Suboptimal Engagement of High-Level Cortical Regions Predicts Random-Noise-Related Gains in Sustained Attention

Psychol Sci. 2019 Sep;30(9):1318-1332. doi: 10.1177/0956797619856658. Epub 2019 Jul 19.


Interindividual variability in outcomes across individuals poses great challenges for the application of noninvasive brain stimulation in psychological research. Here, we examined how the effects of high-frequency transcranial random-noise stimulation (tRNS) on sustained attention varied as a function of a well-studied electrocortical marker: spontaneous theta:beta ratio. Seventy-two participants received sham, 1-mA, and 2-mA tRNS in a double-blind, crossover manner while they performed a sustained-attention task. Receiving 1-mA tRNS was associated with improved sustained attention, whereas the effect of 2-mA tRNS was similar to the effect of sham tRNS. Furthermore, individuals' baseline theta:beta ratio moderated the effects of 1-mA tRNS and provided explanatory power beyond baseline behavioral performance. The tRNS-related effects on sustained attention were also accompanied by reductions in theta:beta ratio. These findings impart novel insights into mechanisms underlying tRNS effects and emphasize how designing studies that link variability in cognitive outcomes to variability in neurophysiology can improve inferential power in neurocognitive research.

Keywords: electrophysiology; interindividual variability; noninvasive brain stimulation; theta:beta ratio.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Attention / physiology*
  • Beta Rhythm / physiology*
  • Contrast Sensitivity / physiology
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Pattern Recognition, Visual / physiology
  • Prefrontal Cortex / physiology*
  • Psychomotor Performance / physiology*
  • Theta Rhythm / physiology*
  • Transcranial Direct Current Stimulation*
  • Young Adult