Biology subjects

Lewis-Peacock, J.

Publications and source records attributed to Lewis-Peacock, J..

3 recordsLinked to original sources

bioRxiv2025

Multivariate Neural Markers of Individual Differences in Thought Control Difficulties

Difficulties in controlling thought, including pathological rumination, worry, and intrusive thoughts, occur in a range of mental health disorders. Here we identify specific patterns of brain activity distributed within and across canonical brain networks that are associated with self-reported difficulties in controlling ones thoughts. These activity patterns were derived using multivariate pattern analysis on fMRI data recorded while participants engaged in one of four operations on an item in working memory: maintaining it, replacing it with another, specifically suppressing it, or clearing the mind of all thought. Individuals who reported greater difficulties exhibited brain activation patterns that were more variable and less differentiated across the four operations in frontoparietal and default mode networks, and showed less distinct patterns of connectivity within the default mode network. These activity profiles were absent during rest but serve as promising task-based neural markers, explaining over 30% of the variance in thought control difficulties.

neuroscience↗

bioRxiv2023

Neural Systems Underlying the Implementation of Working Memory Removal Operations

Recently multi-voxel pattern analysis has verified the removal of information from working memory (WM) via three distinct operations replacement, suppression, or clearing compared to information being maintained (Kim et al., 2020). Univariate analyses and classifier importance maps indicate that some brain regions commonly contribute to these operations. This study aimed to use multivariate approaches to determine whether, within these commonly activated brain regions, each of these operations is being represented in a similar or distinct manner. To do so, we used Leiden community detection to identify brain networks that are characterized by similar multi-voxel patterns of activity with regard to these WM operations. Four networks were identified. The Visual Network shows similar multi-voxel patterns for maintain and replace, which are highly dissimilar from suppress and clear, suggesting this network differentiates whether an item is held in WM or not. The Somatomotor Network shows distinct multi-voxel patterns for clear relative to the other operations, suggesting that this network diff in clearing information from WM. The Default Mode Network has distinct patterns for suppress and clear, also suggesting that clearing information from WM is distinct from suppressing it. The Frontoparietal Control Network displays distinct multi-voxel patterns for each of the four operations, suggesting that this network has high involvement in regulating the flow of information within WM. These results indicate that how information is removed from WM depends on distinct brain networks that each have a particular manner in which their co-activation patterns represent these operations. SIGNIFICANCE STATEMENTThe ability to actively remove, manipulate and maintain information in working memory (WM) is required for encoding of new information and for controlling thoughts. This study revealed that different brain networks show characteristic multi-voxel activity patterns across four distinct WM operations: maintenance of information, replacement of one item by another, suppression of a specific item, and clearing the mind of all thought. One network, the Frontoparietal Control Network, differentiates all four operations, suggesting it may play a critical role in the controlled removal of information from WM.

neuroscience↗

bioRxiv2018

Dissociating refreshing and elaboration by their neural signatures and their effects on memory in young and old adults

Maintenance of information in working memory (WM) is assumed to rely on refreshing and elaboration, but clear mechanistic descriptions of these cognitive processes are lacking, and it is unclear whether they are simply two labels for the same process. This fMRI study investigated the extent to which refreshing, elaboration, and repeating of items in WM are distinct neural processes with dissociable behavioral outcomes in WM and long-term memory (LTM). Multivariate pattern analyses of fMRI data revealed differentiable neural signatures for these processes, which we also replicated in an independent sample of older adults. In some cases, the degree of neural separation within an individual predicted their memory performance. Elaboration improved LTM, but not WM, and this benefit increased as its neural signature became more distinct from repetition. Refreshing had no impact on LTM, but did improve WM, although the neural discrimination of this process was not predictive of the degree of improvement. These results demonstrate that refreshing and elaboration are separate processes that differently contribute to memory performance.\n\nHighlightsO_LIRepeated reading, refreshing, and elaboration are differentiable in brain activation patterns in both young and older adults.\nC_LIO_LIElaboration selectively improved long-term memory for young adults, and the size of the benefit was related to the neural separability of elaboration from other processes.\nC_LIO_LIOlder adults implemented a sub-optimal form of elaboration, and this may be a factor contributing to age-related deficits in long-term memory.\nC_LI\n\nEthics statementThe study was approved by the ethical review board of the canton of Zurich (BASEC-No. 2017-00190) and all subjects gave informed written consent in accordance with the Declaration of Helsinki.\n\nData and code availability statementAll behavioral data and analysis scripts can be assessed on the Open Science Framework (osf.io/p2h8b/). The fMRI data that support the findings of this study are available on request from the corresponding author, LMB. The fMRI data are not publicly available due to restrictions of the Swiss Ethics Committees on research involving humans regarding data containing information that could compromise the privacy of research participants.

neuroscience↗