Giulio Ruffini

Giulio Ruffini
Neuroelectrics · Research

BA Physics and Mathematics, MSc Physics, PhD Physics

About

276
Publications
68,897
Reads
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6,011
Citations
Citations since 2016
147 Research Items
4216 Citations
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
Introduction
Giulio got a BA in math and physics from Berkeley and a PhD in theoretical physics from UC Davis/LANL. In 2000 he and others founded Starlab to transform science into technologies with impact. He believes that neuromodulation will make great advances thanks to the union of precision multifocal stimulation technologies with advanced biophysical and computational models, EEG and fMRI. His recent paper on brain-to-brain communication was the 9th most shared paper of 2014. He co-founded Neuroelectrics in 2011 to deliver brain stimulation solutions to the clinical market.
Additional affiliations
January 2000 - present
Starlab Barcelona SL
Description
  • http://starlab.es
January 2000 - March 2019
Starlab Barcelona SL
Position
  • Head of Department
February 1996 - November 1999
IEEC Institute of Space Studies of Catalonia
Position
  • PostDoc Position
Education
September 2010 - April 2011
Universidad de Navarra
Field of study
  • General Management
September 1988 - March 1995
University of California, Davis
Field of study
  • Physics
August 1986 - June 1988
University of California, Berkeley
Field of study
  • Mathematics and Physics

Publications

Publications (276)
Article
In this paper, we present a unifying framework to study consciousness based on algorithmic information theory (AIT). We take as a premise that “there is experience” and focus on the requirements for structured experience ([Formula: see text]) — the spatial, temporal, and conceptual organization of our first-person experience of the world and of our...
Article
Full-text available
Objective: In partial epilepsies, interictal epileptiform discharges (IEDs) are paroxysmal events observed in epileptogenic and non-epileptogenic zones. IEDs' generation and recurrence are subject to different hypotheses: they appear through glutamatergic and GABAergic processes; they may trigger seizures or prevent seizure propagation. This paper...
Article
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...
Article
Mental health disorders and substance use disorders are a leading cause of morbidity and mortality worldwide and one of the most important challenges for public health systems. While evidence-based psychotherapy is generally pursued to address mental health challenges, psychological change is often hampered by non-adherence to treatments, relapses,...
Preprint
Here we discuss the impact of issues recently raised about theories of consciousness in light of the so-called "unfolding argument" and the more general falsification requirements on causal structure theories of consciousness. These arguments potentially affect the algorithmic information theory of consciousness (KT), where the structure of a compu...
Preprint
Full-text available
A topic of growing interest in computational neuroscience is the discovery of fundamental principles underlying global dynamics and self-organization of the brain. Statistical physics offers powerful tools to analyze complex many-body systems and has delivered computational models such as the generalized Ising model, one of the simplest known syste...
Article
Full-text available
Purpose Transcranial electrical current stimulation (tES or tCS, as it is sometimes referred to) has been proposed as non-invasive therapy for pharmacoresistant epilepsy. This technique, which includes direct current (tDCS) and alternating current (tACS) stimulation involves the application of weak currents across the cortex to change cortical exci...
Article
Work in the last two decades has shown that neural mass models (NMM) can realistically reproduce and explain epileptic seizure transitions as recorded by electrophysiological methods (EEG, SEEG). In previous work, advances were achieved by increasing excitation and heuristically varying network inhibitory coupling parameters in the models. Based on...
Preprint
Cortical function emerges from the interactions of multi-scale networks that may be studied at a high level using neural mass models (NMM), representing the mean activity of large numbers of neurons. In order to properly reproduce experimental data, these models require the addition of further elements. Here we provide a framework integrating condu...
Preprint
Objective We provide a systematic framework for the quantification of the effect of externally applied weak electric fields on realistic neuron compartment models as captured by physiologically relevant quantities such as the membrane potential or transmembrane current as a function of the orientation of the field. Approach We define a response fu...
Article
Full-text available
Over the past few years, the possibility of modulating fast brain oscillatory activity in the gamma (γ) band through transcranial alternating current stimulation (tACS) has been discussed in the context of both cognitive enhancement and therapeutic scenarios. However, the effects of tACS targeting regions outside the motor cortex, as well as its sp...
Preprint
Objective Stereotactic-EEG (SEEG) and scalp EEG recordings can be modeled using mesoscale neural mass population models (NMM). However, the relationship between those mathematical models and the physics of the measurements is unclear. In addition, it is challenging to represent SEEG data by combining NMMs and volume conductor models due to the inte...
Preprint
Full-text available
Neural mass models (NMMs) are designed to reproduce the collective dynamics of neuronal populations. A common framework for NMMs assumes heuristically that the output firing rate of a neural population can be described by a static nonlinear transfer function (NMM1). However, a recent exact mean-field theory for quadratic integrate-and-fire (QIF) ne...
Article
Full-text available
Purpose Previous studies have linked gait variability to resting-state functional connectivity between the dorsal attention network (DAN) and the default network (DN) in the brain. The purpose of this study was to examine the effects of a novel transcranial direct current stimulation (tDCS) paradigm designed to simultaneously facilitate the excitab...
Preprint
We present a unifying framework to study consciousness based on algorithmic information theory (AIT). We take as a premise that ``there is experience'' and focus on the requirements for structured experience (S)--- the spatial, temporal, and conceptual organization of our first-person experience of the world and of ourselves as agents in it. Our st...
Article
Purpose: Lennox-Gastaut Syndrome (SLG) is a severe form of childhood refractory epilepsy. Only one pilot study has been conducted using cathodal transcranial direct current stimulation (c-tDCs; 2mAx30minx5days) in LGS with promising results (-99% seizure reduction at 5 days). Our aim was to explore and replicate the efficacy and safety of 10 daily...
Article
Objective In epilepsy, multichannel transcranial direct electrical stimulation (tDCS) is applied to decrease cortical activity through the delivery of weak currents using several scalp electrodes. We investigated the long-term effects of personalized, multisession, stereotactic-EEG (SEEG)-targeted multichannel tDCS on seizure frequency (SF) and fun...
Article
Objective: Metal implants impact the dosimetry assessment in electrical stimulation techniques. Therefore, they need to be included in numerical models. While currents in the body are ionic, metals only allow electron transport. In fact, charge transfer between tissues and metals requires electric fields to drive electrochemical reactions at the i...
Article
Full-text available
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...
Article
Full-text available
Major depressive disorder (MDD) is a worldwide cause of disability in older age, especially during the covid pandemic. Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique that has shown encouraging efficacy for treatment of depression. Here, we investigate the feasibility of an innovative protocol where tDCS i...
Preprint
Full-text available
The prospect of personalized computational modeling in neurological disorders, and in particular in epilepsy, is poised to revolutionize the field. Work in the last two decades has demonstrated that neural mass models (NMM) can realistically reproduce and explain epileptic seizure transitions as recorded by electrophysiological methods (EEG, SEEG)....
Article
Full-text available
Background Alzheimer’s disease (AD) is associated with alterations in cortical perfusion that correlate with cognitive impairment. Recently, neural activity in the gamma band has been identified as a driver of arteriolar vasomotion while, on the other hand, gamma activity induction on preclinical models of AD has been shown to promote protein clear...
Preprint
Full-text available
Background Metal implants impact the dosimetry assessment in electrical stimulation techniques. Therefore, they need to be included in numerical models. While currents in the body are ionic, metals only allow electron transport. In fact, charge transfer between tissues and metals requires electric fields to drive the electrochemical reactions at th...
Article
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...
Article
Full-text available
Methodological studies investigating transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (lDLPFC) in paediatric populations are limited. Therefore, we investigated in a paediatric population whether stimulation success of multichannel tDCS over the lDLPFC depends on concurrent task performance and individual...
Article
Full-text available
Combining non-invasive brain stimulation (NIBS) with resting-state functional magnetic resonance imaging (rs-fMRI) is a promising approach to characterize and potentially optimize the brain networks subtending cognition that changes as a function of age. However, whether multifocal NIBS approaches are able to modulate rs-fMRI brain dynamics in aged...
Preprint
Full-text available
Neural mass models such as the Jansen-Rit system provide a practical framework for representing and interpreting electrophysiological activity (1–6) in both local and global brain models (7). However, they are only partly derived from first principles. While the post-synaptic potential dynamics in NMM are inferred from data and can be grounded on d...
Article
Objective Among older adults, the ability to stand or walk while performing cognitive tasks (i.e., dual-tasking) requires coordinated activation of several brain networks. In this multi-center, double-blinded, randomized, and sham-controlled study, we examined the effects of modulating the excitability of the left dorsolateral prefrontal cortex (L-...
Article
Full-text available
Alzheimer's disease (AD) is an irreversible, progressive brain disorder that can cause dementia (Alzheimer's disease-related dementia, ADRD) with growing cognitive disability and vast physical, emotional, and financial pressures not only on the patients but also on caregivers and families. Loss of memory is an early and very debilitating symptom in...
Article
Purpose: Animal and proof-of-principle human studies suggest that cathodal transcranial direct current stimulation may suppress seizures in drug-resistant focal epilepsy. The present study tests the safety, tolerability, and effect size of repeated daily cathodal transcranial direct current stimulation in epilepsy have not been established, limiti...
Article
Full-text available
Background Autism spectrum disorder (ASD) is characterized by impaired social communication and interaction, and stereotyped, repetitive behaviour and sensory interests. To date, there is no effective medication that can improve social communication and interaction in ASD, and effect sizes of behaviour-based psychotherapy remain in the low to mediu...
Article
Transcranial direct current stimulation (tDCS) applied over the prefrontal cortex has been shown to improve behavioral responsiveness in patients with disorders of consciousness following severe brain injury, especially those in minimally conscious state (MCS). However, one potential barrier of clinical response to tDCS is the timing of stimulation...
Article
Full-text available
Background Neural oscillations in the cerebral cortex are associated with a range of cognitive processes and neuropsychiatric disorders. However, non-invasively modulating oscillatory activity remains technically challenging, due to limited strength, duration, or non-synchronization of stimulation waveforms with endogenous rhythms. Objective /Hypo...
Chapter
Full-text available
The right matching of patients to an intended treatment is routinely performed by doctor and physicians in healthcare. Improving doctor’s ability to choose the right treatment can greatly speed up patient’s recovery. In a clinical study on Disorders of Consciousness patients in Minimal Consciousness State (MCS) have gone through transcranial Electr...
Article
Full-text available
Background Transcranial direct current stimulation (tDCS), a neuromodulatory non-invasive brain stimulation technique, has shown promising results in basic and clinical studies. The known interindividual variability of the effects, however, limits the efficacy of the technique. Recently we reported neurophysiological effects of tDCS applied over th...
Chapter
Full-text available
Transcranial current stimulation (tCS or tES) protocols yield results that are highly variable across individuals. Part of this variability results from differences in the electric field (E-field) induced in subjects’ brains during stimulation. The E-field determines how neurons respond to stimulation, and it can be used as a proxy for predicting t...
Article
In refractory epilepsy, transcranial direct electrical stimulation (tDCS) is applied to decrease cortical activity with two (conventional tDCS) or several electrodes (multifocal tDCS). We investigated effects of personalized multisession, SEEG-targeted multifocal tDCS on seizure frequency (SF) and scalp functional connectivity (Fc) as measured by E...
Article
Full-text available
Introduction: Frontotemporal dementia (FTD) is a neurodegenerative disorder for which there is no effective pharmacological treatment. Recently, interneuron activity responsible for fast oscillatory brain activity has been found to be impaired in a mouse model of FTD with consequent cognitive and behavioral alterations. In this study, we aim to in...
Preprint
Full-text available
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...
Chapter
Reflectometry is one of many new applications made possible by freely available global navigation satellite system (GNSS) signals. Reflectometry measurement geometry has some features that are significantly different from conventional radar or radiometry. To understand the potential utility of GNSS reflectometry (GNSS‐R), first this chapter reviews...
Article
Background Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder associated with significant morbidity and mortality that may affect over 5% of children and approximately 2.8% of adults worldwide. Pharmacological and behavioral therapies exist, but critical symptoms such as dysexecutive deficits remain unaffected. In a ra...
Article
As NASA prepares for longer space missions aiming for the Moon and Mars, astronauts' health and performance are becoming a central concern due to the threats associated with galactic cosmic radiation, unnatural gravity fields, and life in extreme environments. In space, the human brain undergoes functional and structural changes related to fluid sh...
Article
Full-text available
Anodal transcranial direct current stimulation (tDCS), applied over the left dorsolateral prefrontal cortex (lDLPFC), can produce significant effects on working memory (WM) performance and associated neurophysiological activity. However, results from previous studies are inconsistent and occasionally contradictory. This inconsistency may be attribu...
Article
Full-text available
Background: Transcranial direct current stimulation (tDCS) may promote the recovery of severely brain-injured patients with disorders of consciousness (DOC). Prior tDCS studies targeted single brain regions rather than brain networks critical for consciousness recovery. Objective: Investigate the behavioral and electrophysiological effects of mu...
Chapter
The brain is a complex, plastic, electrical network where dysfunctions result in neurological disorders. Transcranial electrical stimulation (tES or tCS, as often abbreviated) is a noninvasive neuromodulatory technique with the potential for network-oriented therapy. The creation of multichannel systems has delivered unprecedented control over the...
Article
Dynamics within and between functional resting‐state networks have a crucial role in determining both healthy and pathological brain functioning in humans. The possibility to noninvasively interact and selectively modulate the activity of networks would open to relevant applications in neuroscience. Here we tested a novel approach for multichannel,...
Article
Objective Cathodal direct current stimulation (cDCS) induces long‐term depression (LTD)‐like reduction of cortical excitability (DCS‐LTD), which has been tested in the treatment of epilepsy with modest effects. In part, this may be due to variable cortical neuron orientation relative to the electric field. We tested, in vivo and in vitro , whether...
Article
Full-text available
Little is known about how transcranial alternating current stimulation (tACS) interacts with brain activity. Here, we investigate the effects of tACS using an intermittent tACS-EEG protocol and use, in addition to classical metrics, Lempel–Ziv–Welch complexity (LZW) to characterize the interactions between task, endogenous and exogenous oscillation...
Article
Full-text available
Several decades of research suggest that weak electric fields may influence neural processing, including those induced by neuronal activity and proposed as a substrate for a potential new cellular communication system, i.e., ephaptic transmission. Here we aim to model mesoscopic ephaptic activity in the human brain and explore its trajectory during...