A new paper led by Luke Tait is published on Neuroimage.

We generalise the microstate methodology to be applicable to source-reconstructed electrophysiological data. Using simulations of a neural-mass network model, we first established the validity and robustness of the proposed method. Using MEG resting-state data, we uncovered ten microstates with distinct spatial distributions of cortical activation. Multivariate pattern analysis demonstrated that source-level microstates were associated with distinct functional connectivity patterns. We further demonstrated that the occurrence probability of MEG microstates were altered by auditory stimuli, exhibiting a hyperactivity of the microstate including the auditory cortex. Our results support the use of source-level microstates as a method for investigating brain dynamic activity and connectivity at the millisecond scale.

The paper is now available online.

Everyone has been busy in the last few weeks with various projects. We however managed to have a face-to-face get-together. The first is to welcome our new Research Fellow Sabina Baltruschat. Sabina will work on MRI/MEG decision-making projects.

We also say goodbye to Marinho. Marinho joined us in 2019 and has made substantial achievements in his work on the mathematical modelling of epileptic seizures with MEG and stereo-EEG data. Marinho will still collaborate closely on ongoing projects, and we wish Marinho all the best for his future adventures.

A new paper led by Ruoguang Si is published on Neuroimage. This meta-analysis study identified 35 fMRI/PET experiments using various free-choice paradigms, in which participants choose among options with identical values or outcomes.

An Activation Likelihood Estimate (ALE) meta-analysis showed that, compared with external instructions, intentional decisions consistently activate the medial and dorsolateral prefrontal cortex, the left insula and the inferior parietal lobule. We then categorized the studies into four different types according to their experimental designs: reactive motor intention, perceptual intention, inhibitory intention, and cognitive intention. We conducted conjunction and contrast meta-analyses to identify consistent and selective spatial convergence of brain activation within each specific category of intentional decision. Finally, we used meta-analytic decoding to probe cognitive processes underlying free choices. Our findings suggest that the neurocognitive process underlying intentional decision incorporates anatomically separated components subserving distinct cognitive and computational roles.

The paper is now available online.

A new paper led by Luke Tait is published on Human Brain mapping. This study systematically evaluated the performance of six commonly-used source reconstruction algorithms. Using human resting-state MEG, we compared the algorithms using quantitative metrics, including resolution properties of inverse solutions and explained variance in sensor-level data. Next, we proposed a data-driven approach to reduce the atlas from the Human Connectome Project’s multi-modal parcellation of the human cortex based on metrics such as MEG signal-to-noise-ratio and resting-state functional connectivity gradients. This procedure produced a reduced cortical atlas with 230 regions, optimized to match the spatial resolution and the rank of MEG data from the current generation of MEG scanners.

Our results show that there is no “one size fits all” algorithm, and make recommendations on the appropriate algorithms depending on the data and aimed analyses. Our comprehensive comparisons and recommendations can serve as a guide for choosing appropriate methodologies in future studies of resting-state MEG.

The paper is now available online.

Wojciech Zajkowski passed his viva last month. Big congratulations and we wish Wojciech all the best in his new reserach fellow position.

Thin month we welcome a new member Nikolay Petrov. Nikolay will work on our internet-based behavioural experiments.

Also, some lab members are finally able to catch up face-to-face after over 15 months of COVID restrictions.