The relationship between spatial configuration and functional connectivity of brain regions

Abstract

Brain connectivity is often considered in terms of the communication between functionally distinct brain regions. Many studies have investigated the extent to which patterns of coupling strength between multiple neural populations relates to behavior. For example, studies have used "functional connectivity fingerprints" to characterise individuals' brain activity. Here, we investigate the extent to which the exact spatial arrangement of cortical regions interacts with measures of brain connectivity. We find that the shape and exact location of brain regions interact strongly with the modelling of brain connectivity, and present evidence that the spatial arrangement of functional regions is strongly predictive of non-imaging measures of behaviour and lifestyle. We believe that, in many cases, cross-subject variations in the spatial configuration of functional brain regions are being interpreted as changes in functional connectivity. Therefore, a better understanding of these effects is important when interpreting the relationship between functional imaging data and cognitive traits.

Possible Biological Mechanisms Linking Mental Health and Heat—A Contemplative Review

“…However, as most of the brain’s functions are based on coordinated interactions of large numbers of neurons distributed across different brain areas, the second concept, connectivity, is of increasing interest for both psychiatrists and neuroscientists. Connectivity analyses investigate the way in which brain regions communicate with one another [ 87 ]. The methods that are used for studying brain connectivity largely depend on the type of connectivity of interest.…”

“…In rs-fMRI studies, participants are not required to perform any motor or cognitive task or to pay attention to any particular stimulus, but are instead instructed to clear their minds and not to engage in specific thoughts or visual images [ 83 ]. Rs-fMRI functional connectivity analyses thus revolve around detecting temporally correlated BOLD signals from distinct regions of the brain in the absence of any cognitive task [ 83 , 87 ]. Alterations in resting-state functional connectivity were shown to be associated with a wide variety of brain and behavioral disorders, such as attention deficit hyperactivity disorder (ADHD) [ 91 ], Alzheimer’s disease [ 92 ], obsessive compulsive disorder [ 93 ], depression [ 94 ], bipolar disorder [ 95 ], and schizophrenia [ 96 ].…”

The situation or the person? Individual and task‐evoked differences in BOLD activity

“…This finding should not be surprising, given that there is much more variability in the fine‐scale structure of the human cortex, as opposed to its large‐scale arrangement. While comparing whole‐brain activation patterns at lower ROI resolution reduces the dimensionality of the comparison, it also acts as a spatial smoothing operation, reducing potential small differences in the anatomical location of functional areas (Bijsterbosch et al, ; Mikl et al, ). Thus, increasing the parcellation resolution (e.g., 800 ROI parcellation or vertex‐level) would reduce the extent of this implicit smoothing, thereby potentially increasing inter‐subject variability of whole‐brain activation patterns.…”

Effects of resting state condition on reliability, trait specificity, and network connectivity of brain function measured with arterial spin labeled perfusion MRI

“…Resting state fMRI (rs-fMRI) reveals the intrinsic brain activity unrelated to a specific cognitive of sensorimotor task and it is now widely used to characterize the state and trait effects of brain function ( Matthews et al, 2006 ; Sorg et al, 2007 ; Fox and Raichle, 2007 ; Raichle, 2015 ; Bijsterbosch et al, 2017 ; Detre et al, 2009 , 2012 ). Because r esting-state fMRI requires minimal subject engagement, it can easily be acquired in a variety of populations including patients ( Power et al, 2014 ) and, in contrast to task fMRI, can address brain function broadly across multiple domains as subserved by differing brain regions and networks.…”

“…Two rs-fMRI techniques, blood oxygen level dependent (BOLD) MRI and arterial spin labeled (ASL) perfusion MRI, have been most commonly used to measure resting brain function. Whereas rs-fMRI based on BOLD contrast detects spatial correlations in spontaneous fluctuations of brain activity as manifested in BOLD signal revealing distributed networks ( Fox and Raichle, 2007 ; Raichle, 2015 ; Bijsterbosch et al, 2017 ), it is challenging to interpret the magnitude of resting brain activity since BOLD signal intensity does not provide absolute quantification of cerebral blood flow (CBF) or metabolism. In contrast, ASL MRI can measure resting function directly at the voxel level using magnetically labeled arterial blood water as an endogenous diffusible tracer for quantification of regional CBF ( Detre et al, 2009 , 2012 ), which is thought to be coupled to regional neural activity ( Raichle, 1998 ).…”