Biology subjects

Leto, C.

Publications and source records attributed to Leto, C..

2 recordsLinked to original sources

bioRxiv2025

EPICURUS: E-field-based spatial filtering procedure for an accurate estimation of local EEG activity evoked by Transcranial Magnetic Stimulation

BackgroundThe concurrent use of Transcranial magnetic stimulation and electroencephalography (TMS-EEG) is increasingly integrated into research and clinical protocols. However, a reliable isolation of EEG responses that are locally evoked by TMS at the targeted cortical sites independent from contaminating sources, remains challenging. MethodsHere we introduce EPICURUS, a novel spatial filtering approach for TMS-EEG that uses individualized MRI-based simulations of the TMS-induced electric field (E-field) to define the spatial extent of locally evoked activity. This method guides the reconstruction of EEG signals originating from the direct stimulation site while minimizing crosstalk from distant, non-targeted sources. ResultsIn synthetic simulations and a human TMS-EEG dataset, EPICURUS preserved early-latency TMS-evoked local activity while substantially attenuating later components, consistent with suppression of non-local activity. ConclusionBy leveraging the spatial precision of individualized E-field modeling, EPICURUS may enhance the specificity of EEG signal reconstruction, offering a promising tool for improving the spatiotemporal resolution of local early and late cortical local responses directly elicited by TMS.

neuroscience↗

bioRxiv2022

Attention Samples Items in Visual Working Memory Rhythmically

Attention allows us to selectively enhance the processing of specific locations or features in our external environment while simultaneously filtering out momentarily irrelevant information. It is currently hypothesized that this is achieved through the boosting of relevant sensory signals which biases the competition between competing neural representations. Recent neurophysiological and behavioral studies have revealed that attention is a fundamentally rhythmic process, tightly linked to neural oscillations in fronto-parietal networks. Instead of continuously highlighting a single object or location, attention rhythmically alternates between multiple relevant representations at a frequency of 3 - 6 Hz. However attention can not only be directed towards the external world but also towards internal visual working memory (VWM) representations, e.g. when selecting one of several search templates to find corresponding objects in the external world. Two recent studies have revealed that objects in VWM are attended in a similarly rhythmic fashion as perceived objects. We add to the current literature by showing that retro-cues towards multi-feature gratings in VWM initiate a similar theta-rhythmic competition, modulating reaction times in an anti-phasic manner. Our findings add to the converging body of evidence that external and internal visual representations are accessed by highly similar, rhythmic attentional mechanisms.

neuroscience↗