Large Scale Brain Systems

Abstract

The concept of large scale brain systems was reviewed in detail in Volume I of this series [2], which described a model of brain-behavior relationships using ADHD as proxy. Seven patterns of connectivity have been identified within the human brain by Yeo and colleagues [35]. These seven connectional systems appear to be very robust since they have been observed with remarkable replicability. The frontoparietal network, or FPN, is engaged during the performance of effortful cognitive tasks that require rules or information to be kept in mind for guiding behavior. This is equivalent to a cognitive control network. The ventral attention network (VAN) supports object identification, which includes contextual salience or aspects of “reward value” by identifying objects and what they are used for. The dorsal attention network (DAN) plays a primary role in the control of spatial attention, including attentional shifting, object location, and information about how objects are used. The VAN and DAN interact with the FPN in goal-directed behavioral control processes, so that in aggregate, these systems transform into an “action control” network. The visual network (VN) supports and interacts with the ventral and dorsal attention networks to sustain attention and to suppress attention to irrelevant stimuli. The sensory motor network (SMN) executes the motor activity programmed by these other systems. The limbic network (LN) interacts with these brain systems for the purpose of generating motivational and reward influences. Finally, the default mode network (DMN) is active when we are “at rest,” doing nothing but thinking, imagining, or dreaming as our mind wanders and drifts. However, as soon as we engage in purposive cognitive tasks or behavior, activity within the DMN diminishes very considerably. The neuroanatomy and functional connectivity profiles of these brain systems, which includes connections with the basal ganglia and cerebellum, defining the vertical organization of the brain, were described in more detail in Volume I. Castellanos and Proal [50] also provide a succinct, useful anatomical and functional summary of these large scale brain systems. (The reader of this paper is very strongly urged to review Volume I of this series [2], and/or the provided references; a comprehensive understanding of these networks, and their dynamic interactions, is absolutely critical for establishing and applying the principles presented in this current volume).KeywordsCurrent VolumeSpatial AttentionDefault Mode NetworkObject LocationBrain SystemThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.