tDCS Modulates Visual Gamma Oscillations and Basal Alpha Activity in Occipital Cortices: Evidence from MEG
| Autor: | Timothy J. McDermott, Elizabeth Heinrichs-Graham, Mackenzie S. Mills, Tony W. Wilson, Nathan M. Coolidge |
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| Rok vydání: | 2017 |
| Předmět: |
Adult
Male Time Factors Cognitive Neuroscience Alpha (ethology) Stimulation Transcranial Direct Current Stimulation computer.software_genre Brain mapping Functional Laterality 050105 experimental psychology Young Adult 03 medical and health sciences Cellular and Molecular Neuroscience Basal (phylogenetics) 0302 clinical medicine Voxel medicine Gamma Rhythm Humans 0501 psychology and cognitive sciences Prefrontal cortex Brain Mapping medicine.diagnostic_test business.industry 05 social sciences Magnetoencephalography Original Articles Human brain Magnetic Resonance Imaging Alpha Rhythm medicine.anatomical_structure Female Occipital Lobe business computer Neuroscience Photic Stimulation 030217 neurology & neurosurgery |
| Zdroj: | Cerebral Cortex. 28:1597-1609 |
| ISSN: | 1460-2199 1047-3211 |
| DOI: | 10.1093/cercor/bhx055 |
| Popis: | Transcranial direct-current stimulation (tDCS) is now a widely used method for modulating the human brain, but the resulting physiological effects are not understood. Recent studies have combined magnetoencephalography (MEG) with simultaneous tDCS to evaluate online changes in occipital alpha and gamma oscillations, but no study to date has quantified the offline (i.e., after tDCS) alterations in these responses. Thirty-five healthy adults received active or sham anodal tDCS to the occipital cortices, and then completed a visual stimulation paradigm during MEG that is known to elicit robust gamma and alpha oscillations. The resulting MEG data were imaged and peak voxel time series were extracted to evaluate tDCS effects. We found that tDCS to the occipital increased the amplitude of local gamma oscillations, and basal alpha levels during the baseline. tDCS was also associated with network-level effects, including increased gamma oscillations in the prefrontal cortex, parietal, and other visual attention regions. Finally, although tDCS did not modulate peak gamma frequency, this variable was inversely correlated with gamma amplitude, which is consistent with a GABA-gamma link. In conclusion, tDCS alters gamma oscillations and basal alpha levels. The net offline effects on gamma activity are consistent with the view that anodal tDCS decreases local GABA. |
| Databáze: | OpenAIRE |
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