Default But Not Rest: Topological Discrimination Defines the Default Mode Network
Summary
AI-generated from the abstractA task-related cortical network, the Topological Discrimination Network (TDN), was discovered by contrasting brain activations from topological discrimination tasks with local geometric discrimination tasks. The TDN and the default mode network (DMN) consist of essentially the same brain regions, and the fMRI response of topological discrimination in those regions exhibited consistent temporal dynamics with resting state. The robustness of the TDN is supported by multiple experiments at different field strengths (3T and 7T MRI) and different signals (BOLD and CBF). The results suggest that topological discrimination could almost be considered a functional default mode of the brain, defining a functional baseline with consistency across participants and sessions.
Study at a glance
| Characteristics | Experimental study |
|---|---|
| Population | Human participants |
| Interventions | topological discrimination tasks local geometric discrimination tasks |
| Key finding | The Topological Discrimination Network (TDN) and the default mode network (DMN) consist of essentially the same brain regions, and topological discrimination fMRI responses in those regions show consistent temporal dynamics with resting state. |
Abstract
Abstract The default mode network (DMN), a set of transmodal cortical regions, has historically been argued to serve the internal functions of brain. The discovery of this network highlighted the brain’s intrinsic operations. The DMN generally decreases its activity during tasks and increases its activity during relaxed non-task states. It is important to investigate the nature of the DMN in order to understand the human brain in health and disease. In the current study, we discovered a task-related cortical network we called the Topological Discrimination Network (TDN), which was consistently revealed by contrasting activations from topological discrimination tasks with local geometric discrimination tasks. The TDN and the DMN consist of essentially the same group of brain regions and the fMRI response of topological discrimination in those regions exhibited consistent temporal dynamics with resting state. The robustness of the TDN is supported by multiple experiments performed at different field strengths (3T and 7T MRI scanner) as well as different types of signals measured (BOLD and CBF). The collective results suggest that the process of topological discrimination could almost be considered as a functional “default mode” of our brain. The TDN, like the DMN, could define the functional baseline of brain, with the advantage of functional consistency across participants and experimental sessions.