Authors: Andrews‐Hanna, J. R., Smallwood, J., & Spreng, R. N.
Title: The default network and self‐generated thought: component processes, dynamic control, and clinical relevance
Summary: It is frequently suggested that neuroscience is still in its infancy, this becomes patently clear when you start to consider how little we know about the default mode network (DMN). The DMN, also known as the default network (DN) or the task-negative network (TNN) is most active when humans are in a resting state. In short, the DMN is the network that takes over when we are not actively engaged in a specific task. Surprisingly it was assumed that the brain was resting when not engaged in an externally focussed activity. This assumption was surprising because scientists know that their brains are capable of complex processes such as mind wandering when they are not reacting to the external environment. However, only when it was demonstrated that functional brain activity could reach similar levels in task and non-task modes did the investigation into the DMN begin in earnest. This has particular relevance for meditators and contemplative science, as the DMN is often the direct and indirect target for meditation methods.
Andrews‐Hanna, Smallwood and Spreng produced a review of the leading findings linked to the DMN, which they describe as an anatomically diffuse global network. Their primary focus is the DMN and self-generated thought, thought that arise without external sensory stimulus. Describing much of the recent research in the field they conclude that the DMN plays an integrated role in a wide range of neurological functions. Thus both normal and abnormal mental health is dependent on activity and functional connectivity within the DMN and links to other neural networks. The paper provides a useful background to contemplative scientists looking for an understanding of how meditation might influence human behaviour.