Dynamic network dysfunction in cocaine dependence: Graph theoretical metrics and stop signal reaction time

Abstract

Graphic theoretical metrics have become increasingly popular in characterizing functional connectivity of neural networks and how network connectivity is compromised in neuropsychiatric illnesses. Here, we add to this literature by describing dynamic network connectivities of 78 cocaine dependent (CD) and 85 non-drug using healthy control (HC) participants who underwent fMRI during performance of a stop signal task (SST). Compared to HC, CD showed prolonged stop signal reaction time (SSRT), consistent with deficits in response inhibition. In graph theoretical analysis of dynamic functional connectivity, we examined temporal flexibility and spatiotemporal diversity of 14 networks covering the whole brain. Temporal flexibility quantifies how frequently a brain region interacts with regions of other communities across time, with high temporal flexibility indicating that a region interacts predominantly with regions outside its own community. Spatiotemporal diversity quantifies how uniformly a brain region interacts with regions in other communities over time, with high spatiotemporal diversity indicating that the interactions are more evenly distributed across communities. Compared to HC, CD exhibited decreased temporal flexibility and increased spatiotemporal diversity in the great majority of neural networks. The graph metric measures of the default mode network negatively correlated with SSRT in CD but not HC. The findings are consistent with diminished temporal flexibility and a compensatory increase in spatiotemporal diversity, in association with impairment of a critical executive function, in cocaine addiction. More broadly, the findings suggest that graph theoretical metrics provide new insights for connectivity analyses to elucidate network dysfunction that may elude conventional measures.

Classification of cocaine‐dependent participants with dynamic functional connectivity from functional magnetic resonance imaging data

“…Networks found with ICA have been further used to study DFC characteristics in schizophrenia patients both with task (auditory oddball task) (Sakoglu & Calhoun, ; Sakoglu et al, ) and at rest (Sakoğlu & Calhoun, ; Sakoğlu, Michael, & Calhoun, ). To our knowledge, there is currently only one other published study using DFC analysis of fMRI datasets in cocaine dependence; Zhang, Zhang, et al () recently studied network dysfunction in cocaine dependence using graph theoretical analysis. There have been many static functional connectivity analyses of cocaine dependence.…”

“…Furthermore, the tracking SST is particularly challenging since it is titrated to the inhibitory performance of the participant. Nonetheless, since response inhibition is highly relevant in substance abuse and addiction, both tasks are widely used in neuroimaging of substance abuse and addiction (Ahmadi et al, 2013; Wang et al, 2018; Zhang, Zhang, et al, 2018) since they assess how well a participant can inhibit his/her response and functional neuroimaging methods such as fMRI during the performance of these tasks can capture brain regions’ responses that mediate inhibitory control, such as inferior frontal cortex, sensorimotor area, subthalamic nucleus, more consistently than the go/no-go task (Rubia, Smith, Brammer, & Taylor, 2003; Zhang & Li, 2012). Combining dynamic functional connectivity (DFC) with a task that is more closely aligned with the phenotypic cognitive deficit of impulse control is also more meaningful than using resting-state data.…”

“…Recently, ICA has been used in studying cocaine dependence. For example, Zhang, Zhang, et al (2018) studied dynamics of functional connectivity to address differences between cocaine-dependent and non-drug-using individuals using a graph theoretical framework. There are also earlier ICA studies using SST in healthy participants (Zhang & Li, 2012; Zhang et al, 2015) and more recent ICA studies of the SST in cocaine-dependent people (Wang et al, 2018).…”

Integration of Neural Reward Processing and Appetite‐Related Signaling in Obese Females: Evidence From Resting‐State fMRI

“…The selected reward‐related nodes are shown in Table . Some of these seed nodes were defined as the functionally based nodes in previous similar fMRI studies . The voxels size and MNI space was defined according to Power's 264‐node atlas.…”

Time varying connectivity across the brain changes as a function of nicotine abstinence state

“…Thus, we predict that the external perturbations of and stress induced by acute abstinence in SUD will be associated with reduced TVC.To date most TVC studies have interrogated data from healthy individuals, and demonstrate reductions in TVC associated with poorer behavioral performance 31,38-40 and increased negative affect 41 . Consistent with these affective and behavioral disruptions, a small but growing literature on SUD-related change in dynamic TVC has begun to appear [42][43][44][45] . These…”