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P202 Outlasting effect of transcranial alternating current stimulation (tACS) on individual alpha power decays within 90 min after stimulation
Abstracts / Clinical Neurophysiology 128 (2017) e1–e163
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to visual cortex using tRNS (p = 0.02). Our results show that tRNS can be used to modulate the dynamics of cortical processing.
emphasizes the importance of a carefully chosen definition of the aftereffect and its reference (baseline or sham condition).
doi:10.1016/j.clinph.2016.10.320
References
P202 Outlasting effect of transcranial alternating current stimulation (tACS) on individual alpha power decays within 90 min after stimulation—F.H. Kasten a,*, J. Dowsett a,b, C.S. Herrmann a,c (a Carl von Ossietzky University, Experimental Psychology Lab, Department of Psychology, Oldenburg, Germany , b LMU, Center for Vertigo and Balance Disorders, Klinikum Grosshadern, Munich, Germany, c Carl von Ossietzky University, Research Center Neurosensory Science, Oldenburg, Germany) ⇑
Herrmann CS, Rach S, Neuling T, Strüber D. Transcranial alternating current stimulation: a review of the underlying mechanisms and modulation of cognitive processes. Front. Hum. Neurosci. 2013;7:1–13. doi:10.3389/fnhum.2013.00279. Neuling T, Rach S, Herrmann CS. Orchestrating neuronal networks: sustained aftereffects of transcranial alternating current stimulation depend upon brain states. Front. Hum. Neurosci. 2013;7:161. doi:10.3389/fnhum.2013.00161. Veniero D, Vossen A, Gross J, Thut G. Lasting EEG/MEG aftereffects of rhythmic transcranial brain stimulation: level of control over oscillatory network activity. Front. Cell Neurosci. 2015;9:477. doi:10.3389/fncel.2015.00477. doi:10.1016/j.clinph.2016.10.321
Corresponding author.
Introduction: Transcranial alternating current stimulation (tACS) has been shown to modulate spontaneous brain activity in a frequency specific manner (Herrmann et al., 2013). Numerous studies reported outlasting effects of tACS for different frequencies and stimulation protocols which commonly exceeded the duration of the experiment (Veniero et al., 2015). In the alpha band the effect has been shown to last for at least 30 min (Neuling et al., 2013). However, the further development and total duration of the aftereffect remain unclear. Objectives: The present study aimed to determine total duration and development of the tACS aftereffect beyond the previously reported 30 min. Materials & methods: Seventeen subjects received either 20 min of tACS or sham stimulation at their individual alpha frequency (IAF) using a Cz-Oz montage. EEG was measured during 3 min before and 90 min after tACS, while participants performed a visual vigilance task. Results: IAF band power (IAF ± 2 Hz) was increased in the verum group compared to baseline and sham for 70–80 min after stimulation. While alpha power in the verum group did not return to baseline, the group difference between verum and sham decayed due to an alpha power increase in the sham group. Conclusion: The current findings replicated previous observations of an aftereffect of tACS and for the first time demonstrated an upper limit for the duration of this aftereffect when compared to sham. Furthermore, the overall alpha rise over time for both groups
Figure 1.
P203 Is more better? A protocol to investigate the (neural) effects of repeated vs. single tACS in healthy and pathological ageing— L. Müller-Ehrenberg a,*, F. Verhey a, A. Sack b, H. Jacobs a,b (a Maastricht University, Faculty of Health Medicine and Life Sciences, School for Mental Health and Neuroscience (MHeNS), Alzheimer Centrum Limburg, Maastricht, Netherlands, b Maastricht University, Faculty of Psychology and Neuroscience, Cognitive Neuroscience, Maastricht, Netherlands) ⇑
Corresponding author.
Introduction: Healthy and pathological ageing, such as Alzheimer’s disease (AD), both co-occur with disruptions of neuronal activity in memory networks. A prodromal phase of AD is mild cognitive impairment (MCI). Transcranial current stimulation (tCS) has previously been implemented in various settings, showing to have beneficial influences on network connectivity. The recollection and hippocampal networks are vulnerable to AD-related pathology. Targeting these networks with tCS in an early phase may be a valid disease-delaying approach. The hippocampus cannot be stimulated directly, but is closely connected with the angular gyrus. By stimulating the angular gyrus during memory performance makes the recollection network more susceptible and therefore, we hypothesize that indirect effects might be detected in the hippocampus. Further, we will investigate the neural and cognitive effects of single vs multiple sessions. Knowledge about the (long-term)
e113
to visual cortex using tRNS (p = 0.02). Our results show that tRNS can be used to modulate the dynamics of cortical processing.
emphasizes the importance of a carefully chosen definition of the aftereffect and its reference (baseline or sham condition).
doi:10.1016/j.clinph.2016.10.320
References
P202 Outlasting effect of transcranial alternating current stimulation (tACS) on individual alpha power decays within 90 min after stimulation—F.H. Kasten a,*, J. Dowsett a,b, C.S. Herrmann a,c (a Carl von Ossietzky University, Experimental Psychology Lab, Department of Psychology, Oldenburg, Germany , b LMU, Center for Vertigo and Balance Disorders, Klinikum Grosshadern, Munich, Germany, c Carl von Ossietzky University, Research Center Neurosensory Science, Oldenburg, Germany) ⇑
Herrmann CS, Rach S, Neuling T, Strüber D. Transcranial alternating current stimulation: a review of the underlying mechanisms and modulation of cognitive processes. Front. Hum. Neurosci. 2013;7:1–13. doi:10.3389/fnhum.2013.00279. Neuling T, Rach S, Herrmann CS. Orchestrating neuronal networks: sustained aftereffects of transcranial alternating current stimulation depend upon brain states. Front. Hum. Neurosci. 2013;7:161. doi:10.3389/fnhum.2013.00161. Veniero D, Vossen A, Gross J, Thut G. Lasting EEG/MEG aftereffects of rhythmic transcranial brain stimulation: level of control over oscillatory network activity. Front. Cell Neurosci. 2015;9:477. doi:10.3389/fncel.2015.00477. doi:10.1016/j.clinph.2016.10.321
Corresponding author.
Introduction: Transcranial alternating current stimulation (tACS) has been shown to modulate spontaneous brain activity in a frequency specific manner (Herrmann et al., 2013). Numerous studies reported outlasting effects of tACS for different frequencies and stimulation protocols which commonly exceeded the duration of the experiment (Veniero et al., 2015). In the alpha band the effect has been shown to last for at least 30 min (Neuling et al., 2013). However, the further development and total duration of the aftereffect remain unclear. Objectives: The present study aimed to determine total duration and development of the tACS aftereffect beyond the previously reported 30 min. Materials & methods: Seventeen subjects received either 20 min of tACS or sham stimulation at their individual alpha frequency (IAF) using a Cz-Oz montage. EEG was measured during 3 min before and 90 min after tACS, while participants performed a visual vigilance task. Results: IAF band power (IAF ± 2 Hz) was increased in the verum group compared to baseline and sham for 70–80 min after stimulation. While alpha power in the verum group did not return to baseline, the group difference between verum and sham decayed due to an alpha power increase in the sham group. Conclusion: The current findings replicated previous observations of an aftereffect of tACS and for the first time demonstrated an upper limit for the duration of this aftereffect when compared to sham. Furthermore, the overall alpha rise over time for both groups
Figure 1.
P203 Is more better? A protocol to investigate the (neural) effects of repeated vs. single tACS in healthy and pathological ageing— L. Müller-Ehrenberg a,*, F. Verhey a, A. Sack b, H. Jacobs a,b (a Maastricht University, Faculty of Health Medicine and Life Sciences, School for Mental Health and Neuroscience (MHeNS), Alzheimer Centrum Limburg, Maastricht, Netherlands, b Maastricht University, Faculty of Psychology and Neuroscience, Cognitive Neuroscience, Maastricht, Netherlands) ⇑
Corresponding author.
Introduction: Healthy and pathological ageing, such as Alzheimer’s disease (AD), both co-occur with disruptions of neuronal activity in memory networks. A prodromal phase of AD is mild cognitive impairment (MCI). Transcranial current stimulation (tCS) has previously been implemented in various settings, showing to have beneficial influences on network connectivity. The recollection and hippocampal networks are vulnerable to AD-related pathology. Targeting these networks with tCS in an early phase may be a valid disease-delaying approach. The hippocampus cannot be stimulated directly, but is closely connected with the angular gyrus. By stimulating the angular gyrus during memory performance makes the recollection network more susceptible and therefore, we hypothesize that indirect effects might be detected in the hippocampus. Further, we will investigate the neural and cognitive effects of single vs multiple sessions. Knowledge about the (long-term)