Fronto-parietal homotopy in resting-state functional connectivity predicts task-switching performance

Abstract

Homotopic functional connectivity reflects the degree of synchrony in spontaneous activity between homologous voxels in the two hemispheres. Previous studies have associated increased brain homotopy and decreased white matter integrity with performance decrements on different cognitive tasks across the life-span. Here, we correlated functional homotopy, both at the whole-brain level and specifically in fronto-parietal network nodes, with task-switching performance in young adults. Cue-to-target intervals (CTI: 300 vs. 1200 ms) were manipulated on a trial-by-trial basis to modulate cognitive demands and strategic control. We found that mixing costs, a measure of task-set maintenance and monitoring, were significantly correlated to homotopy in different nodes of the fronto-parietal network depending on CTI. In particular, mixing costs for short CTI trials were smaller with lower homotopy in the superior frontal gyrus, whereas mixing costs for long CTI trials were smaller with lower homotopy in the supramarginal gyrus. These results were specific to the fronto-parietal network, as similar voxel-wise analyses within a control language network did not yield significant correlations with behavior. These findings extend previous literature on the relationship between homotopy and cognitive performance to task-switching, and show a dissociable role of homotopy in different fronto-parietal nodes depending on task demands.

Reduced homotopic interhemispheric connectivity in psychiatric disorders: evidence for both transdiagnostic and disorder specific features

“…Homotopic interhemispheric rsFC of the occipital lobe has been found to be negatively associated with visual long-term memory performance in healthy children (6–10 years old; Gracia-Tabuenca et al ., 2018 ). In young adults, homotopic interhemispheric rsFC of the fronto-parietal network was positively correlated with task-switching performance (Vallesi et al ., 2022 ). Homotopic rsFC of the language network can also predict new language learning performance, although different regions correspond to different aspects of new language learning (Sander et al ., 2022 ).…”

Breakdown of specific functional brain networks in clinical variants of Alzheimer’s disease

“…Overall, these studies reported a consistent vulnerability of the FPN, despite the clinical heterogeneity of EOAD sample (i.e., in these studies, EOAD patients were not characterized by their clinical phenotype). The FPN includes the lateral prefrontal cortex and temporoparietal regions and it has been linked with executive functions (Smith et al, 2009;Laird et al, 2011;Vallesi et al, 2021). The FPN also plays a critical role in coordinating behavior in an accurate and flexible goal-driven manner (Marek and Dosenbach, 2018).…”

Sex differences in brain homotopic co-activations: a meta-analytic study

“…Crucially, HC can be taken as an index of local interhemispheric integration (Jin et al 2020 ). Values of homotopic FC are higher than those of other forms of intra- and interhemispheric FC (Stark et al 2008 ), and it correlates with the performance of cognitive tasks, such as visuospatial attention (Gracia-Tabuenca et al 2018 ) and executive function (Zhao et al 2020 ; Vallesi et al 2021 ). Furthermore, altered patterns of homotopic FC were observed in a wide array of pathologic conditions or abnormal states (Shan et al 2021 ; Yu et al 2018 ; Chen et al 2016 ; Guo et al 2019 ; Deng et al 2021 ; Loomba et al 2021 ; Yao et al 2021 ; Li et al 2015 ; Zhao et al 2017 ).…”