Attention: an evolving construct.

We review the implications of large-scale brain systems on the construct of attention by first focusing on significant theories and discoveries during the previous 150 years and then considering how the comparatively recent discovery of large-scale brain systems may render previous conceptualizations of attention outdated. Seven functional brain networks are briefly reviewed and the implications of emerging principles of brain functioning for test construction and neuropsychological evaluation are considered. To remain a relevant discipline moving into the 21st century, the field of neuropsychology needs to apply the principles that have been discovered about brain networks to better inform our understanding of attention as well as our ever-refining evaluation of this construct.

Structure and function of large-scale brain systems.

This article introduces the functional neuroanatomy of large-scale brain systems. Both the structure and functions of these brain networks are presented. All human behavior is the result of interactions within and between these brain systems. This system of brain function completely changes our understanding of how cognition and behavior are organized within the brain, replacing the traditional lesion model. Understanding behavior within the context of brain network interactions has profound implications for modifying abstract constructs such as attention, learning, and memory. These constructs also must be understood within the framework of a paradigm shift, which emphasizes ongoing interactions within a dynamically changing environment.

The small-world organization of large-scale brain systems and relationships with subcortical structures.

Brain structure and function is characterized by large-scale brain systems. However, each system has its own "small-world" organization, with sub-regions, or "hubs," that have varying degrees of specialization for certain cognitive and behavioral processes. This article describes this small-world organization, and the concepts of functional specialization and functional integration are defined and explained through practical examples. We also describe the development of large-scale brain systems and this small-world organization as a sensitive, protracted process, vulnerable to a variety of influences that generate neurodevelopmental disorders.

Large-scale brain systems and subcortical relationships: the vertically organized brain.

This article reviews the vertical organization of the brain. The cortico-basal ganglia and the cerebro-cerebellar circuitry systems are described as fundamental to cognitive and behavioral control. The basal ganglia anticipate and guide implicitly learned behaviors on the basis of experienced reward outcomes. The cerebellar-cortical network anticipates sensorimotor outcomes, allowing behaviors to be adapted across changing settings and across contexts. These vertically organized systems, operating together, represent the underpinning of cognitive control. The medial temporal lobe system, and its development, is also reviewed in order to better understand how brain systems interact for both implicit and explicit cognitive control.

Large-scale brain systems and subcortical relationships: practical applications.

This article describes an interactive paradigm for understanding brain functioning. This model requires both explicit and implicit learning processes. This paradigm is illustrated through the interpretation of practical examples of behavior. Applications of current neuropsychological tests are presented within this interactive paradigm. The development of new neuropsychological tests is presented, as derived from experimental test paradigms that evaluate implicit learning processes.