The joint memory effect: challenging the selfish stigma in Huntington's disease?

The prevalent belief that individuals with Huntington's disease exhibit selfish behaviour, disregarding the thoughts, feelings and actions of others, has been challenged by patient organizations and clinical experts. To further investigate this issue and study whether participants with Huntington's disease can pay attention to others, a joint memory task was carried out in patients with Huntington's disease with and without a partner. This study involved 69 participants at an early stage of Huntington's disease and 56 healthy controls from the UK, France and Germany, who participated in the international Repair-HD multicentre study (NCT03119246).

Cognitive reserve involves decision making and is associated with left parietal and hippocampal hypertrophy in neurodegeneration.

Cognitive reserve is the ability to actively cope with brain deterioration and delay cognitive decline in neurodegenerative diseases. It operates by optimizing performance through differential recruitment of brain networks or alternative cognitive strategies. We investigated cognitive reserve using Huntington's disease (HD) as a genetic model of neurodegeneration to compare premanifest HD, manifest HD, and controls.

A case-study of language-specific executive disorder.

Executive control is recruited for language processing, particularly in complex linguistic tasks. Although the issue of the existence of an executive control specific to language is still an open issue, there is much evidence that executively-demanding language tasks rely on domain-general rather than language-specific executive resources. Here, we addressed this issue by assessing verbal and non-verbal executive capacities in LG, an aphasic patient after a stroke.

Striatum and language processing: Where do we stand?

More than a century ago, Broca (1861), Wernicke (1874) and Lichteim (1885) laid the foundations for the first anatomo-functional model of language, secondarily enriched by Geschwind (1967), leading to the Broca-Wernicke-Lichteim-Geschwind model. This model included the frontal, parietal, and temporal cortices as well as a subcortical structure, which could be the striatum, whose nature and role have remained unclear. Although the emergence of language deficits in patients with striatal injury has challenged the cortical language models developed over the past 30 years, the integration of the striatum into language processing models remains rare.

Striatal connectivity in pre-manifest Huntington's disease is differentially affected by disease burden.

Background And Purpose: Different amounts of cumulative exposure to the toxic mutant form of the huntingtin protein might underlie the distinctive pattern of striatal connectivity in pre-manifest Huntington's disease (pre-HD). The aim of this study was to investigate disease-burden-dependent cortical-striatal and subcortical-striatal loops at different pre-HD stages.

Methods: A total of 16 participants with pre-HD and 25 controls underwent magnetic resonance imaging to investigate striatal structural and functional connectivity (FC).

Cloaking by coating: how effectively does a thin, stiff coating hide a soft substrate?

From human tissue to fruits, many soft materials are coated by a thin layer of a stiffer material. While the primary role of such a coating is often to protect the softer material, the thin, stiff coating also has an important effect on the mechanical behaviour of the composite material, making it appear significantly stiffer than the underlying material. We study this cloaking effect of a coating for the particular case of indentation tests, which measure the 'firmness' of the composite solid: we use a combination of theory and experiment to characterize the firmness quantitatively.

Aberrant brain network connectivity in presymptomatic and manifest Huntington's disease: A systematic review.

Resting-state functional magnetic resonance imaging (rs-fMRI) has the potential to shed light on the pathophysiological mechanisms of Huntington's disease (HD), paving the way to new therapeutic interventions. A systematic literature review was conducted in three online databases according to PRISMA guidelines, using keywords for HD, functional connectivity, and rs-fMRI. We included studies investigating connectivity in presymptomatic (pre-HD) and manifest HD gene carriers compared to healthy controls, implementing seed-based connectivity, independent component analysis, regional property, and graph analysis approaches.

Improving language evaluation in neurological disorders: The French Core Assessment of Language Processing (CALAP).

Aphasia is a devastating brain disorder, detrimental for medical care and social interaction. The early diagnosis of language disorders and accurate identification of patient-specific deficits are crucial for patients' care, as aphasia rehabilitation is more effective when focused on patient-specific language deficits. We developed the Core Assessment of Language Processing (CALAP), a new scale combining screening and detailed evaluation to rapidly diagnose and identify patient-specific language deficits.

Structural priming in sentence comprehension: A single prime is enough.

Experiencing a syntactic structure affects how we process subsequent instances of that structure. This phenomenon, called structural priming, is observed both in language production and in language comprehension. However, while abstract syntactic structures can be primed independent of lexical overlap in sentence production, evidence for structural priming in comprehension is more elusive.

COMT Val158Met Polymorphism Modulates Huntington's Disease Progression.

Little is known about the genetic factors modulating the progression of Huntington's disease (HD). Dopamine levels are affected in HD and modulate executive functions, the main cognitive disorder of HD. We investigated whether the Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene, which influences dopamine (DA) degradation, affects clinical progression in HD.

Pointing to others: How the target gender influences pointing performance.

Pointing is a communicative gesture that allows individuals to share information about surrounding objects with other humans. Patients with heterotopagnosia are specifically impaired in pointing to other humans' body parts but not in pointing to themselves or to objects. Here, we describe a female patient with heterotopagnosia who was more accurate in pointing to men's body parts than to women's body parts.

Complex linguistic rules modulate early auditory brain responses.

During speech perception, listeners compensate for phonological rules of their language. For instance, English place assimilation causes green boat to be typically pronounced as greem boat; English listeners, however, perceptually compensate for this rule and retrieve the intended sound (n). Previous research using EEG has focused on rules with clear phonetic underpinnings, showing that perceptual compensation occurs at an early stage of speech perception.

The second person in "I"-"you"-"it" triadic interactions.

Second person social cognition cannot be restricted to dyadic interactions between two persons (the "I" and the "you"). Many instances of social communication are triadic, and involve a third person (the "him/her/it"), which is the object of the interaction. We discuss neuropsychological and brain imaging data showing that triadic interactions involve dedicated brain networks distinct from those of dyadic interactions.

Awareness of memory deficits in early stage Huntington's disease.

Patients with Huntington's disease (HD) are often described as unaware of their motor symptoms, their behavioral disorders or their cognitive deficits, including memory. Nevertheless, because patients with Parkinson's disease (PD) remain aware of their memory deficits despite striatal dysfunction, we hypothesize that early stage HD patients in whom degeneration predominates in the striatum can accurately judge their own memory disorders whereas more advanced patients cannot. In order to test our hypothesis, we compared subjective questionnaires of memory deficits (in HD patients and in their proxies) and objective measures of memory dysfunction in patients.

Specificity in rehabilitation of word production: a meta-analysis and a case study.

Speech production impairment is a frequent deficit observed in aphasic patients and rehabilitation programs have been extensively developed. Nevertheless, there is still no agreement on the type of rehabilitation that yields the most successful outcomes. Here, we ran a detailed meta-analysis of 39 studies of word production rehabilitation involving 124 patients.

Is the word-length effect linked to subvocal rehearsal?

Models of phonological short-term memory (pSTM) generally distinguish between two components: a phonological buffer and a subvocal rehearsal. Evidence for these two components comes, respectively, from the phonological similarity effect and the word-length effect which disappears under articulatory suppression. But alternative theories posit that subvocal rehearsal is only an optional component of the pSTM.

Breaking the mirror: Asymmetrical disconnection between the phonological input and output codes.

In this paper, we study the link between the processing systems that sustain speech perception and production in a patient (F.A.) with conduction aphasia.

What is the relationship between phonological short-term memory and speech processing?

Traditionally, models of speech comprehension and production do not depend on concepts and processes from the phonological short-term memory (pSTM) literature. Likewise, in working memory research, pSTM is considered to be a language-independent system that facilitates language acquisition rather than speech processing per se. We discuss couplings between pSTM, speech perception and speech production, and we propose that pSTM arises from the cycling of information between two phonological buffers, one involved in speech perception and one in speech production.

Misperception in sentences but not in words: Speech perception and the phonological buffer.

We report two case studies of aphasic patients with a working-memory impairment due to reduced storage in the phonological buffer. The two patients display excellent performance in phonological discrimination tasks as long as the tasks do not involve a memory load. We then show that their performance drops when they have to maintain fine-grained phonological information for sentence comprehension: They are impaired at mispronunciation detection and at comprehending sentences involving minimal word pairs.

Processing of the bovine spongiform encephalopathy-specific prion protein by dendritic cells.

Dendritic cells (DC) are suspected to be involved in transmissible spongiform encephalopathies, including bovine spongiform encephalopathy (BSE). We detected the disease-specific, protease-resistant prion protein (PrP(bse)) in splenic DC purified by magnetic cell sorting 45 days after intraperitoneal inoculation of BSE prions in immunocompetent mice. We showed that bone marrow-derived DC (BMDC) from wild-type or PrP-null mice acquired both PrP(bse) and prion infectivity within 2 h of in vitro culture with a BSE inoculum.

High incidence of scrapie induced by repeated injections of subinfectious prion doses.

To clarify the mechanisms leading to the development of Creutzfeldt-Jakob disease in some recipients of pituitary-derived human growth hormone (hGH), we investigated the effects of repeated injections of low prion doses in mice. The injections were performed, as in hGH-treated children, by a peripheral route at short intervals and for an extended period. Twelve groups of 24 mice were intraperitoneally inoculated one, two, or five times per week for 200 days with 2 x 10(-5) to 2 x 10(-8) dilutions of brain homogenate containing the mouse-adapted C506M3 scrapie strain.

Human immunodeficiency virus 1 favors the persistence of infection by activating macrophages through TNF.

Macrophages play a major role in HIV-1 persistence. In the present paper, we demonstrate that the absence of apoptosis in HIV-1-infected primary human monocyte-differentiated macrophages (MDM) correlates with an increase in anti-apoptotic (Bcl-2 and Bcl-x(L)) and a decrease in pro-apoptotic (Bax and Bad) proteins. This is associated with macrophage activation as shown by tumor necrosis factor (TNF) production and NF-kappaB activation upon infection.