Time-resolved effective connectivity in task fMRI: Psychophysiological interactions of Co-Activation patterns

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2020-05, Vol.212, p.116635-116635, Article 116635
• Main Authors: Freitas, Lorena G.A., Bolton, Thomas A.W., Krikler, Benjamin E., Jochaut, Delphine, Giraud, Anne-Lise, Hüppi, Petra S., Van De Ville, Dimitri
• Format: Article
• Language: English
• Subjects: Adult; Brain; Brain - physiology; Brain Mapping; Brain Mapping - methods; Co-activation patterns (CAPs); Cognition; Cognition - physiology; Cognitive ability; Cognitive science; Cognitive Sciences; Cortex (cingulate); Dynamic functional connectivity (dFC); Female; Framewise analysis; Functional magnetic resonance imaging; Humans; Image Processing, Computer-Assisted; Image Processing, Computer-Assisted - methods; Information processing; Life Sciences; Magnetic Resonance Imaging; Magnetic Resonance Imaging - methods; Male; Methods; Models, Neurological; Neural networks; Neural Pathways; Neural Pathways - physiology; Neuroimaging; Neurons and Cognition; Neuroscience; Polarity; PPI-CAPs; Psychophysiological interaction (PPI); Psychophysiology; Task fMRI; Young Adult
• ISSN: 1053-8119; 1095-9572; 1095-9572
• DOI: 10.1016/j.neuroimage.2020.116635

Investigating context-dependent modulations of Functional Connectivity (FC) with functional magnetic resonance imaging is crucial to reveal the neurological underpinnings of cognitive processing. Most current analysis methods hypothesise sustained FC within the duration of a task, but this assumption has been shown too limiting by recent imaging studies. While several methods have been proposed to study functional dynamics during rest, task-based studies are yet to fully disentangle network modulations. Here, we propose a seed-based method to probe task-dependent modulations of brain activity by revealing Psychophysiological Interactions of Co-activation Patterns (PPI-CAPs). This point process-based approach temporally decomposes task-modulated connectivity into dynamic building blocks which cannot be captured by current methods, such as PPI or Dynamic Causal Modelling. Additionally, it identifies the occurrence of co-activation patterns at single frame resolution as opposed to window-based methods. In a naturalistic setting where participants watched a TV program, we retrieved several patterns of co-activation with a posterior cingulate cortex seed whose occurrence rates and polarity varied depending on the context; on the seed activity; or on an interaction between the two. Moreover, our method exposed the consistency in effective connectivity patterns across subjects and time, allowing us to uncover links between PPI-CAPs and specific stimuli contained in the video. Our study reveals that explicitly tracking connectivity pattern transients is paramount to advance our understanding of how different brain areas dynamically communicate when presented with a set of cues. •PPI-CAPs is a method for dynamic task-based effective connectivity.•Sparse moments of seed (de)activation show task-based changes in brain connectivity.•K-means++ clustered fMRI frames decompose Psychophysiological Interaction effects.•Moment-to-moment patterns of co-activation with a seed are linked to movie cues.