Skip to content

Temporal Dynamics of Activity in Default Mode Network Suggest a Role in Top-Down Processing for Trial Responses

D. Mastrovito, C. Hanson, S. Hanson

preprint DOI: 10.1101/2023.01.08.523152 (opens in new tab)

Relevant Not relevant

Study at a glance

AI-extracted from the abstract
Characteristics Observational neuroimaging analysis (Human Connectome Project data)
Population Human Connectome Project participants
Topics Default mode network
Key findings The authors report that the dorsal DMN shows only a transient initial activity decrease at trial onset that increases over the trial, while the ventral DMN often tracks task-activated areas. They argue that these ramping dynamics contradict a task-negative view of the DMN and propose that its dorsal and ventral subcomponents jointly support bottom-up salience detection and top-down voluntary action.

Abstract

The default mode network (DMN) is a collection of brain regions including midline frontal and parietal structures, medial and lateral temporal lobes, and lateral parietal cortex. Although there is evidence that the network can be subdivided into at least two subcomponents, the network reliably exhibits highly correlated activity both at rest and during task performance. Current understanding regarding the function of the DMN rests on a large body of research indicating that activity in the network decreases during task epochs of experimental paradigms relative to inter-trial intervals. A seeming contradiction arises when the experimental paradigm includes tasks involving autobiographical memory, thinking about one’s self, planning for the future, or social cognition. In such cases, the DMN’s activity increases and is correlated with attentional networks. Some have therefore concluded that the DMN supports advanced human cognitive abilities such as interoceptive processing and theory of mind. This conclusion may be called into question by evidence of correlated activity in homologous brain regions in other, even non-primate, species. Thus, there are contradictory findings related to the function of the DMN that have been difficult to integrate into a coherent theory regarding its function. Using data from the Human Connectome Project, we explore the temporal dynamics of activity in different regions of the DMN in relation to stimulus presentation. We show that generally the dorsal portion of the network exhibits only a transient initial decrease in activity at the start of trials that increases over trial duration. The ventral component often has more similarity in its time course to that of task-activated areas. We propose that task-associated ramping dynamics in the network are incompatible with a task-negative view of the DMN and propose the dorsal and ventral sub-components of network may rather work together to support bottom-up salience detection and subsequent top-down voluntary action. In this context, we re-interpret the body of anatomical and neurophysiological experimental evidence, arguing that this interpretation can accommodate the seeming contradictions regarding DMN function in the extant literature.

Comparable studies

Other experimental studies on default mode network, most cited first.

Study Year Design Participants
Functional connectivity of default mode network components: Correlation, anticorrelation, and causality Healthy subjects 2008 Observational study using resting-state fMRI and seed correlation analysis
Patterns of Brain Activity Supporting Autobiographical Memory, Prospection, and Theory of Mind, and Their Relationship to the Default Mode Network Healthy subjects 2009 Experimental study using fMRI
Dynamic reconfiguration of the default mode network during narrative comprehension Human subjects 2016 Experimental study
Broadband Cortical Desynchronization Underlies the Human Psychedelic State Healthy human participants 2013 Experimental study
The brain on art: intense aesthetic experience activates the default mode network Human observers 2012 Observational study with fMRI and behavioral analysis

Citations in the library

Cites 4

Related reading

Explore topics

Default mode network Meditation