Transcranial Alternating Current Stimulation Enhances Individual Alpha Activity in Human EEG

By Tino Zaehle, Stefan Rach, Christoph S. Herrmann. PLoS ONE, 2010

784 citations recorded by the source corpus.

Non-invasive electrical stimulation of the human cortex by means of transcranial direct current stimulation (tDCS) has been instrumental in a number of important discoveries in the field of human cortical function and has become a well-established method for evaluating brain function in healthy human participants. Recently, transcranial alternating current stimulation (tACS) has been introduced to directly modulate the ongoing rhythmic brain activity by the application of oscillatory currents on the human scalp. Until now the efficiency of tACS in modulating rhythmic brain activity has been indicated only by inference from perceptual and behavioural consequences of electrical stimulation. No direct electrophysiological evidence of tACS has been reported. We delivered tACS over the occipital cortex of 10 healthy participants to entrain the neuronal oscillatory activity in their individual alpha frequency range and compared results with those from a separate group of participants receiving sham stimulation. The tACS but not the sham stimulation elevated the endogenous alpha power in parieto-central electrodes of the electroencephalogram. Additionally, in a network of spiking neurons, we simulated how tACS can be affected even after the end of stimulation. The results show that spike-timing-dependent plasticity (STDP) selectively modulates synapses depending on the resonance frequencies of the neural circuits that they belong to. Thus, tACS influences STDP which in turn results in aftereffects upon neural activity. The present findings are the first direct electrophysiological evidence of an interaction of tACS and ongoing oscillatory activity in the human cortex. The data demonstrate the ability of tACS to specifically modulate oscillatory brain activity and show its potential both at fostering knowledge on the functional significance of brain oscillations and for therapeutic application.

Subfields: Cognitive Neuroscience, Neurology

View Paper: https://www.semanticscholar.org/paper/0ff73511e54f6444d8c989bf213dfffbc58c655f

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Cognitive Neuroscience

In Neurology

Citations in the corpus

Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology: Current approaches and future perspectives (2016, positive): “Also the after-effects of 10 Hz TACS on subsequent alpha power (Neuling et al., 2013; Zaehle et al., 2010) may benefit from concurrent adjustment of stimulation intensity to overcome decreased efficacy of the stimulation during periods of high spontaneous alpha power (Neuling et al., 2013).”
Entrainment of brain oscillations by transcranial alternating current stimulation. (2014, neutral): “So far, electrophysiological evidence in humans was limited to EEG recordings after stimulation [18, 19].”
Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines (2017, background): “…(provided detailed attention to potential artifact; (Noury et al. , 2016))to monitor the effects and efficacy of tACS on brain activity (Antal et al. , 2008a, Zaehle et al. , 2010) similarly to tDCS (Cunillera et al. , 2016, Faria et al., 2012, Luft et al. , 2014, Mancini et al. , 2015).”
A technical guide to tDCS, and related non-invasive brain stimulation tools (2015, background): “It is possible to enhance the amplitude of an electroencephalography (EEG) oscillation by applying tACS at the frequency of that oscillation (Zaehle et al., 2010).”
Transcranial alternating current stimulation: a review of the underlying mechanisms and modulation of cognitive processes (2013, methodology): “In order to simulate also the after-effects of their EEG experiment, Zaehle et al. (2010) used a neural network composed of Izhikevich neurons.”
Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields (2013, neutral): “…and Paulus, 2013; Dayan et al., 2013; Fröhlich and McCormick, 2010; Herrmann et al., 2013; Merlet et al., 2013; Paulus, 2011; Ruffini et al., 2013; Zaehle et al., 2010) and devices such as StarStim already allow for the simultaneous multisite stimulation of different cortical regions with…”
Targeting neural oscillations with transcranial alternating current stimulation (2021, background): “Alternatively, stimulation can be delivered at the peak frequency of the individual (Reinhart and Nguyen, 2019; Zaehle et al., 2010; Vossen et al., 2015; Stecher and Herrmann, 2018) (Fig.”
Alpha oscillatory activity is causally linked to working memory retention (2023, background): “, IAF ± 2 Hz) that we selected was consistent with previous alpha-tACS studies [31,68,69].”
After-effects of parieto-occipital gamma transcranial alternating current stimulation on behavioral performance and neural activity in visuo-spatial attention task (2026, unknown): “Mechanistically, offline effects may reflect stimulation-induced plastic changes rather than transient entrainment (Zaehle et al. (2010); Vossen et al. (2015)), and may also depend on endogenous network state (Schmidt et al. (2014); Krause et al. (2022)).”