Elaboration d'une méthodologie d'instrumentation pédagogique en contexte universitaire,

National audienceNous proposons dans cet article les premières étapes de l'établissement d'un canevas méthodologique permettant d'assister les acteurs de l'instrumentation de situations pédagogiques à l'aide d'outils reposant sur des technologies innovantes. Afin d'atteindre cet objectif, il a été entrepris une modélisation des différentes parties prenantes ainsi que l'environnement dans lequel s'inscrit cette instrumentation, dans ses dimensions organisationnelles et matérielles. Nous présentons le contexte de la genèse de ce modèle : l'instrumentation par un environnement outillé basé sur la transcription de la parole en direct, ainsi que d'autres technologies à l'état de prototypes de recherche. Abstract. This article presents the first steps in building a methodological framework aiming to assist contributors instrumenting pedagogical situations using tools based on innovative technologies. This framework ought to be used in various possible situations. This variety is described by a model of various stakeholders and the environment where the process is taking place, considering organizational or equipment constraints. Furthermore, we present the context leading to the creation of this model: instrumentation using a toolset based on synchronous speech transcription among other technologies in the research prototype stage

Front Aging Neurosci

We studied the influence of emotions on autobiographical memory (AbM) in patients with Alzheimer's disease (AD), characteristically triggering atrophy in the hippocampus and the amygdala, two crucial structures sustaining memory and emotional processing. Our first aim was to analyze the influence of emotion on AbM in AD patients, on both the proportion and the specificity of emotional memories. Additionally, we sought to determine the relationship of emotional AbM to amygdalar-hippocampal volumes. Eighteen prodromal to mild AD patients and 18 age-matched healthy controls were included. We obtained 30 autobiographical memories per participant using the modified Crovitz test (MCT). Analyses were performed on global scores, rates and specificity scores of the emotional vs. neutral categories of memories. Amygdalar-hippocampal volumes were extracted from 3D T1-weighted MRI scans and tested for correlations with behavioral data. Overall, AD patients displayed a deficit in emotional AbMs as they elicited less emotional memories than the controls, however, the specificity of those memories was preserved. The deficit likely implied retrieval or storage as it was extended in time and without reminiscence bump effect. Global scores and rates of emotional memories, but not the specificity scores, were correlated to right amygdalar and hippocampal volumes, indicating that atrophy in these structures has a central role in the deficit observed. Conversely, emotional memories were more specific than neutral memories in both groups, reflecting an enhancement effect of emotion that could be supported by other brain regions that are spared during the early stages of the disease

Neural correlates of visual hallucinations in dementia with Lewy bodies.

NTRODUCTION: The aim of this study was to investigate the association between visual hallucinations in dementia with Lewy bodies (DLB) and brain perfusion using single-photon emission computed tomography. METHODS: We retrospectively included 66 patients with DLB, 36 of whom were having visual hallucinations (DLB-hallu) and 30 of whom were not (DLB-c). We assessed visual hallucination severity on a 3-point scale of increasing severity: illusions, simple visual hallucinations and complex visual hallucinations. We performed voxel-level comparisons between the two groups and assessed correlations between perfusion and visual hallucinations severity. RESULTS: We found a significant decrease in perfusion in the left anterior cingulate cortex, the left orbitofrontal cortex and the left cuneus in the DLB-hallu group compared with the DLB-c group. We also found a significant correlation between decreased bilateral anterior cingulate cortex, left orbitofrontal cortex, right parahippocampal gyrus, right inferior temporal cortex and left cuneus perfusion with the severity of hallucinations. CONCLUSIONS: Visual hallucinations seem to be associated with the impairment of anterior and posterior regions (secondary visual areas, orbitofrontal cortex and anterior cingulate cortex) involved in a top-down and bottom-up mechanism, respectively. Furthermore, involvement of the bilateral anterior cingulate cortex and right parahippocampal gyrus seems to lead to more complex hallucinations.journal article20152015 02 17importe

Elaboration d'une méthodologie d'instrumentation pédagogique en contexte universitaire,

National audienceNous proposons dans cet article les premières étapes de l'établissement d'un canevas méthodologique permettant d'assister les acteurs de l'instrumentation de situations pédagogiques à l'aide d'outils reposant sur des technologies innovantes. Afin d'atteindre cet objectif, il a été entrepris une modélisation des différentes parties prenantes ainsi que l'environnement dans lequel s'inscrit cette instrumentation, dans ses dimensions organisationnelles et matérielles. Nous présentons le contexte de la genèse de ce modèle : l'instrumentation par un environnement outillé basé sur la transcription de la parole en direct, ainsi que d'autres technologies à l'état de prototypes de recherche. Abstract. This article presents the first steps in building a methodological framework aiming to assist contributors instrumenting pedagogical situations using tools based on innovative technologies. This framework ought to be used in various possible situations. This variety is described by a model of various stakeholders and the environment where the process is taking place, considering organizational or equipment constraints. Furthermore, we present the context leading to the creation of this model: instrumentation using a toolset based on synchronous speech transcription among other technologies in the research prototype stage

C3b complexation diversifies naturally processed T cell epitopes.

International audienceIn addition to its well-established role in innate immunity, the complement component C3 is of critical importance in modulating the humoral response. In this study, we examined the effect of C3b linkage to tetanus toxin (TeNT) in the production of antigenic peptides inside human APC. We purified HLA-DR associated peptides isolated either from TeNT or TeNT-C3b pulsed cells. This study revealed that TeNT-C3b derived antigenic peptides are different and more numerous than TeNT derived peptides. This increased production of antigenic peptides correlated with a C3b-induced TeNT modification of proteolysis. These findings argue in favour of a new role for C3b in the modulation of T cell epitope during antigen processing and presentation

Henry, where have you lost your Self?

The Self is a complex construct encompassing distinct components, including episodic and semantic autobiographical memory, the Self-concept, and the subjective sense of Self, which highest level consists of Self-awareness. The neuro-anatomical correlates are complex, and it is debated as to whether a common region could support these different components of the Self, with a particular interest for the cortical midline structures and the medial prefrontal cortex (MPFC). Alzheimer's disease (AD) constitutes an interesting model for the study of Self as autobiographical memory typically deteriorates as the disease progresses. Here, we report the unexpected case of Henry, a patient with MCI due to AD who was unable to produce any personal autobiographical memories, nor describe his Self-concept, had a poor personal semantic memory, and disclosed unusual anosognosia for this stage of the disease. His cognitive performance was compared to a group of matched AD patients and a group of healthy controls confirming that the main components of his Self were degraded. We hypothesized that it was due to a marked atrophy within the cortical midline, as visually assessed on his MRI. We further elucidated these findings through Voxel-based morphometry analysis, which confirmed a significant atrophy of the MPFC that was specific to this patient. Moreover, this revealed significant atrophy within the bilateral insular cortex. Given the stage of the disease, the degradation of the Self is unlikely to be accounted for by deficient mnemonic processes, especially as the presence of discrete temporal atrophy was noted. We suggest that this specific pattern of MPFC and insular atrophy is responsible for the systematic collapse of the patient's Self, through the breakdown of the subjective sense of Self, which is proposed as a prerequisite to all other components, according to the model proposed by Prebble, Addis, and Tippett (2013)

Different Temporal Patterns of Specific and General Autobiographical Memories across the Lifespan in Alzheimer’s Disease

We compared specific (i.e., associated with a unique time and space) and general (i.e., extended or repeated events) autobiographical memories (AbM) in Alzheimer’s disease (AD). The comparison aims at investigating the relationship between these two components of AbM across the lifespan and the volume of cerebral regions of interest within the temporal lobe. We hypothesized that the ability to elicit specific memories would correlate with hippocampal volume, whereas evoking general memories would be related to lateral temporal lobe. AbM was assessed using the modified Crovitz test in 18 patients with early AD and 18 matched controls. The proportions of total memories—supposed to reflect the ability to produce general memories—and specific memories retrieved were compared between AD patients and controls. Correlations to MRI volumes of temporal cortex were tested. We found different temporal patterns for specific and general memories in AD patients, with (i) relatively spared general memories, according to a temporal gradient that preserved remote memories, predominantly associated with right lateral temporal cortex volume. (ii) Conversely, the retrieval of specific AbMs was impaired for all life periods and correlated with bilateral hippocampal volumes. Our results highlight a shift from an initially episodic to a semantic nature of AbMs during AD, where the abstracted form of memories remains

MRI-based volumetry correlates of autobiographical memory in Alzheimer's disease.

The aim of the present volumetric study was to explore the neuro-anatomical correlates of autobiographical memory loss in Alzheimer's patients and healthy elderly, in terms of the delay of retention, with a particular interest in the medial temporal lobe structures. Fifteen patients in early stages of the disease and 11 matched control subjects were included in the study. To assess autobiographical memory and the effect of the retention delay, a modified version of the Crovitz test was used according to five periods of life. Autobiographical memory deficits were correlated to local atrophy via structural MRI using Voxel Based Morphometry. We used a 'lateralized index' to compare the relative contribution of hippocampal sub-regions (anterior vs posterior, left vs right) according to the different periods of life. Our results confirm the involvement of the hippocampus proper in autobiographical memory retrieval for both recent and very remote encoding periods, with larger aspect for the very remote period on the left side. Contrary to the prominent left-sided involvement for the young adulthood period, the implication of the right hippocampus prevails for the more recent periods and decreases with the remoteness of the memories, which might be associated with the visuo-spatial processing of the memories. Finally, we suggest the existence of a rostrocaudal gradient depending on the retention duration, with left anterior aspects specifically related to retrieval deficits of remote memories from the young adulthood period, whereas posterior aspects would result of simultaneous encoding and/or consolidation and retrieval deficit of more recent memories

Insular atrophy at the prodromal stage of dementia with Lewy bodies: a VBM DARTEL study

Abstract Diffuse atrophy including the insula was previously demonstrated in dementia with Lewy bodies (DLB) patients but little is known about the prodromal stage of DLB (pro-DLB). In this prospective study, we used SPM8-DARTEL to measure gray matter (GM) and white matter (WM) atrophy in pro-DLB patients (n = 54), prodromal Alzheimer’s disease (pro-AD) patients (n = 16), DLB patients at the stage of dementia (mild-DLB) (n = 15), and Alzheimer’s disease patients at the stage of dementia (mild-AD) (n = 28), and compared them with healthy elderly controls (HC, n = 22). Diminished GM volumes were found in bilateral insula in pro-DLB patients, a trend to significance in right hippocampus and parahippocampal gyrus in pro-AD patients, in left insula in mild-DLB patients, and in medial temporal lobes and insula in mild-AD patients. The comparison between prodromal groups did not showed any differences. The comparison between groups with dementia revealed atrophy around the left middle temporal gyrus in mild-AD patients. Reduced WM volume was observed in mild-DLB in the pons. The insula seems to be a key region in DLB as early as the prodromal stage. MRI studies looking at perfusion, and functional and anatomical connectivity are now needed to better understand the role of this region in DLB

Brain Regions with Relative Hypometabolism (red) and Relative Gray Matter Atrophy (yellow) in Relation with Hallucinations.

<p>Relative hypometabolism of right inferior frontal gyrus, middle frontal gyrus (including orbital part), and insula (anterior part) (slices z = −8 to 28). Core regions correspond to the common part of relative hypometabolism and atrophy, including right inferior frontal gyrus and a part of right anterior insula. (For MRI and FDG PET, p<0.001, uncorrected, minimum cluster size = 25 voxels). Right is right.</p