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Abstracts / Brain Stimulation 10 (2017) e21ee45
Abstract Both invasive and non-invasive stimulation paradigms are emerging as strong alternatives to pharmaceutical treatments and have further raised the fascinating prospect of manipulating neural activity in a controlled manner. Recently, the interaction between applied stimulation and cortical oscillations has raised much attention: weak electric fields e delivered at a particular pace e can not only influence the behavior of single neurons, but also extends at higher spatial scales by shaping the way populations synchronize and communicate with each other. Capitalizing on this, numerous studies have shown that stimulation can be tuned to selectively engage endogenous brain oscillations and influence perception and task performance, effectively making patterned stimulation a potential means of controlling - or restoring - neural circuit’s function. Inspired by recent experimental findings, we here provide modeling insights regarding the link between periodic stimulation parameters such as amplitude and frequency and the response of stimulated neural populations. Our results suggest that rhythmic stimulation forms the basis of a control paradigm in which one can manipulate the intrinsic oscillatory properties of stimulated networks via a plurality of input-driven mechanisms. We also use principles from control theory and non-linear dynamics to understand the mechanisms behind persistent effects commonly observed in neuronal networks after stimulation. These results open new perspectives on the manipulation of synchronous neural activity for basic and clinical research, while accelerating the development of new paradigms meant to restore cognitive functions based on the selective entrainment of brain rhythms.
of tDCS, participants were categorized as low or high skill based on performing below or above average on standardized assessments. All participants received real or sham stimulation to the left inferior parietal lobe for twenty minutes before training on words in an artificial orthography over the course of three days, receiving explicit training on ten novel words each day. Understanding of the artificial orthography was assessed at a pre-training baseline session, the end of each of the three training sessions, an immediate post-training session, and a delayed post-training session about four weeks after training. All groups demonstrated learning of the artificial orthography, however, the low skill stimulation group achieved higher accuracy throughout training compared to the low skill sham group. Further, both stimulation groups showed greater performance at the delayed post-training session compared to both sham groups. Our results showed that stimulation can improve the learning trajectory of low skill individuals and lead to greater maintenance of newly learned material four weeks later. These results indicate tDCS may be an effective tool for reading intervention for those that struggle to learn to read. Abstract #7 E-MEDITATION: A NOVEL PARADIGM USING TDCS TO ENHANCE MINDFULNESS MEDITATION Bashar W. Badran*1, Chris W. Austelle 1, Nicole R. Smith 1, Chloe E. Glusman 1, Brett Froeliger 2, Eric L. Garland 3, Jeffrey J. Borckardt 1, Mark S. George 1, Baron Short 1. 1 Brain Stimulation Laboratory, Department of Psychiatry, MUSC, Charleston, SC, USA; 2 Department of Neuroscience, MUSC, Charleston, SC, USA; 3 University of Utah, Salt Lake City, Utah, USA
Abstract #5 TDCS METAPLASTICITY AND ASTROCYTIC CALCIUM IN MICE Hajime Hirase*, Hiromu Monai. RIKEN Brain Science Institute, Wako, Saitama, Japan
Abstract Background
Abstract Global brain state dynamics regulate plasticity in local cortical circuits but the underlying cellular and molecular mechanisms are unclear. In an attempt to optically monitor the brain activity of wide brain areas, we made a transgenic mouse (G7NG817, available from RIKEN BRC, strain ID: RBRC09650) that expresses the genetic Ca2+ indicator G-CaMP7 in astrocytes and a subpopulation of neurons [1]. Using this mouse, we explored the cortical Ca2+ dynamics during transcranial direct current stimulation (tDCS), a treatment known to ameliorate various neurological conditions and enhance memory and cognition in humans. Here, we would like to present the results and interpretations that we published recently [1,2]. We found that tDCS induced large-amplitude astrocytic Ca2+ surges across the entire cortex with no obvious changes in cortical neuronal activity. Moreover, sensory evoked cortical responses were enhanced after tDCS, whereas this enhancement was not seen in a mouse model in which astrocytic Ca2+ surges are largely diminished, suggesting that tDCS alters the plasticity of the cortex (i.e. metaplasticity) through astrocytic Ca2+/IP3 signaling. Abstract #6 THE EFFECT OF TDCS AND PHONEMIC DECODING ABILITY ON LEARNING TO READ Jessica Wise Younger*, James R. Booth. University of Texas at Austin, Austin, Texas, USA
Abstract tDCS has successfully been used to improve reading ability, particularly in low skill adults. However, no research has examined how tDCS might affect learning new sound to symbol correspondences (phonemic decoding), as would be necessary for tDCS-based reading interventions. In the current study, we examine whether tDCS can affect adults learning to read an artificial orthography. To determine whether skill would impact the effect
Western medicine has seen increased interest in mindfulness-based interventions (MBIs) for the treatment of neuropsychiatric disorders. MBIs are associated with improvements in physical, mental, and social wellbeing, along with decreased feelings of stress, anxiety, depressive symptoms, rumination, and cognitive reactivity. We have developed a novel paradigm we are calling “E-meditation,” in which tDCS is paired with guided mindfulness meditation to reduce the learning curve of meditation and enhance its mood effects.
Methods 15 healthy individuals (7 female, mean age ¼ 28.2 y/o) were recruited for this double-blind, sham-controlled, crossover study. Following a screening visit, participants returned for 3 weekly E-meditation visits. Each 20min Emeditation visit consisted of one of three randomized tDCS stimulation conditions (sham, active 1mA, or 2mA; anode - EEG F8, cathode e left supraorbital). Stimulation was synchronized with a guided mindfulness recording. Mood visual analog scales and mindfulness scales were conducted before and after each meditation visit.
Results The four mood states with largest positive effects of active E-meditation compared to sham were: sad, excited, restless and calm. Of the five facets of the FFMQ, E-meditation only influenced Acting with Awareness and Observing facets. 1mA E-meditation showed a significant mean difference from baseline change in the Acting with Awareness facet as compared to sham (paired t-test, p¼0.0175).
Conclusions E-meditation is a novel approach to a centuries old tradition of meditation for psychological well-being. Additional longer-term (e.g. 8-weeks) trials of the effectiveness of E-Meditation are warranted.