UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Efficiently searching through large tACS parameter spaces using closed-loop Bayesian optimization

Lorenz, R; Simmons, LE; Monti, RP; Arthur, JL; Limal, S; Laakso, I; Leech, R; (2019) Efficiently searching through large tACS parameter spaces using closed-loop Bayesian optimization. Brain Stimulation , 12 (6) pp. 1484-1489. 10.1016/j.brs.2019.07.003. Green open access

[thumbnail of 1-s2.0-S1935861X19302852-main.pdf]
Preview
Text
1-s2.0-S1935861X19302852-main.pdf - Published version

Download (1MB) | Preview

Abstract

Background: Selecting optimal stimulation parameters from numerous possibilities is a major obstacle for assessing the efficacy of non-invasive brain stimulation. Objective: We demonstrate that Bayesian optimization can rapidly search through large parameter spaces and identify subject-level stimulation parameters in real-time. Methods: To validate the method, Bayesian optimization was employed using participants’ binary judgements about the intensity of phosphenes elicited through tACS. Results: We demonstrate the efficiency of Bayesian optimization in identifying parameters that maximize phosphene intensity in a short timeframe (5 min for >190 possibilities). Our results replicate frequency-dependent effects across three montages and show phase-dependent effects of phosphene perception. Computational modelling explains that these phase effects result from constructive/ destructive interference of the current reaching the retinas. Simulation analyses demonstrate the method's versatility for complex response functions, even when accounting for noisy observations. Conclusion: Alongside subjective ratings, this method can be used to optimize tACS parameters based on behavioral and neural measures and has the potential to be used for tailoring stimulation protocols to individuals.

Type: Article
Title: Efficiently searching through large tACS parameter spaces using closed-loop Bayesian optimization
Open access status: An open access version is available from UCL Discovery
DOI: 10.1016/j.brs.2019.07.003
Publisher version: https://doi.org/10.1016/j.brs.2019.07.003
Language: English
Additional information: This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Keywords: Transcranial alternating current stimulation, Experimental design, Machine-learning, Bayesian optimization, Real-time, Phosphenes
UCL classification: UCL
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Gatsby Computational Neurosci Unit
URI: https://discovery.ucl.ac.uk/id/eprint/10082667
Downloads since deposit
34Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item