AbstractThe 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.Significance StatementCognitive control is indispensable to human adaptability. A critical goal for basic and translational research is to discover the brain basis of the individual differences that clearly characterize this domain. Neuroimaging studies of twins enable exploration of this issue, by identifying similarity and variation in task-evoked neural activity, and testing whether such effects are domain general, but also functionally specific to cognitive control demands. Here, we provide the first evidence of twin similarity in neural activation patterns within fronto-parietal regions, which is present in multiple cognitive control tasks, and selective to peak periods of control demand. These results confirm the domain-generality of neural representations of cognitive control, and support the genetic and/or environmental basis of this source of individual variation.
Frontoparietal pattern similarity analyses of cognitive control in monozygotic twins
