Andrea Antal

Universitätsmedizin Göttingen · Department of Neurology

Nicht-invasive Hirnstimulation ist ein sehr vielversprechendes Feld in der therapeutischen Anwendung von Methoden der klinischen Neurophysiologie. Die Vielzahl der physikalisch möglichen Stimulationsparameter erfordern eine detaillierte Kenntnis der einzelnen Verfahren, wie sie in diesem Curriculum vermitteln werden.

Temporal interference stimulation (TIS) aims at targeting deep brain areas during transcranial electrical alternating current stimulation (tACS) by generating interference fields at depth. Although its modulatory effects have been demonstrated in animal and human models and stimulation studies, direct experimental evidence is lacking for its utilit...

Aging is often accompanied by a decline in cognitive functions, with memory being particularly affected. Recent studies suggest that cognitive training sessions that teach memory strategies relevant to daily life may benefit seniors who live in the community. However, it is possible that the cognitive improvement observed in these programs results...

Background: Low intensity transcranial electrical stimulation (tES) and meditation are two promising, yet variable, non-pharmacological interventions. Growing research is investigating combined effects of both techniques on one's cognitive, emotional, and physical health. Objective: This article reviews the current research that combines tES and...

Background This double-blinded, randomized and sham-controlled pilot clinical trial aimed to investigate the preliminary clinical efficacy and feasibility of combining mindfulness meditation (MM) and transcranial direct current stimulation (tDCS) for pain and associated symptoms in patients with fibromyalgia syndrome (FMS). Methods Included FMS pa...

Objective Although relatively costly and non-scalable, non-invasive neuromodulation interventions are treatment alternatives for neuropsychiatric disorders. The recent developments of highly-deployable transcranial electric stimulation (tES) systems, combined with mobile-Health technologies, could be incorporated in digital trials to overcome metho...

Non-invasive electrical stimulation methods, such as transcranial alternating current stimulation (tACS), are increasingly used in human neuroscience research and offer potential new avenues to treat neurological and psychiatric disorders. However, their often variable effects have also raised concerns in the scientific and clinical communities. Th...

Transcranial (electro)magnetic stimulation (TMS) is currently the method of choice to non-invasively induce neural activity in the human brain. A single transcranial stimulus induces a time-varying electric field in the brain that may evoke action potentials in cortical neurons. The spatial relationship between the locally induced electric field an...

Attempts to enhance human memory and learning ability have a long tradition in science. This topic has recently gained substantial attention because of the increasing percentage of older individuals worldwide and the predicted rise of age-associated cognitive decline in brain functions. Transcranial brain stimulation methods, such as transcranial m...

Background Anxiety, conduct and depressive disorders represent three highly prevalent psychiatric conditions in adolescents. A shared underpinning of these disorders is a shortcoming in emotion regulation, connected to the functioning of the ventromedial prefrontal cortex. Thus, an intervention able to target the suggested neural correlate seems to...

Objective The influence of the TMS-parameters on the efficacy and reliability to induce diaphragmatic motor-evoked potentials (diMEPs) has not been studied so far. Therefore, the objective of the present research is to probe the role of TMS- waveform (monophasic- [Mo] vs. biphasic-pulses [Bi]) and current direction (posterior-anterior [Pa] vs. ante...

Low-intensity transcranial electrical stimulation (tES), including alternating or direct current stimulation, applies weak electrical stimulation to modulate the activity of brain circuits. Integration of tES with concurrent functional MRI (fMRI) allows for the mapping of neural activity during neuromodulation, supporting causal studies of both bra...

Objective: Hemianopia following occipital stroke is believed to be mainly due to local damage at or near the lesion site. Yet, MRI studies suggest functional connectivity network (FCN) reorganization also in distant brain regions. Because it is unclear if reorganization is adaptive or maladaptive, compensating for, or aggravating vision loss, we c...

Noninvasive brain stimulation techniques (NiBS) have gathered substantial interest in the study of dementia, considered their possible role in help defining diagnostic biomarkers of altered neural activity for early disease detection and monitoring of its pathophysiological course, as well as for their therapeutic potential of boosting residual cog...

Background At early stages, dementia disorders share similar clinical symptoms. For an appropriate classification, more practical and non‐invasive diagnostic methods are needed. Transcranial magnetic stimulation (TMS) assess non‐invasively the imbalance of cortical excitability and related neurotransmitters levels in the brain(1‐3). Characterizing...

The world's population is aging. With this comes an increase in the prevalence of age-associated diseases, which amplifies the need for novel treatments to counteract cognitive decline in the elderly. One of the recently discussed non-pharmacological approaches is transcranial direct current stimulation (tDCS). TDCS delivers weak electric currents...

Because current flow cannot be measured directly in the intact retina or brain, current density distribution models were developed to estimate it during magnetic or electrical stimulation. A paradigm is now needed to evaluate if current flow modeling can be related to physiologically meaningful signs of true current distribution in the human brain....

This is the second chapter of the series on the use of clinical neurophysiology for the study of movement disorders. It focusses on methods that can be used to probe neural circuits in brain and spinal cord. These include use of spinal and supraspinal reflexes to probe the integrity of transmission in specific pathways; transcranial methods of brai...

Through neuromodulation of neural activity, transcranial alternating current stimulation (tACS) interacts with neural oscillations in a frequency- and phase-specific manner, thereby influencing human brain function. Currents are applied at the scalp with intensities up to 4 mA peak to peak (except for electroconvulsive therapy with much higher inte...

Introduction: 1) During tES, increasing intracellular Ca2+ levels beyond those needed for inducing LTP may collapse aftereffects. 2) State-dependent plastic aftereffects are reduced when applied during muscle activation as compared to rest. 3) Cortical surround inhibition by antagonistic muscle activation inhibits the center-innervated agonist. O...

Background: Occipital strokes often cause permanent homonymous hemianopia leading to significant disability. In previous studies, non-invasive electrical brain stimulation (NIBS) has improved vision after optic nerve damage and in combination with training after stroke. Objective: We explored different NIBS modalities for rehabilitation of hemia...

Background Low intensity transcranial electrical stimulation (tES), including alternating or direct current stimulation (tACS or tDCS), applies weak electrical stimulation to modulate brain circuits. Integration of tES with concurrent functional magnetic resonance imaging (fMRI) allows neuromodulation of brain regions while mapping network function...

As the field of noninvasive brain stimulation (NIBS) expands there is a growing need for comprehensive guidelines on training practitioners in the safe and effective administration of NIBS techniques in their various research and clinical applications. This article provides recommendations on the structure and content of this training. Three differ...

Background: Low intensity, high-frequency transcranial alternating current stimulation (tACS) applied over the motor cortex decreases the amplitude of motor evoked potentials. This double-blind, placebo-controlled parallel group study aimed to test the efficacy of this method for acute management of migraines. Methods: The patients received either...

s Sensorimotor mu-alpha rhythm reflects the state of cortical excitability. Repetitive transcranial magnetic stimulation (rTMS) can modulate neural synchrony by inducing periodic electric fields (E-fields) in the cortical networks. We hypothesized that the increased synchronization of mu-alpha rhythm would inhibit the corticospinal excitability ref...

This article is based on a consensus conference, promoted and supported by the International Federation of Clinical Neurophysiology (IFCN), which took place in Siena (Italy) in October 2018. The meeting intended to update the ten-year-old safety guidelines for the application of transcranial magnetic stimulation (TMS) in research and clinical setti...

For decades visual field defects were considered irreversible because it was thought that in the visual system the regeneration potential of the neuronal tissues is low. Nevertheless, there is always some potential for partial recovery of the visual field defect that can be achieved through induction of neuroplasticity. Neuroplasticity refers to th...

The two most frequently used techniques for the non-invasive modulation of brain activity are repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS). These techniques have repeatedly been used to modulate the activity of a given area within a neuronal network to study pathophysiological changes in mig...

Cognitive control is a mental process, which underlies adaptive goal-directed decisions. Previous studies have linked cognitive control to electrophysiological fluctuations in the θ band and θ-γ cross-frequency coupling (CFC) arising from the cingulate and frontal cortices. However, to date, the behavioral consequences of different forms of θ-γ CFC...

Repetitive transcranial magnetic stimulation (rTMS) and transcranial electrical stimulation (TES) are noninvasive brain stimulation techniques that are increasingly used as therapeutic approaches in psychiatric disorders. As for any therapeutic intervention, including drugs, it is necessary to delineate their safety limits, including adverse effect...

Non-invasive neuromodulation techniques such as transcranial direct current stimulation (tDCS) enable researchers and health care professionals to gain unique insight into brain functions and to treat a number of neurological and psychiatric conditions. Repeated applications of anodal tDCS over the primary motor cortex (M1) have been shown to produ...

Background The COVID-19 pandemic has broadly disrupted biomedical treatment and research including non-invasive brain stimulation (NIBS). Moreover, the rapid onset of societal disruption and evolving regulatory restrictions may not have allowed for systematic planning of how clinical and research work may continue throughout the pandemic or be rest...

PurposeIdentifying factors that affect recovery or restoration of neurological function is a key goal of rehabilitation in neurology and ophthalmology. One such factor can be prolonged mental stress, which may be not only the consequence of nervous system damage but also a major risk factor, or cause, of neural inactivation. Using the visual system...

Cognitive control is a hypothetical mental process, which underlies adaptive goal-directed decisions. Previous studies have linked cognitive control to electrophysiological fluctuations in the theta band and theta-gamma cross-frequency coupling (CFC) arising from the cingulate and frontal cortices. Yet, to date the behavioral consequences of differ...

Understanding the mechanisms by which intermittent theta burst stimulation (iTBS) protocols exert changes in the default-mode network (DMN) is paramount to develop therapeutically more effective approaches in the future. While a full session (3000 pulses) of 10 Hz repetitive transcranial magnetic stimulation (HF-rTMS) reduces the functional connect...

The visual system has one of the most complex structures of all sensory systems and is perhaps the most important sense for everyday life. Its functional organization was extensively studied for decades in animal and humans, for example by correlating circumscribed anatomical lesions in patients with the resulting visual dysfunction. During the pas...

Low vision is still a little known area of ophthalmology and requires constant study, a multifactorial approach, multiple skills and a two-way dialogue with the other sectors of the ophthalmological discipline. The lack of communication among experts hampers a higher level of cognition about this topic. This volume, in the philosophy of Low Vision...

Among the brain regions involved in the aesthetic evaluation of paintings, the prefrontal cortex seems to play a pivotal role. In particular, consistent neuroimaging evidence indicates that activity in the dorsolateral prefrontal cortex (mainly in the left hemisphere) and in medial and orbital sectors of the prefrontal cortex is linked to viewing a...

Noninvasive neuromodulation, including repetitive trans­cranial magnetic stimulation (rTMS) and direct current stimulation (tDCS), provides researchers and health care professionals with the ability to gain unique insights into brain functions and treat several neurological and psychiatric conditions. Undeniably, the number of published research an...

Behavioral response conflict arises in the color-word Stroop task and triggers the cognitive control network. Midfrontal theta-band oscillations correlate with adaptive control mechanisms during and after conflict resolution. In order to prove causality, in two experiments, we applied transcranial alternating current stimulation (tACS) at 6 Hz to t...

Transcranial electrical stimulation (tES) aims to alter brain function non-invasively by applying current to electrodes on the scalp. Decades of research and technological advancement are associated with a growing diversity of tES methods and the associated nomenclature for describing these methods. Whether intended to produce a specific response s...

Understanding the mechanisms by which transcranial magnetic stimulation protocols exert changes in the default mode network (DMN) is paramount to develop therapeutically more effective approaches in the future. A full session (3000 pulses) of 10 Hz repetitive transcranial magnetic stimulation (HF-rTMS) reduces the functional connectivity (FC) of th...

High frequency repetitive transcranial magnetic stimulation (HF-rTMS) delivered to the left dorsolateral prefrontal cortex (DLPFC) is an effective treatment option for treatment resistant depression. However, the underlying mechanisms of a full session of HF-rTMS in healthy volunteers have not yet been described. Here we investigated, with a person...

Background Modifying brain activity using non-invasive, low intensity transcranial electrical brain stimulation (TES) has rapidly increased during the past 20 years. Alternating current stimulation (ACS), for example, has been shown to alter brain rhythm activities and modify neuronal functioning in the visual system. Daily application of transorbi...

When our attention is decoupled from an ongoing task and becomes coupled to thoughts and feelings not being subject to task engagement, we are mind-wandering. This transient and pervasive mental process can occupy a considerable amount of our waking hours. Mind-wandering is understood to exert both positive and negative effects on well-being, and h...

Transcranial direct current stimulation (tDCS) is a non‐invasive brain stim‐ulation method that is frequently used to study cortical excitability changes and their impact on cognitive functions in humans. While most stimulators are capable of operating in double‐blind mode, the amount of discomfort ex‐perienced during tDCS may break blinding. There...

Transcranial direct current stimulation (tDCS) has been proposed to be able to modulate different cognitive functions. However, recent meta‐analyses conclude that its efficacy is still in question. Recently, an increase in subjects’ propensity to mind‐wander has been reported as a consequence of anodal stimulation of the left dorsolateral prefronta...

In 2015, a seminal study reported that anodal transcranial direct current stimulation (tDCS) above the left DLPFC could increase MW propensity in healthy adults (Axelrod et al., 2015). Participants were asked to perform the Sustained Attention to Response Task (SART), while MW was quantified using thought-probes both during and immediately followin...

Non-invasive neuromodulation, using low intensity transcranial direct current stimulation (tDCS), provides scientists and medical doctors with the ability to gain fundamental insight into brain functions and to treat several neurological and psychiatric conditions. Due to this circumstance, the use of tDCS, including the off-label applications, is...

Inactive interventions can have significant effects on cognitive performance. Understanding the generation of these cognitive placebo/nocebo effects is crucial for evaluating the cognitive impacts of interventional methods, such as non-invasive brain stimulation (NIBS). We report both cognitive placebo and nocebo effects on reward-based learning pe...

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method that is frequently used to study cortical excitability changes and their impact on cognitive functions in humans. While most stimulators are capable of operating in double-blind mode, the amount of discomfort experienced during tDCS may break blinding. Therefo...

Transcranial direct current stimulation (tDCS) is increasingly evaluated for a myriad of clinical indications and performance enhancement mainly related to cognitive and motor applications. As a result tDCS has been tested with diverse inclusion criteria and subject populations. tDCS is customized for applications by many factors, including stimula...

High frequency repetitive TMS (HF-rTMS) to the left dorsolateral prefrontal cortex (DLPFC) is an approved option for the treatment of depression, but there is also much variability in the resulting antidepressant response. This variability is believed to arise from various factors, an important one of which being the method by which rTMS is targete...

Direct current stimulation is a neuromodulatory noninvasive brain stimulation tool, which was first introduced in animal and human experiments in the 1950s, and added to the standard arsenal of methods to alter brain physiology as well as psychological, motor, and behavioral processes and clinical symptoms in neurological and psychiatric diseases a...

Inactive interventions can have significant effects on cognitive performance. Understanding the generation of these cognitive placebo/nocebo effects is crucial for evaluating the cognitive impacts of interventional methods, such as non-invasive brain stimulation (NIBS). We report both cognitive placebo and nocebo effects on reward-based learning pe...

Background: Phase-amplitude cross-frequency coupling (PAC) is characterized by the modulation of the power of a fast brain oscillation (e.g., gamma) by the phase of a slow rhythm (e.g., theta). PAC in different sub- and neocortical regions is known to underlie effective neural communication and correlates with successful long-term memory formation...

This dataset contains three repeated measures of a standard reward-based reinforcement-learning task from 29 healthy male individuals who participated in three experimental sessions exploring cognitive placebo effects on reward learning. The dataset includes behavioural data (accuracy, reaction times) during learning and transfer, estimates of mode...

Transcranial direct current stimulation (tDCS) has been proposed to be a useful tool to modulate different cognitive functions. However, recent meta-analyses conclude that its efficacy is still in question. Recently, an increase in subjects' propensity to mind-wander has been reported as a consequence of anodal stimulation of the left dorsolateral...