Skip to content

Daniel S. Margulies

7 papers in the library · 1,896 citations · publishing 2016-2021

Papers

The default mode network in cognition: a topographical perspective

Nature reviews. Neuroscience July 5, 2021 Jonathan Smallwood, Boris C. Bernhardt, Robert Leech et al. 970 citations

The default mode network (DMN) is a set of brain regions in the parietal, temporal, and frontal cortex that typically reduce activity during attention-demanding tasks but increase activity during complex cognition linked to memory or abstract thought. These regions are located farthest from sensory and motor systems. The paper considers how knowledge of the DMN's topographic characteristics can be used to better understand its contributions to cognition and behavior.

Default mode network can support the level of detail in experience during active task states

Proceedings of the National Academy of Sciences August 27, 2018 Mladen Sormaz, Charlotte Murphy, Hao-ting Wang et al. 291 citations

The default mode network (DMN), a set of brain regions traditionally linked to off-task or mind-wandering states, actually contributes to detailed, task-relevant cognition during active tasks. Using fMRI, participants performed working-memory tasks while reporting their thoughts. Patterns of neural activity showed that distinctions between on- and off-task thought involved regions near sensory and motor cortex, not the DMN. However, the level of detail in ongoing thought corresponded to activity patterns within the DMN during memory maintenance. These findings indicate the DMN supports detailed cognition under active task conditions, challenging the view that it is solely task-negative.

Distant from input: Evidence of regions within the default mode network supporting perceptually-decoupled and conceptually-guided cognition

NeuroImage January 12, 2018 Charlotte Murphy, Elizabeth Jefferies, Shirley-Ann Rueschemeyer et al. 288 citations

The default mode network supports cognition independent of immediate environment and higher-order conceptual representations. A novel paradigm manipulated perceptual information availability and representational complexity during decision-making. Brain regions including left and right angular gyri and left middle temporal gyrus responded when cognition combined stimulus independence with multi-modal information. These default mode network sites showed stronger response to demanding memory judgments than easier perceptual tasks, contradicting the view they support automatic cognition. These regions were at the extreme end of a macroscale gradient from sensorimotor to transmodal cortex, suggesting functional distance from sensory input enables conceptually rich cognitive states in absence of input.

Auditory Hallucinations and the Brain’s Resting-State Networks: Findings and Methodological Observations

Schizophrenia Bulletin June 8, 2016 Ben Alderson‐day, Kelly Diederen, Charles Fernyhough et al. 134 citations

Resting-state brain networks may help explain hallucinations across different sensory modalities and populations. This report from the International Consortium on Hallucination Research reviews evidence linking resting-state alterations to auditory hallucinations, finding connectivity differences in left-hemisphere auditory and language regions, plus atypical interactions of the default mode network with networks for cognitive control and salience. Similar patterns appear in visual hallucinations, suggesting both domain-general and modality-specific network changes. However, high methodological heterogeneity across studies limits direct comparisons. The authors offer recommendations for future research on resting-state connectivity and hallucinations.

The neural correlates of ongoing conscious thought

iScience February 2, 2021 Jonathan Smallwood, Adam Turnbull, Hao-ting Wang et al. 130 citations

The landscape of ongoing thought is heterogeneous and shaped by both personal traits and environmental context. Recent work shows that attention and control systems organize experience in response to changing demands, while the default mode network contributes not only to task-negative or episodic content but also to the vividness of experience in both task contexts and spontaneous self-generated states. Multiple neural systems reflect the landscape of ongoing thought, and it is important to distinguish processes that shape how experience unfolds from those that regulate it.

The psychological correlates of distinct neural states occurring during wakeful rest

Scientific Reports December 3, 2020 Theodoros Karapanagiotidis, Diego Vidaurre, Andrew J. Quinn et al. 82 citations

When people are not engaged in an explicit task, they experience a variety of self-generated thoughts, such as planning or reminiscing. Using machine learning to analyze brain activity from resting-state fMRI scans, researchers identified distinct neural states that recur over time. Two of these states predicted different patterns of thinking. One neural state, resembling activity seen during demanding tasks, was linked to problem-solving about the future. Another state, associated with less demanding conditions, was tied to intrusive thoughts about the past. These two states fell at opposite ends of a brain hierarchy related to cognitive demand. The findings show that tracking moment-to-moment changes in brain function can help classify self-generated mental states and that these states align with the brain's response to cognitive tasks.

Mindfulness-based therapy regulates brain connectivity in major depression

May 29, 2019 Michael Lifshitz, Matthew D. Sacchet, Julia M. Huntenburg et al. 1 citation

Major depressive disorder involves abnormal communication between large-scale brain networks. A randomized, active-controlled trial tested whether mindfulness-based therapy could alter resting-state functional connectivity in clinically depressed patients. A brief, clinically effective mindfulness intervention functionally decoupled top-down control regions from brain areas involved in sensory, affective, and attentional processing. These findings identify specific neural targets of mindfulness training, offering new insight into how this therapeutic approach works.