Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.11.19.390492v1?rss=1 Authors: Tang, R., Etzel, J. A., Kizhner, A., Braver, T. S. Abstract: The ability to flexibly adapt thoughts and actions in a goal-directed manner appears to rely on cognitive control mechanisms that are strongly impacted by individual differences. A powerful research strategy for investigating the nature of individual variation is to study monozygotic (identical) twins. Clear evidence of twin similarity effects have been observed in prior behavioral and neuroimaging studies, yet within the domain of cognitive control, the specificity and neural underpinnings of this similarity remains elusive. Here, we utilize a multi-task, within-subjects event-related neuroimaging design (with fMRI) to investigate twin effects through multivariate pattern similarity analyses. We focus on a set of fronto-parietal brain parcels exhibiting consistently increased activation associated with cognitive control demands across four task domains: selective attention, context processing, multi-tasking, and working memory. In these parcels, healthy young adult male and female monozygotic twin pairs had similar activation patterns, reliably in all tasks, a finding not observed in unrelated pairs. Twin activation pattern similarity effects were clearest under high control demands, were not present in a set of task-unrelated parcels, and were primarily observed during the within-trial timepoints in which the control demands peaked. Together, these results indicate that twin similarity in the neural representation of cognitive control may be domain-general but also functionally and temporally specific in relation to the level of control demand. The findings suggest a genetic and/or environmental basis for individual variation in cognitive control function, and highlight the potential of twin-based neuroimaging designs for exploring heritability questions within this domain. Copy rights belong to original authors. Visit the link for more info