Publications de Traian Popa | EPFL Graph Search

Noninvasive modulation of the hippocampal-entorhinal complex during spatial navigation in humans

Olaf Blanke, Elena Beanato, Hyukjun Moon, Esra Neufeld, Friedhelm Christoph Hummel, Maximilian Jonas Wessel, Baptiste Gauthier, Traian Popa, Pierre Theopistos Vassiliadis, Emanuela De Falco, Pauline Menoud, Fabienne Windel

Because of the depth of the hippocampal-entorhinal complex (HC-EC) in the brain, understanding of its role in spatial navigation via neuromodulation was limited in humans. Here, we aimed to better elucidate this relationship in healthy volunteers, using tr ...

American Association for the Advancement of Science (AAAS)2024

Non-invasive stimulation of the human striatum disrupts reinforcement learning of motor skills

Elena Beanato, Esra Neufeld, Friedhelm Christoph Hummel, Takuya Morishita, Maximilian Jonas Wessel, Traian Popa, Pierre Theopistos Vassiliadis, Julie Duqué, Fabienne Windel

Reinforcement feedback can improve motor learning, but the underlying brain mechanisms remain underexplored. In particular, the causal contribution of specific patterns of oscillatory activity within the human striatum is unknown. To address this question, ...

Nature Portfolio2024

Native learning ability and not age determines the effects of brain stimulation

Pablo Maceira Elvira, Friedhelm Christoph Hummel, Anne-Christine Schmid, Andéol Geoffroy Cadic-Melchior, Traian Popa

Healthy aging often entails a decline in cognitive and motor functions, affecting independence and quality of life in older adults. Brain stimulation shows potential to enhance these functions, but studies show variable effects. Previous studies have tried ...

2024

Physiology-inspired bifocal fronto-parietal tACS for working memory enhancement

Sylvain Jean-François Harquel, Pablo Maceira Elvira, Friedhelm Christoph Hummel, Traian Popa

Aging populations face significant cognitive challenges, particularly in working memory (WM). Transcranial alternating current stimulation (tACS) offer promising avenues for cognitive enhancement, especially when inspired by brain physiology. This study (N ...

2024

Noninvasive theta-burst stimulation of the human striatum enhances striatal activity and motor skill learning

Elena Beanato, Pablo Maceira Elvira, Esra Neufeld, Friedhelm Christoph Hummel, Takuya Morishita, Maximilian Jonas Wessel, Chang-Hyun Park, Traian Popa, Pierre Theopistos Vassiliadis, Pauline Menoud, Fabienne Windel

The stimulation of deep brain structures has thus far only been possible with invasive methods. Transcranial electrical temporal interference stimulation (tTIS) is a novel, noninvasive technology that might overcome this limitation. The initial proof-of-co ...

Nature Portfolio2023

Depotentiation of associative plasticity is intact in Parkinson's disease with mild dyskinesia

Traian Popa

Objective: Depotentiation of homosynaptic plasticity of the primary motor cortex (M1) is impaired in patients with Parkinson's disease (PD) who have developed dyskinesias. In this exploratory study, we tested whether this holds true for heterosynaptic plas ...

ELSEVIER SCI LTD2022

Toward individualized medicine in stroke-The TiMeS project: Protocol of longitudinal, multi-modal, multi-domain study in stroke

Jean-Philippe Thiran, Dimitri Nestor Alice Van De Ville, Olaf Blanke, Philip Egger, Sylvain Jean-François Harquel, Silvestro Micera, Nathalie Heidi Meyer, Elena Beanato, Valérie Rita Madeleine Zufferey, Gabriel Girard, Julia Brügger, Friedhelm Christoph Hummel, Takuya Morishita, Maximilian Jonas Wessel, Philipp Johannes Koch, Estelle Emeline Raffin, Andéol Geoffroy Cadic-Melchior, Traian Popa, Pauline Menoud, Lisa Aïcha Mireille Julie Fleury

Despite recent improvements, complete motor recovery occurs in < 15% of stroke patients. To improve the therapeutic outcomes, there is a strong need to tailor treatments to each individual patient. However, there is a lack of knowledge concerning the preci ...

FRONTIERS MEDIA SA2022

Transcranial magnetic stimulation of the brain: What is stimulated? - A consensus and critical position paper

Traian Popa

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 potentia ...

ELSEVIER IRELAND LTD2022

Inter-Individual Variability in Motor Output Is Driven by Recruitment Gain in the Corticospinal Tract Rather Than Motor Threshold

Traian Popa

Variability in the response of individuals to various non-invasive brain stimulation protocols is a major problem that limits their potential for clinical applications. Baseline motor-evoked potential (MEP) amplitude is the key predictor of an individual's ...

MDPI2022

Dissecting motor skill acquisition: Spatial coordinates take precedence

Pablo Maceira Elvira, Friedhelm Christoph Hummel, Takuya Morishita, Anne-Christine Schmid, Maximilian Jonas Wessel, Traian Popa

Practicing a previously unknown motor sequence often leads to the consolidation of motor chunks, which enable its accurate execution at increasing speeds. Recent imaging studies suggest the function of these structures to be more related to the encoding, s ...

AMER ASSOC ADVANCEMENT SCIENCE2022

Replicable effect of cortical-paired associative stimulation on response inhibition as a function of age

Traian Popa

2021

Plastic responsiveness of motor cortex to paired associative stimulation depends on cerebellar input

Traian Popa

Objective: The extent of plastic responses of motor cortex (M1) to paired associative stimulation (PAS) varies among healthy subjects. Continuous theta-burst stimulation (cTBS) of cerebellum enhances the mean PAS-induced plasticity in groups of healthy sub ...

ELSEVIER IRELAND LTD2021

The role of the inferior parietal lobule in writer's cramp

Traian Popa

Humans have a distinguishing ability for fine motor control that is subserved by a highly evolved cortico-motor neuronal network. The acquisition of a particular motor skill involves a long series of practice movements, trial and error, adjustment and refi ...

OXFORD UNIV PRESS2020

The effect of frontoparietal paired associative stimulation on decision-making and working memory

Traian Popa

Previous single-site neurostimulation experiments have unsuccessfully attempted to shift decision-making away from habitual control, a fast, inflexible cognitive strategy, towards goal-directed control, a flexible, though computationally expensive strategy ...

2019

Consensus Paper: Experimental Neurostimulation of the Cerebellum

Traian Popa

The cerebellum is best known for its role in controlling motor behaviors. However, recent work supports the view that it also influences non-motor behaviors. The contribution of the cerebellum towards different brain functions is underscored by its involve ...

Springer2019

Wearable technology in stroke rehabilitation: towards improved diagnosis and treatment of upper-limb motor impairment

Pablo Maceira Elvira, Friedhelm Christoph Hummel, Anne-Christine Schmid, Traian Popa

Stroke is one of the main causes of long-term disability worldwide, placing a large burden on individuals and society. Rehabilitation after stroke consists of an iterative process involving assessments and specialized training, aspects often constrained by ...

BioMed Central2019

Feasibility of home-based, self-applied transcranial direct current stimulation to enhance motor learning in middle-aged and older adults

Pablo Maceira Elvira, Friedhelm Christoph Hummel, Anne-Christine Schmid, Traian Popa

2019