Nature Communications
August 23, 2019
Adam Turnbull, Hao-ting Wang, Charlotte Murphy et al.
197 citations
When a task is undemanding, people often let their minds wander to personally relevant thoughts. The dorsolateral prefrontal cortex (DLPFC), a brain region known for maintaining goal representations, also helps prioritize off-task thinking. Neural activity in the DLPFC was high both when people were on-task under demanding conditions and off-task during a non-demanding task. Individuals who increased off-task thought when external demands decreased showed weaker correlation between neural signals linked to external tasks and lateral default mode network regions within the DLPFC, and had less cortical grey matter in regions sensitive to those external signals. The findings suggest that humans use the DLPFC to align cognition with personal goals when environmental demands drop, prioritizing daydreaming.
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.
Neuroimage
June 22, 2020
Brontë Mckeown, Will Strawson, Hao-ting Wang et al.
102 citations
People whose brain connectivity patterns make the sensorimotor system most distinct from the visual system are more likely to report thoughts about solving problems or goals and less likely to report thoughts about the past. This finding comes from a study where participants underwent resting-state fMRI and then completed a questionnaire about their thoughts during the scan. A non-linear dimension reduction algorithm identified components explaining the greatest variance in whole-brain connectivity patterns. The results suggest that unique patterns of experience are linked to distinct neurocognitive profiles, with unimodal systems playing an important role.
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.
Andrew J. Anderson, Adam Turnbull, Feng V. Lin
preprint
The medial temporal subsystem of the default mode network (MT-DMN) encodes visual details of imagined autobiographical scenes. Fifty participants imagined personal experiences from generic prompts while undergoing fMRI. Using Stable Diffusion to create personalized images from participants' own descriptions, researchers found that MT-DMN activity patterns matched the representational structure of those images, even after accounting for semantic content. This effect was not seen in other brain networks or during reading without imagination, identifying the MT-DMN as a key area for reconstructing visual experiences from memory.