Stochastic resonance enhances the rate of evidence accumulation during combined brain stimulation and perceptual decision-making

Open access
Date
2018Type
- Journal Article
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Abstract
Perceptual decision-making relies on the gradual accumulation of noisy sensory evidence. It is often assumed that such decisions are degraded by adding noise to a stimulus, or to the neural systems involved in the decision making process itself. But it has been suggested that adding an optimal amount of noise can, under appropriate conditions, enhance the quality of subthreshold signals in nonlinear systems, a phenomenon known as stochastic resonance. Here we asked whether perceptual decisions made by human observers obey these stochastic resonance principles, by adding noise directly to the visual cortex using transcranial random noise stimulation (tRNS) while participants judged the direction of coherent motion in random-dot kinematograms presented at the fovea. We found that adding tRNS bilaterally to visual cortex enhanced decision-making when stimuli were just below perceptual threshold, but not when they were well below or above threshold. We modelled the data under a drift diffusion framework, and showed that bilateral tRNS selectively increased the drift rate parameter, which indexes the rate of evidence accumulation. Our study is the first to provide causal evidence that perceptual decision-making is susceptible to a stochastic resonance effect induced by tRNS, and to show that this effect arises from selective enhancement of the rate of evidence accumulation for sub-threshold sensory events. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000281978Publication status
publishedExternal links
Journal / series
PLoS Computational BiologyVolume
Pages / Article No.
Publisher
Public Library of ScienceOrganisational unit
03963 - Wenderoth, Nicole / Wenderoth, Nicole
Funding
149561 - Driving the human motor system by somatosensory input (SNF)
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Citations
Cited null times in
Web of Science
Cited 16 times in
Scopus
ETH Bibliography
yes
Altmetrics