valid cues than those after neutral or invalid cues. Brain activity during validly cued trials with a reaction time benefit was compared to activity in trials with no benefit. PCC activation was greater during trials with a reaction time benefit following normal rest. In contrast, following SD, reaction time benefits were associated with activation in the left intraparietal sulcus, a region associated with receptivity to stimuli at unexpected locations. These changes may render sleep-deprived individuals less able to anticipate the locations of upcoming events, and more susceptible to distraction by stimuli at irrelevant locations.

show abstract

A method for removal of global effects from fMRI time series

Cited by 390 publications

References 21 publications

Brain activity and connectivity during poetry composition: Toward a multidimensional model of the creative process

Brain activity and connectivity during poetry composition: Toward a multidimensional model of the creative process

Cerebral functional connectivity periodically (de)synchronizes with anatomical constraints

Sleep deprivation alters functioning within the neural network underlying the covert orienting of attention

Contact Info

Product

Resources

About