Impaired perception of biological motion in Parkinson’s disease

OBJECTIVE: We examined biological motion perception in Parkinson’s disease (PD). Biological motion perception is related to one’s own motor function and depends on the integrity of brain areas affected in PD, including posterior superior temporal sulcus. If deficits in biological motion perception exist, they may be specific to perceiving natural/fast walking patterns that individuals with PD can no longer perform, and may correlate with disease-related motor dysfunction. METHOD: Twenty-six nondemented individuals with PD and 24 control participants viewed videos of point-light walkers and scrambled versions that served as foils, and indicated whether each video depicted a human walking. Point-light walkers varied by gait type (natural, parkinsonian) and speed (0.5, 1.0, 1.5 m/s). Participants also completed control tasks (object motion, coherent motion perception), a contrast sensitivity assessment, and a walking assessment. RESULTS: The PD group demonstrated significantly less sensitivity to biological motion than the control group (p < .001, Cohen’s d = 1.22), regardless of stimulus gait type or speed, with a less substantial deficit in object motion perception (p = .02, Cohen’s d = .68). There was no group difference in coherent motion perception. Although individuals with PD had slower walking speed and shorter stride length than control participants, gait parameters did not correlate with biological motion perception. Contrast sensitivity and coherent motion perception also did not correlate with biological motion perception. CONCLUSION: PD leads to a deficit in perceiving biological motion, which is independent of gait dysfunction and low-level vision changes, and may therefore arise from difficulty perceptually integrating form and motion cues in posterior superior temporal sulcus.Published versio

Randomized controlled trial of a home-based action observation intervention to improve walking in Parkinson disease

Published in final edited form as: Arch Phys Med Rehabil. 2016 May ; 97(5): 665–673. doi:10.1016/j.apmr.2015.12.029.OBJECTIVE: To examine the feasibility and efficacy of a home-based gait observation intervention for improving walking in Parkinson disease (PD). DESIGN: Participants were randomly assigned to an intervention or control condition. A baseline walking assessment, a training period at home, and a posttraining assessment were conducted. SETTING: The laboratory and participants' home and community environments. PARTICIPANTS: Nondemented individuals with PD (N=23) experiencing walking difficulty. INTERVENTION: In the gait observation (intervention) condition, participants viewed videos of healthy and parkinsonian gait. In the landscape observation (control) condition, participants viewed videos of moving water. These tasks were completed daily for 8 days. MAIN OUTCOME MEASURES: Spatiotemporal walking variables were assessed using accelerometers in the laboratory (baseline and posttraining assessments) and continuously at home during the training period. Variables included daily activity, walking speed, stride length, stride frequency, leg swing time, and gait asymmetry. Questionnaires including the 39-item Parkinson Disease Questionnaire (PDQ-39) were administered to determine self-reported change in walking, as well as feasibility. RESULTS: At posttraining assessment, only the gait observation group reported significantly improved mobility (PDQ-39). No improvements were seen in accelerometer-derived walking data. Participants found the at-home training tasks and accelerometer feasible to use. CONCLUSIONS: Participants found procedures feasible and reported improved mobility, suggesting that observational training holds promise in the rehabilitation of walking in PD. Observational training alone, however, may not be sufficient to enhance walking in PD. A more challenging and adaptive task, and the use of explicit perceptual learning and practice of actions, may be required to effect change

O uso da eletromiografia para identificação de fadiga na dor lombar baixa

É descrita uma técnica de eletromiografia (EMG) de superfície, desenvolvida para fornecer uma medida objetiva da função muscular para-espinhal em pacientes com dor lombar baixa (LBP). O equipamento, denominado de Back Analyses System (BAS) registra alterações nos parâmetros de amplitude e espectro, a partir de seis eletrodos de EMG, durante uma série de tarefas isométricas fatigantes com retro-alimentação visual da força. Mudanças na freqüência média da EMG – um índice de fadiga, foram previamente comparadas, neste relato, em diferentes localizações dos eletrodos e em diferentes níveis de força constante, em sujeitos-controle saudáveis. Os resultados demonstram que há um padrão característico “normal” de fadiga entre as várias regiões musculares para-espinhais, que é simétrico em relação às regiões para-vertebrais contra-laterais, contudo significativamente diferente ao se comparar níveis lombares alto e baixo. Alterações na freqüência média da EMG, durante uma contração sustentada, são significativamente aumentadas com aumentos do nível de força da contração. Em pacientes com LBP crônica, o grau de mudança da freqüência média é significativamente maior que em sujeitos-controle num mesmo nível de força. Estes achados são provavelmente relacionados com o descondicionamento muscular resultante do desuso crônico. Outros achados são relatados através de protocolos do BAS entre pacientes com LBP sub-aguda com incapacidade de moderada a severa. Estes pacientes apresentam um padrão assimétrico distinto de fadiga muscular medido através de parâmetros de amplitude e freqüência média. Este padrão é interpretado como uma maneira de medir desequilíbrios (desbalanços) musculares resultantes comportamento de escape (evitar) ou de inibição associada à dor. As implicações destas descobertas com EMG peculiar são discutidas em termos de estratégias de tratamentos diferenciais para a LBP.A surface EMG technique is described which was developed to provide an objective measure of paraspinal muscle function in patients with LBP. The device, referred to as a Back Analysis System (BAS) records changes in spectral and amplitude parameters from 6 EMG electrodes during a series of fatiguing isometric tasks that rely on visual force-feedback. Changes in the EMG median frequency, a fatigue index, are first compared in this report for different electrode locations and different constant force levels in healthy control subjects. The results demonstrate that there is a characteristic “normal” pattern of fatigue among the various paraspinal muscle sites that is symmetric with respect to contra lateral paravertebral locations, but significantly different when comparing upper and lower lumbar levels. Changes in EMG median frequency during a sustained contraction are significantly increased with increases in force level of the contraction. In patients with chronic LBP in remission, the degree of median frequency change is significantly higher than in control subjects matched for strength. These findings are likely related to muscle deconditioning resulting from chronic disuse. Other findings are reported from BAS protocols among sub-acute LBP patients with moderate to severe disability. These patients have a distinctive asymmetrical pattern of muscle fatigue as measured by the median frequency and amplitude parameters. This pattern is interpreted as a way of measuring muscle imbalances resulting from to pain-related inhibition or avoidance behavior. Implications of these characteristic EMG findings are discussed in terms of differential treatment strategies for LBP

Looks can be deceiving : the deceptive milkcaps (Lactifluus, Russulaceae) exhibit low morphological variance but harbour high genetic diversity

The ectomycorrhizal genus Lactifluus is known to contain many species complexes, consisting of morphologically very similar species, which can be considered cryptic or pseudocryptic. In this paper, a thorough molecular study is performed of the Glade around Lactifluus deceptivus (originally described by Peck from North America) or the deceptive milkcaps. Even though most collections were identified as L. deceptivus, the Glade is shown to contain at least 15 species, distributed across Asia and America, indicating that the L. deceptivus Glade represents a species complex. These species are morphologically very similar and are characterized by a tomentose pileus with thin-walled hyphae and a velvety stipe with thick-walled hyphae. An ITS1 sequence was obtained through Illumina sequencing for the lectotype of L. deceptivus, dating from 1885, revealing which Glade represents the true L. deceptivus. In addition, it is shown that three other described species also belong to the L. deceptivus Glade: L. arcuatus, L. caeruleitinctus and L. mordax and molecularly confirmed that L. tomentoso-marginatus represents a synonym of L. deceptivus. Furthermore, two new Neotropical species are described: Lactifluus hallingii and L. domingensis

The role of nondeclarative memory in the skill for language::Evidence from syntactic priming in patients with amnesia

Contains fulltext : 172885.pdf (publisher's version ) (Closed access)Syntactic priming, the phenomenon in which participants adopt the linguistic behaviour of their partner, is widely used in psycholinguistics to investigate syntactic operations. Although the phenomenon of syntactic priming is well documented, the memory system that supports the retention of this syntactic information long enough to influence future utterances, is not as widely investigated. We aim to shed light on this issue by assessing patients with Korsakoff's amnesia on an active-passive syntactic priming task and compare their performance to controls matched in age, education, and premorbid intelligence. Patients with Korsakoff's syndrome display deficits in all subdomains of declarative memory, yet their nondeclarative memory remains intact, making them an ideal patient group to determine which memory system supports syntactic priming. In line with the hypothesis that syntactic priming relies on nondeclarative memory, the patient group shows strong priming tendencies (12.6% passive structure repetition). Our healthy control group did not show a priming tendency, presumably due to cognitive interference between declarative and nondeclarative memory. We discuss the results in relation to amnesia, aging, and compensatory mechanisms.9 p

Dire necessity or mere opportunity? Recurring commercialization of peat exploited from raised bog commons in the Low Countries

Traditional commons scholarship, and in particular common-pool resource (CPR) theory, argues that historical commons institutions were autonomous, little influenced by either markets or states, and that commercialisation and sustainable collective use of common-pool resources were incompatible. This paper examines to what extent this view holds true. It does so by analysing historical sources on two local cases of peat commercialisation from raised bog commons in the early modern Low Countries: the Bakelse gemeint in the Peel region, and the commune de Xhoffraix in the Hautes Fagnes. The significance of peat commercialisation from commons was notably in its permanence, recurrence, and/or regional outreach, rather than in its limited volume share in total peat exploitation. Dire financial need of communities with high debts and taxes can partly explain the motives for peat commercialisation. Viewed over the longer term mere opportunity to gain some money was a plausible additional motive. In addition, stately institutions could influentially interfere in commons management in times of (internal) conflict. Sources indicate a pragmatic attitude towards peat commercialisation by these institutions, possibly to foster social peace and local prosperity in times of resource contestation and economic hardship. This study adds a novel intermediate category of peat exploitation to the traditional binary subdivision in domestic peat extraction from commons versus large-scale commercial exploitation of privatised bogs. We demonstrate that long-term use of common-pool resources could go together with a moderate degree of commercialisation. Rather than being fully autonomous, commons institutions were - structurally or at times of internal conflict - clearly impacted by markets, notions of private property, and stately institutions

2019: The Year of Teledentistry in France?

In France, access to a dentist for elderly people, disabled people or inmates is limited. A person’s access to a dentist decreases by 25% when joining a nursing home. A national report&nbsp;mentioned that 85% of residents in nursing homes didn’t have access to a dentist in the past year and 42% in the last 5 years. There are fewer data on disabled people, but 48% of people with disabilities have, at least, one important issue related to oral health. Two examples of teledentistry, the e-DENT project from University Hospital of Montpellier and the TEL-E-DENT project from the public Hospital of Guéret, are presented to describe how teledentistry works in France, the current legal framework, remuneration of teledentistry and the pros and cons of teledentistry in France.&nbsp;2019 will be crucial for the development of teledentistry as a number official decisions will be made that will influence the implementation of this kind of activity