Biology subjects

Phylactou, P.

Publications and source records attributed to Phylactou, P..

4 recordsLinked to original sources

bioRxiv2026

Development and Validation of the Transcranial Magnetic Stimulation Reporting Assessment Tool(TMS-RAT)

HighlightsO_LIWe introduce the TMS-RAT, a reporting (assessment) tool for TMS studies C_LIO_LIDeveloped within a community-informed, iterative process rating 333 TMS studies C_LIO_LIEmpirically evaluated for usability, inter-rater, and test-retest reliability C_LIO_LIA validated subset enables reliable retrospective assessment of reporting C_LIO_LIThe modular structure enables use across a wide range of TMS study designs C_LI BackgroundA standardised tool for comprehensive reporting can improve transparency, support consistent documentation, and enable comparison across transcranial magnetic stimulation (TMS) studies. The most used reporting checklist lacks clear definitions of full reporting and was not initially evaluated for usability or inter-rater reliability. A scoping review of studies using this checklist shows that its items are reported only 50% of the time, suggesting that method descriptions are often incomplete. MethodsWe developed the TMS Reporting Assessment Tool (TMS-RAT), a comprehensive reporting framework that provides clear definitions and examples for its items, covering a wide range of TMS protocols. We tested the usability and reliability of the TMS-RAT by rating all studies published between 1991 and 2025 using afferent conditioning (n = 333), a protocol encompassing many reporting categories identified during tool development. Seventeen independent raters contributed across three development phases, a validation phase, and a retest phase, with naive raters introduced in each phase. Iterative refinements of the tool were informed by inter-rater reliability, qualitative rater feedback, and consultation with external TMS experts. ResultsWe present two versions of the tool: the 72-item TMS-RAT v1.0, designed to guide comprehensive reporting, and the TMS-RAT v1.1, a subset of 50 items with the highest inter-rater (overall AC1 = 0.78, range = [0.60-0.99]) and test-retest reliability (overall AC1 = 0.82, range = [0.65-1.0]), intended for retrospective evaluation of reporting in systematic reviews, meta-analyses. ConclusionThe TMS-RAT is a comprehensive, reliable tool that seeks to improve transparency and reproducibility in TMS research.

neuroscience↗

bioRxiv2025

Transcranial magnetic stimulation induced pupil dilations can serve as a cortical excitability measure

The application of non-invasive brain stimulation (NIBS) often relies on proxy estimates of cortical excitability (CE), such as the resting motor threshold (rMT), measured through transcranial magnetic stimulation (TMS). However, estimating the rMT is not always possible, as it requires an intact corticospinal pathway for neural signals to travel from the cortex to the periphery. To broaden the application of NIBS there is a need for additional CE measures. In three experiments combining TMS, transcranial direct current stimulation (tDCS), and eye-tracking, we measured TMS-induced pupil dilations as a potential CE proxy. We present Bayesian evidence (Experiment 1: BF > 9; Experiment 2: BF > 46; Experiment 3: BFs > 6) that TMS-induced pupil dilations serve as an objective CE proxy, with larger pupil size reflecting higher CE. We also show that these effects are not due to auditory, muscle, or sensory confounds. The introduction of this novel measure paves the way for a deeper understanding of CE by enabling objective NIBS measures beyond the motor cortex. Moving away from the reliance on the motor cortex would allow NIBS research and therapy to become more inclusive, allowing access to populations that are affected by damage along the corticospinal pathway.

neuroscience↗

bioRxiv2024

The human claustrum activates across multiple cognitive tasks

Cognitive control, the ability to manage information during purposeful actions, is crucial for everyday functioning and can become impaired in a variety of neuropsychiatric disorders. The claustrum, a subcortical brain structure, has recently been implicated in functional mechanisms underlying cognitive control. A current theory on the claustrums function, the Network Instantiation in Cognitive Control (NICC) model, proposes that the claustrum acts as a cortical network hub synchronizing distant parts of the brain to optimize task performance across cognitive domains. Testing this in this study, we examined the claustrum signal within a dataset (n = 55) that includes functional MRI (fMRI) of healthy participants engaged in four well-established cognitive tasks: the Stroop task, AX-continuous performance task (AX-CPT), cued task-switching, and Sternberg working memory task. Bilateral claustrum activation was observed during certain conditions and trial phases of all four tasks, particularly during active use of cognitive control, and coinciding with task-positive cortical network activations. These findings provide further support for the NICC model of claustrum function, demonstrating claustrum activation across multiple cognitive tasks, and potentially paving the way for new insights into how cognitive processes can become compromised in neuropsychiatric disorders.

neuroscience↗

bioRxiv2023

Phosphene and Motor Transcranial Magnetic Stimulation Thresholds Are Correlated: A Meta-Analytic Investigation

Transcranial magnetic stimulation (TMS) is commonly delivered at an intensity defined by the resting motor threshold (rMT), which is thought to represent cortical excitability, even if the TMS target area falls outside of the motor cortex. This approach rests on the assumption that cortical excitability, as measured through the motor cortex, represents a global measure of excitability. Another common approach to measure cortical excitability relies on the phosphene threshold (PT), measured through the visual cortex of the brain. However, it remains unclear whether either estimate can serve as a singular measure of global cortical excitability. If PT and rMT indeed reflect global cortical excitability, they should be correlated. To test this, we systematically identified previous studies that measured PT and rMT to calculate an overall correlation between the two estimates. Our results, based on 16 effect sizes from eight studies, indicated that PT and rMT are correlated ({rho} = .4), and thus one measure could potentially serve as a global cortical excitability measure. Three exploratory meta-analyses revealed that the strength of the correlation is affected by different methodologies, and that PT intensities are higher than rMT. Evidence for a PT-rMT correlation remained robust across all analyses. Further research is necessary for an in-depth understanding of how cortical excitability is reflected through TMS.

neuroscience↗