+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Transcranial alternating current stimulation: a review of the underlying mechanisms and modulation of cognitive processes


      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          Brain oscillations of different frequencies have been associated with a variety of cognitive functions. Convincing evidence supporting those associations has been provided by studies using intracranial stimulation, pharmacological interventions and lesion studies. The emergence of novel non-invasive brain stimulation techniques like repetitive transcranial magnetic stimulation (rTMS) and transcranial alternating current stimulation (tACS) now allows to modulate brain oscillations directly. Particularly, tACS offers the unique opportunity to causally link brain oscillations of a specific frequency range to cognitive processes, because it uses sinusoidal currents that are bound to one frequency only. Using tACS allows to modulate brain oscillations and in turn to influence cognitive processes, thereby demonstrating the causal link between the two. Here, we review findings about the physiological mechanism of tACS and studies that have used tACS to modulate basic motor and sensory processes as well as higher cognitive processes like memory, ambiguous perception, and decision making.

          Related collections

          Most cited references51

          • Record: found
          • Abstract: found
          • Article: not found

          Simple model of spiking neurons.

          A model is presented that reproduces spiking and bursting behavior of known types of cortical neurons. The model combines the biologically plausibility of Hodgkin-Huxley-type dynamics and the computational efficiency of integrate-and-fire neurons. Using this model, one can simulate tens of thousands of spiking cortical neurons in real time (1 ms resolution) using a desktop PC.
            • Record: found
            • Abstract: found
            • Article: not found

            Dynamic predictions: oscillations and synchrony in top-down processing.

            Classical theories of sensory processing view the brain as a passive, stimulus-driven device. By contrast, more recent approaches emphasize the constructive nature of perception, viewing it as an active and highly selective process. Indeed, there is ample evidence that the processing of stimuli is controlled by top-down influences that strongly shape the intrinsic dynamics of thalamocortical networks and constantly create predictions about forthcoming sensory events. We discuss recent experiments indicating that such predictions might be embodied in the temporal structure of both stimulus-evoked and ongoing activity, and that synchronous oscillations are particularly important in this process. Coherence among subthreshold membrane potential fluctuations could be exploited to express selective functional relationships during states of expectancy or attention, and these dynamic patterns could allow the grouping and selection of distributed neuronal responses for further processing.
              • Record: found
              • Abstract: found
              • Article: not found

              Neural synchrony in brain disorders: relevance for cognitive dysfunctions and pathophysiology.

              Following the discovery of context-dependent synchronization of oscillatory neuronal responses in the visual system, novel methods of time series analysis have been developed for the examination of task- and performance-related oscillatory activity and its synchronization. Studies employing these advanced techniques revealed that synchronization of oscillatory responses in the beta- and gamma-band is involved in a variety of cognitive functions, such as perceptual grouping, attention-dependent stimulus selection, routing of signals across distributed cortical networks, sensory-motor integration, working memory, and perceptual awareness. Here, we review evidence that certain brain disorders, such as schizophrenia, epilepsy, autism, Alzheimer's disease, and Parkinson's are associated with abnormal neural synchronization. The data suggest close correlations between abnormalities in neuronal synchronization and cognitive dysfunctions, emphasizing the importance of temporal coordination. Thus, focused search for abnormalities in temporal patterning may be of considerable clinical relevance.

                Author and article information

                Front Hum Neurosci
                Front Hum Neurosci
                Front. Hum. Neurosci.
                Frontiers in Human Neuroscience
                Frontiers Media S.A.
                14 June 2013
                : 7
                : 279
                [1] 1Experimental Psychology Lab, Center of excellence Hearing4all, Department for Psychology, Faculty for Medicine and Health Sciences, Carl von Ossietzky Universität, Ammerländer Heerstr Oldenburg, Germany
                [2] 2Research Center Neurosensory Science, Carl von Ossietzky Universität Oldenburg, Germany
                Author notes

                Edited by: Risto J. Ilmoniemi, Aalto University, Finland

                Reviewed by: Jack Van Honk, Utrecht University, Netherlands; Paul Sauseng, University of Surrey, UK

                *Correspondence: Christoph S. Herrmann, Department of Experimental Psychology, Carl von Ossietzky Universität, Ammerländer Heerstr. 114-118, D-26129 Oldenburg, Germany e-mail: christoph.herrmann@ 123456uni-oldenburg.de
                Copyright © 2013 Herrmann, Rach, Neuling and Strüber.

                This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.

                : 31 January 2013
                : 28 May 2013
                Page count
                Figures: 7, Tables: 0, Equations: 0, References: 74, Pages: 13, Words: 10244
                Review Article

                alpha,eeg,electroencephalogram,gamma,oscillations,transcranial direct current stimulation,transcranial alternating current stimulation,transcranial magnetic stimulation


                Comment on this article