Parietal alpha stimulation causally enhances attentional information coding in evoked and oscillatory activity

Runhao Lu; Elizabeth Michael; Catriona L Scrivener; Jade B Jackson; John Duncan; Alexandra Woolgar

doi:10.1016/j.brs.2025.01.003

Parietal alpha stimulation causally enhances attentional information coding in evoked and oscillatory activity

Brain Stimul. 2025 Jan 6:S1935-861X(25)00005-1. doi: 10.1016/j.brs.2025.01.003. Online ahead of print.

Authors

Runhao Lu¹, Elizabeth Michael², Catriona L Scrivener³, Jade B Jackson², John Duncan², Alexandra Woolgar²

Affiliations

¹ MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK. Electronic address: Runhao.Lu@mrc-cbu.cam.ac.uk.
² MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
³ MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK; School of Philosophy, Psychology and Language Sciences, University of Edinburgh, Edinburgh, UK.

PMID: 39778653
DOI: 10.1016/j.brs.2025.01.003

Abstract

Background: Selective attention is a fundamental cognitive mechanism that allows people to prioritise task-relevant information while ignoring irrelevant information. Previous research has suggested key roles of parietal event-related potentials (ERPs) and alpha oscillatory responses in attention tasks. However, the informational content of these signals is less clear, and their causal effects on the coding of multiple task elements are yet unresolved.

Objective: To test the causal roles of alpha oscillations and ERPs in coding different types of attentional information (where to attend, what to attend to, and visual stimulus).

Methods: We first used EEG to examine the temporal dynamics of alpha oscillations and ERPs in coding attentional information. Then, we applied rhythmic-TMS (rh-TMS) at individual alpha frequency over the right intraparietal sulcus (IPS), while concurrently measuring EEG, to causally manipulate parietal alpha power and ERPs and investigate their roles in coding multiple task features in a selective attention task.

Results: EEG-only data suggested that ERPs coded all three types of task-relevant information with distinct temporal dynamics, while alpha oscillations carried information regarding both where to attend and what to attend to. TMS-EEG results indicated that, compared to arrhythmic-TMS, alpha rh-TMS increased alpha power and inter-trial phase coherence and yielded more negative posterior-contralateral ERPs. Moreover, alpha rh-TMS specifically and causally improved the multivariate decoding of the information about where to attend (but not what to attend to or feature information) during task performance, with decoding improvements predicting changes in behavioural performance.

Conclusions: These findings illuminate the dynamics with which the complementary aspects of a selective attention task are encoded in evoked and oscillatory brain activity. Moreover, they reveal a specific and causal role of IPS-controlled evoked and oscillatory activity in carrying behaviour-driving information exclusively about where to focus attention.