Towards an Ontology of Ongoing Thought

Functional outcomes of ongoing thought show both costs and benefits. Yet, the reason for its heterogeneity remains unclear. The executive failure and representational accounts stemmed from different psychological research approaches to understand ongoing thought. The executive failure account examines why changes in ongoing thought happen, while the representational account seeks to explain how humans generate ongoing thought. The attentional system and the default mode network are the common neural processes of both theoretical accounts, but interacting in a contradicting manner. The two accounts can be seen as competing theories of ongoing thought. However, in the family resemblance view (Seli et al., 2018), the two theoretical accounts potentially serve as two component processes of one phenomenon. One possible solution to this conflict could be that under different global neural configurations, the two networks support different cognitive functions. The thesis sets out to present evidence supporting of the family resemblance view and to begin research on the ontology of the component processes in ongoing thought. Neural cognitive hierarchy is the potential explanation of the heterogeneity. The current thesis adopts sparse canonical correlation analysis to incorporate the neural and behavioural aspects of ongoing thought. The data suggests ongoing thought is a collective phenomenon with many types of experience driven by the connectivity patterns in the default mode network. Each type of experience associated with their unique functional outcomes and neural hierarchies at the whole-brain level. Cognitive flexibility and the balance of segregation and integration between the transmodal systems and the rest of the cortex determines the immersive details. The current findings suggested the importance of whole-brain neural hierarchies to ongoing thought. The confirmation of these trait level findings at a state level are necessary to gain more insights into the architecture of the component processes

Macro-scale patterns in functional connectivity associated with ongoing thought patterns and dispositional traits

Complex macro-scale patterns of brain activity that emerge during periods of wakeful rest provide insight into the organisation of neural function, how these differentiate individuals based on their traits, and the neural basis of different types of self-generated thoughts. Although brain activity during wakeful rest is valuable for understanding important features of human cognition, its unconstrained nature makes it difficult to disentangle neural features related to personality traits from those related to the thoughts occurring at rest. Our study builds on recent perspectives from work on ongoing conscious thought that highlight the interactions between three brain networks - ventral and dorsal attention networks, as well as the default mode network. We combined measures of personality with state-of-the-art indices of ongoing thoughts at rest and brain imaging analysis, and explored whether this ‘tri-partite’ view can provide a framework within which to understand the contribution of states and traits to observed patterns of neural activity at rest. To capture macro-scale relationships between different brain systems, we calculated cortical gradients to describe brain organisation in a low dimensional space. Our analysis established that for more introverted individuals, regions of the ventral attention network were functionally more aligned to regions of the somatomotor system and the default mode network. At the same time, a pattern of detailed self-generated thought was associated with a decoupling of regions of dorsal attention from regions in the default mode network. Our study, therefore, establishes interactions between attention systems and the default mode network are important influences on ongoing thought at rest and highlights the value of integrating contemporary perspectives on conscious experience when understanding patterns of brain activity at rest

The disentanglement of the neural and experiential complexity of self-generated thoughts : A users guide to combining experience sampling with neuroimaging data

Human cognition is not limited to the processing of events in the external environment, and the covert nature of certain aspects of the stream of consciousness (e.g. experiences such as mind-wandering) provides a methodological challenge. Although research has shown that we spend a substantial amount of time focused on thoughts and feelings that are intrinsically generated, evaluating such internal states, purely on psychological grounds can be restrictive. In this review of the different methods used to examine patterns of ongoing thought, we emphasise how the process of triangulation between neuroimaging techniques, with self-reported information, is important for the development of a more empirically grounded account of ongoing thought. Specifically, we show how imaging techniques have provided critical information regarding the presence of covert states and can help in the attempt to identify different aspects of experience

Reductions in task positive neural systems occur with the passage of time and are associated with changes in ongoing thought

Cognition is dynamic and involves both the maintenance of and transitions between neurocognitive states. While recent research has identified some of the neural systems involved in sustaining task states, it is less well understood how intrinsic influences on cognition emerge over time. The current study uses fMRI and Multi-Dimensional Experience Sampling (MDES) to chart how cognition changes over time from moments in time when external attention was established. We found that the passage of time was associated with brain regions associated with external attention decreasing in activity over time. Comparing this pattern of activity to defined functional hierarchies of brain organization, we found that it could be best understood as movement away from systems involved in task performance. Moments where the participants described their thoughts as off-task showed a significant similarity to the task-negative end of the same hierarchy. Finally, the greater the similarity of a participant's neural dynamics to this hierarchy the faster their rate of increasing off-task thought over time. These findings suggest topographical changes in neural processing that emerge over time and those seen during off-task thought can both be understood as a common shift away from neural motifs seen during complex task performance

Context independent reductions in external processing during self-generated episodic social cognition

Ongoing cognition supports behavioral flexibility by facilitating behavior in the moment, and through the consideration of future actions. These different modes of cognition are hypothesized to vary with the correlation between brain activity and external input, since evoked responses are reduced when cognition switches to topics unrelated to the current task. This study examined whether these reduced evoked responses change as a conse-quence of the task environment in which the experience emerges. We combined electro-encephalography (EEG) recording with multidimensional experience sampling (MDES) to assess the electrophysiological correlates of ongoing thought in task contexts which vary on their need to maintain continuous representations of task information for satisfactory performance. We focused on an event-related potential (ERP) known as the parietal P3 that had a greater amplitude in our tasks relying on greater external attention. A principal component analysis (PCA) of the MDES data revealed four patterns of ongoing thought: off-task episodic social cognition, deliberate on-task thought, imagery, and emotion. Partici-pants reported more off-task episodic social cognition and mental imagery under low external demands and more deliberate on-task thought under high external task demands. Importantly, the occurrence of off-task episodic social cognition was linked to similar re-ductions in the amplitude of the P3 regardless of external task. These data suggest the amplitude of the P3 may often be a general feature of external task-related content and suggest attentional decoupling from sensory inputs are necessary for certain types of perceptually-decoupled, self-generated thoughts.Peer reviewe

Distinct patterns of thought mediate the link between brain functional connectomes and well-being

Ongoing thought patterns constitute important aspects of both healthy and abnormal human cognition. However, the neural mechanisms behind these daily experiences and their contribution to well-being remain a matter of debate. Here, using resting-state fMRI and retrospective thought sampling in a large neurotypical cohort (n = 211), we identified two distinct patterns of thought, broadly describing the participants’ current concerns and future plans, that significantly explained variability in the individual functional connectomes. Consistent with the view that ongoing thoughts are an emergent property of multiple neural systems, network-based analysis highlighted the central importance of both unimodal and transmodal cortices in the generation of these experiences. Importantly, while state-dependent current concerns predicted better psychological health, mediating the effect of functional connectomes, trait-level future plans were related to better social health, yet with no mediatory influence. Collectively, we show that ongoing thoughts can influence the link between brain physiology and well-being

Making the Most of Opportunities to Learn What Works: A School District's Guide

This guide for district and school leaders shows how to recognize opportunities to embed randomized controlled trials (RCTs) into planned policies or programs. Opportunistic RCTs can generate strong evidence for informing education decisions -- with minimal added cost and disruption. The guide also outlines the key steps to conduct RCTs and responds to common questions and concerns about RCTs. Readers will find a real life example of how one district took advantage of an opportunity to learn whether a summer reading program worked