3D model fitting for facial expression analysis under uncontrolled imaging conditions

International audienceThis paper addresses the recovering of 3D pose and animation of the human face in a monocular single image under uncontrolled imaging conditions. Our goal is to fit a 3D animated model in a face image with possibly large variations of head pose and facial expressions. Our data were acquired from filmed epileptic seizures of patients undergoing investigation in the videotelemetry 1unit, La Timone hospital, Marseille, France

Neural mass activity, bifurcations, and epilepsy.

International audienceIn this letter, we propose a general framework for studying neural mass models defined by ordinary differential equations. By studying the bifurcations of the solutions to these equations and their sensitivity to noise, we establish an important relation, similar to a dictionary, between their behaviors and normal and pathological, especially epileptic, cortical patterns of activity. We then apply this framework to the analysis of two models that feature most phenomena of interest, the Jansen and Rit model, and the slightly more complex model recently proposed by Wendling and Chauvel. This model-based approach allows us to test various neurophysiological hypotheses on the origin of pathological cortical behaviors and investigate the effect of medication. We also study the effects of the stochastic nature of the inputs, which gives us clues about the origins of such important phenomena as interictal spikes, interictal bursts, and fast onset activity that are of particular relevance in epilepsy

Improving stress echocardiography accuracy for detecting left circumflex artery stenosis: A new echocardiographic sign?

SummaryBackgroundThe accuracy and reproducibility of stress echocardiography (SE) for the detection of coronary artery lesions requires improvement, particularly in the left circumflex artery (LCx).AimsTo evaluate the feasibility and diagnostic value of a new sign: Rise of the Apical lateral wall and/or Horizontal displacement of the Apex toward the septum (“RA-HA”) in apical echocardiographic views.MethodsConsecutive patients with normal left ventricular function at rest, positive SE and an indication for coronary angiography were included. SEs were analysed blindly by three independent cardiologists: two seniors (S1 and S2) and one junior (J).ResultsOf 81 patients, 58 had an exercise SE and 23 had a dobutamine SE. Significant coronary stenosis was found in 59 of 77 patients who underwent coronary angiography (76.6%). Interobserver reproducibility for the presence of RA-HA was very good between S1 and S2 (κ=0.86), and good between S1 and J (0.67) and S2 and J (0.70). The sensitivity, specificity and positive and negative predictive values of RA-HA for the detection of significant coronary artery stenosis were, respectively, 39–41%, 83–89%, 88–92% and 29–31% for S1/S2; and 29%, 83%, 85% and 26% for J. To predict LCx stenosis (single or multivessel): 67–70%, 89%, 80–81% and 80–82% for S1/S2, respectively, and 50%, 89%, 75% and 74% for J.ConclusionWith a short learning curve, RA-HA is easily diagnosed with a very good interobserver reproducibility. It has high specificity and PPV for the detection of a coronary artery stenosis, particularly in the LCx artery, during exercise or dobutamine SE

Interictal Functional Connectivity of Human Epileptic Networks Assessed by Intracerebral EEG and BOLD Signal Fluctuations

In this study, we aimed to demonstrate whether spontaneous fluctuations in the blood oxygen level dependent (BOLD) signal derived from resting state functional magnetic resonance imaging (fMRI) reflect spontaneous neuronal activity in pathological brain regions as well as in regions spared by epileptiform discharges. This is a crucial issue as coherent fluctuations of fMRI signals between remote brain areas are now widely used to define functional connectivity in physiology and in pathophysiology. We quantified functional connectivity using non-linear measures of cross-correlation between signals obtained from intracerebral EEG (iEEG) and resting-state functional MRI (fMRI) in 5 patients suffering from intractable temporal lobe epilepsy (TLE). Functional connectivity was quantified with both modalities in areas exhibiting different electrophysiological states (epileptic and non affected regions) during the interictal period. Functional connectivity as measured from the iEEG signal was higher in regions affected by electrical epileptiform abnormalities relative to non-affected areas, whereas an opposite pattern was found for functional connectivity measured from the BOLD signal. Significant negative correlations were found between the functional connectivities of iEEG and BOLD signal when considering all pairs of signals (theta, alpha, beta and broadband) and when considering pairs of signals in regions spared by epileptiform discharges (in broadband signal). This suggests differential effects of epileptic phenomena on electrophysiological and hemodynamic signals and/or an alteration of the neurovascular coupling secondary to pathological plasticity in TLE even in regions spared by epileptiform discharges. In addition, indices of directionality calculated from both modalities were consistent showing that the epileptogenic regions exert a significant influence onto the non epileptic areas during the interictal period. This study shows that functional connectivity measured by iEEG and BOLD signals give complementary but sometimes inconsistent information in TLE

The Good Wife? Sibling Species in Han Kang's The Vegetarian

Winner of the 2016 Man Booker International Prize, Han Kang’s The Vegetarian (translated into English by Deborah Smith in 2015) troubles postcolonial intersections of sex, contagion and culinary habits by following the vegan transition of a woman named Yeong-hye in South Korea. In this article, I argue that Yeong-hye’s posthumanist performance of vegan praxis is motivated not by illogical illness, but rather by unutterable trauma and the struggle for intersectional power. Specifically, I focus on exchanges between ‘sibling species’, considering how transgressive animal, corporeal and sexual imagery is used to reimagine both ethical positions and interpersonal relationships

Sensitivity of the human auditory cortex to acoustic degradation of speech and non-speech sounds

The perception of speech is usually an effortless and reliable process even in highly adverse listening conditions. In addition to external sound sources, the intelligibility of speech can be reduced by degradation of the structure of speech signal itself, for example by digital compression of sound. This kind of distortion may be even more detrimental to speech intelligibility than external distortion, given that the auditory system will not be able to utilize sound source-specific acoustic features, such as spatial location, to separate the distortion from the speech signal. The perceptual consequences of acoustic distortions on speech intelligibility have been extensively studied. However, the cortical mechanisms of speech perception in adverse listening conditions are not well known at present, particularly in situations where the speech signal itself is distorted. The aim of this thesis was to investigate the cortical mechanisms underlying speech perception in conditions where speech is less intelligible due to external distortion or as a result of digital compression. In the studies of this thesis, the intelligibility of speech was varied either by digital compression or addition of stochastic noise. Cortical activity related to the speech stimuli was measured using magnetoencephalography (MEG). The results indicated that degradation of speech sounds by digital compression enhanced the evoked responses originating from the auditory cortex, whereas addition of stochastic noise did not modulate the cortical responses. Furthermore, it was shown that if the distortion was presented continuously in the background, the transient activity of auditory cortex was delayed. On the perceptual level, digital compression reduced the comprehensibility of speech more than additive stochastic noise. In addition, it was also demonstrated that prior knowledge of speech content enhanced the intelligibility of distorted speech substantially, and this perceptual change was associated with an increase in cortical activity within several regions adjacent to auditory cortex. In conclusion, the results of this thesis show that the auditory cortex is very sensitive to the acoustic features of the distortion, while at later processing stages, several cortical areas reflect the intelligibility of speech. These findings suggest that the auditory system rapidly adapts to the variability of the auditory environment, and can efficiently utilize previous knowledge of speech content in deciphering acoustically degraded speech signals.Puheen havaitseminen on useimmiten vaivatonta ja luotettavaa myös erittäin huonoissa kuunteluolosuhteissa. Puheen ymmärrettävyys voi kuitenkin heikentyä ympäristön häiriölähteiden lisäksi myös silloin, kun puhesignaalin rakennetta muutetaan esimerkiksi pakkaamalla digitaalista ääntä. Tällainen häiriö voi heikentää ymmärrettävyyttä jopa ulkoisia häiriöitä voimakkaammin, koska kuulojärjestelmä ei pysty hyödyntämään äänilähteen ominaisuuksia, kuten äänen tulosuuntaa, häiriön erottelemisessa puheesta. Akustisten häiriöiden vaikutuksia puheen havaitsemiseen on tutkttu laajalti, mutta havaitsemiseen liittyvät aivomekanismit tunnetaan edelleen melko puutteelisesti etenkin tilanteissa, joissa itse puhesignaali on laadultaan heikentynyt. Tämän väitöskirjan tavoitteena oli tutkia puheen havaitsemisen aivomekanismeja tilanteissa, joissa puhesignaali on vaikeammin ymmärrettävissä joko ulkoisen äänilähteen tai digitaalisen pakkauksen vuoksi. Väitöskirjan neljässä osatutkimuksessa lyhyiden puheäänien ja jatkuvan puheen ymmärrettävyyttä muokattiin joko digitaalisen pakkauksen kautta tai lisäämällä puhesignaaliin satunnaiskohinaa. Puheärsykkeisiin liittyvää aivotoimintaa tutkittiin magnetoenkefalografia-mittauksilla. Tutkimuksissa havaittiin, että kuuloaivokuorella syntyneet herätevasteet voimistuivat, kun puheääntä pakattiin digitaalisesti. Sen sijaan puheääniin lisätty satunnaiskohina ei vaikuttanut herätevasteisiin. Edelleen, mikäli puheäänien taustalla esitettiin jatkuvaa häiriötä, kuuloaivokuoren aktivoituminen viivästyi häiriön intensiteetin kasvaessa. Kuuntelukokeissa havaittiin, että digitaalinen pakkaus heikentää puheäänien ymmärrettävyyttä voimakkaammin kuin satunnaiskohina. Lisäksi osoitettiin, että aiempi tieto puheen sisällöstä paransi merkittävästi häiriöisen puheen ymmärrettävyyttä, mikä heijastui aivotoimintaan kuuloaivokuoren viereisillä aivoalueilla siten, että ymmärrettävä puhe aiheutti suuremman aktivaation kuin heikosti ymmärrettävä puhe. Väitöskirjan tulokset osoittavat, että kuuloaivokuori on erittäin herkkä puheäänien akustisille häiriöille, ja myöhemmissä prosessoinnin vaiheissa useat kuuloaivokuoren viereiset aivoalueet heijastavat puheen ymmärrettävyyttä. Tulosten mukaan voi olettaa, että kuulojärjestelmä mukautuu nopeasti ääniympäristön vaihteluihin muun muassa hyödyntämällä aiempaa tietoa puheen sisällöstä tulkitessaan häiriöistä puhesignaalia

Highlights From the Annual Meeting of the American Epilepsy Society 2022

With more than 6000 attendees between in-person and virtual offerings, the American Epilepsy Society Meeting 2022 in Nashville, felt as busy as in prepandemic times. An ever-growing number of physicians, scientists, and allied health professionals gathered to learn a variety of topics about epilepsy. The program was carefully tailored to meet the needs of professionals with different interests and career stages. This article summarizes the different symposia presented at the meeting. Basic science lectures addressed the primary elements of seizure generation and pathophysiology of epilepsy in different disease states. Scientists congregated to learn about anti-seizure medications, mechanisms of action, and new tools to treat epilepsy including surgery and neurostimulation. Some symposia were also dedicated to discuss epilepsy comorbidities and practical issues regarding epilepsy care. An increasing number of patient advocates discussing their stories were intertwined within scientific activities. Many smaller group sessions targeted more specific topics to encourage member participation, including Special Interest Groups, Investigator, and Skills Workshops. Special lectures included the renown Hoyer and Lombroso, an ILAE/IBE joint session, a spotlight on the impact of Dobbs v. Jackson on reproductive health in epilepsy, and a joint session with the NAEC on coding and reimbursement policies. The hot topics symposium was focused on traumatic brain injury and post-traumatic epilepsy. A balanced collaboration with the industry allowed presentations of the latest pharmaceutical and engineering advances in satellite symposia

Bases neurophysiologiques de la mémoire de reconnaissance verbale et visuelle (étude des potentiels évoqués de surface et intra-cérébraux)

The main purpose of the current studies was to address the issue of hemispheric specialization during the multi-step process of recognition, taking into account the confounding factors of tasks (encoding vs. recognition) and processing stages. The first study of scalp evoked potentials in healthy volunteers allowed the identification of a negative wave, peaking around 270 ms. This N270 was evoked by both categorization and recognition tasks of words and abstract designs, was functionally and anatomically distinct from the N400 and was thought to reflect the processing stage of perceptivo-mnesic transition. The process reflected by the N270 was asymetric according to the material, was not modulated by the repetition effect, and was best modelled by spatially restricted generators localized in the rhinal cortex. In the second study, we used intra-cerebral evoked potentials and showed that activity recorded within ento and peri-rhinal cortices had distinct temporal dynamics, and distinct functional properties. Peri-rhinal activity was characterized by two successive potentials, the N230 and N400, modulated by a repetition-suppression effect. Ento-rhinal activity was characterized by a N250 potential, modulated by the material and by a repetition-enhancement effect which was also observed in hippocampus. These intra-cerebral data support the hypothesis that the scalp N270 would result from the summation of the peri-rhinal N230 and ento-rhinal N250. In the third study, we studied the reorganization of perceptivo-mnesic networks in patients with left or right temporal lobe epilepsy. Results suggests that this potential may be used as an index of residual functionality of medial temporal structures, ispilateral to the epileptogenic zone.L objectif de ce travail était d étudier avec les potentiels évoqués la question de la spécialisation hémisphérique au cours de la reconnaissance, en tenant compte de la tâche et surtout des différentes étapes qui jalonnent la transition perceptivo mnésique de la voie visuelle ventrale vers le lobe temporal médial. La première étude des potentiels évoqués de surface chez des volontaires sains a identifié une composante négative culminant autour de 270 ms (appelée N270) évoquée à la fois par la catégorisation et la reconnaissance des mots et des images abstraites, qui était fonctionnellement et anatomiquement distincte de la N400. La N270 reflétait un processus asymétrique en fonction du matériel, qui n était pas modulée par l effet de répétition et dont les générateurs étaient spatialement plus localisés (moins distribués) que ceux de la N400, avec une source majeure au niveau du cortex rhinal. Dans la seconde étude nous avons montré à partir d enregistrements intra cérébraux que les cortex ento et péri-rhinal se différenciaient par leur dynamique temporelle, et par des propriétés fonctionnelles distinctes. L activité du cortex péri-rhinal était caractérisée par deux potentiels successifs N230 puis N400 modulés par l effet de répétition-suppression. L activité du cortex ento-rhinal était caractérisée par un potentiel N250, modulé par la nature du matériel et par un effet de répétition-amplification qui était également observé dans l hippocampe. Ces données confortent l hypothèse selon laquelle la N270 de scalp résulte de la sommation des potentiels N230 péri-rhinal et N250 ento-rhinal. Enfin, dans la troisième étude, nous avons étudié la réorganisation des réseaux perceptivo-mnésiques induite par l épilepsie temporale en à l aide des potentiels évoqués de reconnaissance de surface. Nos résultats suggèrent que ce potentiel pourrait refléter la fonctionnalité résiduelle des structures temporales internes ipsilatérales à l épilepsie.AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocSudocFranceF

LOCALISATION ANATOMIQUE DES EVENEMENTS PAROXYSTIQUES INTERCRITIQUES GRACE A L'EEG HAUTE RESOLUTION CHEZ DES PATIENTS PRESENTANT UNE EPILEPSIE PARTIELLE PHARMACORESISTANTE (DES NEUROLOGIE)

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF