Orthographic Contamination of Broca’s Area

Strong evidence has accumulated over the past years suggesting that orthography plays a role in spoken language processing. It is still unclear, however, whether the influence of orthography on spoken language results from a co-activation of posterior brain areas dedicated to low-level orthographic processing or whether it results from orthographic restructuring of phonological representations located in the anterior perisylvian speech network itself. To test these hypotheses, we ran a fMRI study that tapped orthographic processing in the visual and auditory modalities. As a marker for orthographic processing, we used the orthographic decision task in the visual modality and the orthographic consistency effect in the auditory modality. Results showed no specific orthographic activation neither for the visual nor the auditory modality in left posterior occipito-temporal brain areas that are thought to host the visual word form system. In contrast, specific orthographic activation was found both for the visual and auditory modalities at anterior sites belonging to the perisylvian region: the left dorsal–anterior insula and the left inferior frontal gyrus. These results are in favor of the restructuring hypothesis according to which learning to read acts like a “virus” that permanently contaminates the spoken language system

Human Retinotopic Mapping Using fMRI

We present in this report a new method for the retinotopic mapping of the human visual cortex using fMRI. This fast method allow s to delineate any human's occipital retinotopic visual areas after 30 minutes in an MR scanner. Based on the known retinotopic properties o f the visual cortex and on the procedures described in the literature, we first detail the experimental protocol we used. We then present th e functional data analysis we perform to get the retinotopic angular maps. The algorithm to get a model of the cortical surface from the ana tomical MR image is also rapidly presented. We then show the retinotopic maps projected on the latter model and compare them with the litera ture. Lastly, we present the choices we made to delineate these areas and extract regions of interest that can be used for further studying the human visual cortical system

Left ventricular heart failure and pulmonary hypertension

In patients with left ventricular heart failure (HF), the development of pulmonary hypertension (PH) and right ventricular (RV) dysfunction are frequent and have important impact on disease progression, morbidity, and mortality, and therefore warrant clinical attention. Pulmonary hypertension related to left heart disease (LHD) by far represents the most common form of PH, accounting for 65–80% of cases. The proper distinction between pulmonary arterial hypertension and PH-LHD may be challenging, yet it has direct therapeutic consequences. Despite recent advances in the pathophysiological understanding and clinical assessment, and adjustments in the haemodynamic definitions and classification of PH-LHD, the haemodynamic interrelations in combined post- and pre-capillary PH are complex, definitions and prognostic significance of haemodynamic variables characterizing the degree of pre-capillary PH in LHD remain suboptimal, and there are currently no evidence-based recommendations for the management of PH-LHD. Here, we highlight the prevalence and significance of PH and RV dysfunction in patients with both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF), and provide insights into the complex pathophysiology of cardiopulmonary interaction in LHD, which may lead to the evolution from a ‘left ventricular phenotype’ to a ‘right ventricular phenotype’ across the natural history of HF. Furthermore, we propose to better define the individual phenotype of PH by integrating the clinical context, non-invasive assessment, and invasive haemodynamic variables in a structured diagnostic work-up. Finally, we challenge current definitions and diagnostic short falls, and discuss gaps in evidence, therapeutic options and the necessity for future developments in this context

Recruitment of Both the Mirror and the Mentalizing Networks When Observing Social Interactions Depicted by Point-Lights: A Neuroimaging Study

Background: Understanding social interactions requires the ability to accurately interpret conspecifics ’ actions, sometimes only on the basis of subtle body language analysis. Here we address an important issue that has not yet received much attention in social neuroscience, that of an interaction between two agents. We attempted to isolate brain responses to two individuals interacting compared to two individuals acting independently. Methodology/Principal Findings: We used minimalistic point-light displays to depict the characters, as they provide the most straightforward way to isolate mechanisms used to extract information from motion per se without any interference with other visual information. Functional magnetic resonance imaging (fMRI) method was used to determine which brain regions were recruited during the observation of two interacting agents, mimicking everyday social scenes. While the mirror and mentalizing networks are rarely concurrently active, we found that both of them might be needed to catch the social intentions carried by whole-body motion. Conclusions/Significance: These findings shed light on how motor cognition contributes to social cognition when social information is embedded in whole-body motion only. Finally, the approach described here provides a valuable and origina

Taste at first (person) sight: visual perspective modulates brain activity implicitly associated with viewing unhealthy but not healthy foods

Every day, people are exposed to images of appetizing foods that can lead to high-calorie intake and contribute to overweight and obesity. Research has documented that manipulating the visual perspective from which eating is viewed helps resist temptation by altering the appraisal of unhealthy foods. However, the neural basis of this effect has not yet been examined using neuroimaging methods. Moreover, it is not known whether the benefits of this strategy can be observed when people, especially overweight, are not explicitly asked to imagine themselves eating. Last, it remains to be investigated if visual perspective could be used to promote healthy foods. The present work manipulated camera angles and tested whether visual perspective modulates activity in brain regions associated with taste and reward processing while participants watch videos featuring a hand grasping (unhealthy or healthy) foods from a plate during functional magnetic resonance imagining (fMRI). The plate was filmed from the perspective of the participant (first-person perspective; 1PP), or from a frontal view as if watching someone else eating (third-person perspective; 3PP). Our findings reveal that merely viewing unhealthy food cues from a 1PP (vs. 3PP) increases activity in brain regions that underlie representations of rewarding (appetitive) experiences (amygdala) and food intake (superior parietal gyrus). Additionally, our results show that ventral striatal activity is positively correlated with body mass index (BMI) during exposure to unhealthy foods from a 1PP (vs. 3PP). These findings suggest that unhealthy foods should be promoted through third-person (video) images to weaken the reward associated with their simulated consumption, especially amongst overweight people. It appears however that, as such, manipulating visual perspective fails to enhance the perception of healthy foods. Their promotion thus requires complementary solutions

Tariff optimization in Networks

We consider the problem of determining a set of optimal tariffs for an agent in the network, who owns a subset of all the arcs, and who receives revenue by setting the tariffs on the arc he owns. Multiple rational clients are active in the network, who route their demands on the cheapest paths from source to destination. The cost of a path is determined by fixed costs and tariffs on the arcs of the path.We introduce a remodeling of the network, using shortest paths. We develop three algorithms, a path oriented mixed integer program and a known arc oriented mixed integer program. Combined with reduction methods this remodeling enables us to solve the problem to optimality, for quite large instances. We provide computational results for the methods developped and compare them with the results of the arc oriented mixed integer programming formulation of the problem, applied to the original network.Economics ;

Perception de la parole et IRM : réalisation, évaluation et validation d'un système permettant une stimulation sonore de qualité en cours de séquence IRM

International audienceThis study describes the design and the assessment of a MRI-compatible sound production hardware. This system was developed to permit auditory studies with Magnetic Resonance Imaging (MRI) techniques. An important disadvantage caused by the MR imager is the acoustic noise generated during data acquisition, due to the fast gradient switching interacting with the main magnetic field. Several solutions were explored to reduce noise and to provide audio stimuli with a reasonable quality. The sound production system was first tested by instrumental methods (sound level, spectral analysis). Finally, perceptual tests consisting in intelligibility, semantic decision and prosodic judgement were achieved to validate the installation.Cette étude décrit la réalisation d'un dispositif de stimulation auditive pour un imageur à résonnance magnétique fonctionelle de 3 Tesla. Le plus important probléme de ces systémes réside dans l'émission d'un niveau de bruit considérable au cours de son fonctionnement qui les rend quasi impossible à utiliser pour des études en stimulation auditive.Plusieurs solutions de stimulation de réalisation locale sont proposées pour permettre de gérérer au tympan des sujet une stimulation de qualité raisonnable. Les stimulus ainsi générés sont d'abord testés au moyen de méthodes physiques classiques (analyses acoustiques). Ils sont ensuite testés au moyen de tests d'intelligibilité de décision sémantique et de jugement prosodique afin de les valider pour des études de psycho linguistique et psycho acoustique

Why people drink shampoo? Food imitating products are fooling brains and endangering consumers for marketing purposes

A Food Imitating Product (FIP) is a household cleaner or a personal care product that exhibits food attributes in order to enrich consumption experience. As revealed by many cases worldwide, such a marketing strategy led to unintentional self-poisonings and deaths. FIPs therefore constitute a very serious health and public policy issue. To understand why FIPs are a threat, we first conducted a qualitative analysis on real-life cases of household cleaners and personal care products-related phone calls at a poison control center followed by a behavioral experiment. Unintentional self-poisoning in the home following the accidental ingestion of a hygiene product by a healthy adult is very likely to result from these products being packaged like foodstuffs. Our hypothesis is that FIPs are non-verbal food metaphors that could fool the brain of consumers. We therefore conducted a subsequent functional neuroimaging (fMRI) experiment that revealed how visual processing of FIPs leads to cortical taste inferences. Considered in the grounded cognition perspective, the results of our studies reveal that healthy adults can unintentionally categorize a personal care product as something edible when a food-like package is employed to market nonedible and/or dangerous products. Our methodology combining field (qualitative) and laboratory (behavioral and functional neuroimaging) findings could be of particular relevance for policy makers, as it can help screening products prior to their market release – e.g. the way they are packaged and how they can potentially confuse the mind of consumers – and therefore save lives

Human Retinotopic Mapping Using fMRI

We present in this report a new method for the retinotopic mapping of the human visual cortex using fMRI. This fast method allow s to delineate any human's occipital retinotopic visual areas after 30 minutes in an MR scanner. Based on the known retinotopic properties o f the visual cortex and on the procedures described in the literature, we first detail the experimental protocol we used. We then present th e functional data analysis we perform to get the retinotopic angular maps. The algorithm to get a model of the cortical surface from the ana tomical MR image is also rapidly presented. We then show the retinotopic maps projected on the latter model and compare them with the litera ture. Lastly, we present the choices we made to delineate these areas and extract regions of interest that can be used for further studying the human visual cortical system